Consumer medicine information

Enbrel

Etanercept

BRAND INFORMATION

Brand name

Enbrel

Active ingredient

Etanercept

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Enbrel.

SUMMARY CMI

Enbrel®

Consumer Medicine Information (CMI) summary

The full CMI on the next page has more details. If you are worried about using this medicine, speak to your doctor or pharmacist.

1. Why am I using Enbrel?

Enbrel contains the active ingredient etanercept. Enbrel is used to treat specific types of joint inflammation and skin conditions, namely rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, non-radiographic axial spondyloarthritis (nr-AxSpA), psoriatic arthritis and plaque psoriasis.

For more information, see Section 1. Why am I using Enbrel? in the full CMI.

2. What should I know before I use Enbrel?

Do not use if you have ever had an allergic reaction to etanercept or any of the ingredients listed at the end of the CMI.

Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.

For more information, see Section 2. What should I know before I use Enbrel? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with Enbrel and affect how it works.

A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use Enbrel?

  • Enbrel is given in adults either once a week as a 50 mg dose, or as two separate 25 mg doses 3-4 days apart. In children, the dose and frequency depend on weight and the disease.
  • Enbrel is injected under the skin and is for single use in one patient only. Refer to Instructions for Use provided in the pack.
  • Enbrel dose-dispenser cartridges are intended for use with the SmartClic injection device.

More instructions can be found in Section 4. How do I use Enbrel? in the full CMI.

5. What should I know while using Enbrel?

Things you should do
  • Remind any doctor or dentist you visit that you are using Enbrel.
  • Tell your doctor if you have latex allergies.
  • Ensure children are up to date with vaccinations prior to starting Enbrel.
  • Tell your doctor if you are at risk of blood poisoning or infections, such as leg ulcers.
  • Contraception is recommended to avoid becoming pregnant during Enbrel therapy and for 3 weeks after discontinuation of Enbrel therapy. Inform your doctor immediately if you are planning pregnancy or are pregnant.
Things you should not do
  • Do not stop using this medicine suddenly, unless advised by your doctor.
  • Do not shake the solution of Enbrel after you have added the sterile water for injection.
Looking after your medicine
  • Keep Enbrel in the fridge between 2°C and 8°C. Do not freeze.
  • Store Enbrel in the cartons to protect from light.
  • Enbrel powder for injection must be discarded 6 hours after preparation into a solution.

For more information, see Section 5. What should I know while using Enbrel? in the full CMI.

6. Are there any side effects?

Common side effects include a mild reaction in the area of injection, infections and inflammation, allergic reactions, rash, itching, fever, headache and raised liver enzymes.

For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.



FULL CMI

Enbrel®

Active ingredient(s): etanercept

Consumer Medicine Information (CMI)

This leaflet provides important information about using Enbrel. You should also speak to your doctor or pharmacist if you would like further information or if you have any concerns or questions about using Enbrel.

Where to find information in this leaflet:

1. Why am I using Enbrel?
2. What should I know before I use Enbrel?
3. What if I am taking other medicines?
4. How do I use Enbrel?
5. What should I know while using Enbrel?
6. Are there any side effects?
7. Product details

1. Why am I using Enbrel?

Enbrel contains the active ingredient etanercept. Etanercept is a biotechnology-derived protein that works by binding to and inactivating Tumour Necrosis Factor (TNF), a naturally occurring chemical in your bloodstream that contributes to pain and swelling in the joints.

Enbrel is used in the treatment of specific inflammatory joint or skin conditions by reducing the pain and swelling of rheumatoid arthritis and psoriasis, helping to treat the skin lesions of psoriasis and psoriatic arthritis, and improving the condition of patients with ankylosing spondylitis, non-radiographic axial spondyloarthritis (nr-AxSpA) and juvenile idiopathic arthritis.

Your doctor may have prescribed Enbrel for another reason. Ask your doctor if you have any questions about why Enbrel has been prescribed for you.

2. What should I know before I use Enbrel?

Warnings

Do not use Enbrel if:

  1. you are allergic to etanercept, latex or any of the ingredients listed at the end of this leaflet.
Always check the ingredients to make sure you can use this medicine.
  1. you have, or are at risk of developing, sepsis (blood poisoning), or long-term or localised infection (for example, leg ulcers).
Sepsis is a serious infection causing fever, headache, joint aches and pains, sore or weak muscles, and increased heart rate. Enbrel can affect your body's ability to fight a serious infection.
If you are not sure whether you have a serious infection, check with your doctor.
  1. you are currently taking anakinra or other similar medicines known as Interleukin-1 antagonists.
  2. the packaging is torn or shows signs of tampering
  3. the expiry date printed on the pack has passed.
If you use Enbrel after the expiry date has passed, it may have no effect at all, or worse, have an entirely unexpected effect.

Check with your doctor if you:

  • have any allergies to:
    - latex (the needle cover of the pre-filled syringe, dose-dispenser cartridge, auto-injector and the rubber closure of the diluent syringe (vial presentation) contain dry natural rubber),
    - any other medicines,
    - any other substances, such as foods, preservatives or dyes.
  • have any other medical conditions, especially:
    - serious infection including sepsis, tuberculosis or a history of recurring infections,
    - low resistance to disease,
    - diabetes,
    - liver problems or hepatitis B or hepatitis C, viruses that affect the liver,
    - heart failure,
    - blood disorders,
    - cancer,
    - are about to have major surgery,
    - nerve disorders including multiple sclerosis or optic neuritis (inflammation of the nerves of the eyes),
    - seizures,
    - chickenpox or have been recently exposed to chickenpox.
  • take any medicines for any other condition,
  • you are pregnant or intend to become pregnant,
  • you are breast-feeding or plan to breast-feed.

If you are not sure whether you should start taking this medicine, talk to your doctor.

During treatment, you may be at risk of developing certain side effects. It is important you understand these risks and how to monitor for them. See additional information under Section 6. Are there any side effects?

Pregnancy and breastfeeding

Check with your doctor if you are pregnant or intend to become pregnant.

The effects of Enbrel in pregnant women are not well understood, therefore Enbrel should only be used during pregnancy if clearly needed.

Contraception is recommended to avoid becoming pregnant during Enbrel therapy and for 3 weeks after discontinuation of Enbrel therapy. Inform your doctor immediately if you are planning pregnancy or are pregnant.

If you become pregnant while using Enbrel, contact your doctor. Your doctor will help you to decide whether the benefits of treatment outweigh the potential risk to your baby.

Talk to your doctor if you are breastfeeding or intend to breastfeed.

Small amounts of Enbrel can pass into breast milk. If you are breastfeeding, you should discuss the use of Enbrel and the options available with your doctor.

It is important that you discuss with your doctor the use of Enbrel during pregnancy or breastfeeding before the baby receives any vaccine.

Use in Children

  • Enbrel is not currently recommended for use in children under 2 years of age as it has not been tested in children under 2 years.
  • Make sure that children are up to date with all vaccinations (including chickenpox) before they start treatment with Enbrel.
    Live vaccines, such as oral polio vaccine, should not be given while receiving Enbrel.

This medicine is available only with a doctor's prescription.

Enbrel is not addictive.

3. What if I am taking other medicines?

Tell your doctor or pharmacist if you are taking any other medicines, including any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines may interfere with Enbrel and affect how it works.

Medicines that increase risk of side effects when used with Enbrel:

  • abatacept and Interleukin-1 antagonists such as anakinra. These medicines should not be used with Enbrel.
  • cyclophosphamide, a medicine used to treat cancer or prevent transplant rejection. Use with Enbrel is not recommended.
  • sulfasalazine.

Medicines that Enbrel may interfere with:

  • some vaccines
  • warfarin, a medicine used to thin the blood and prevent blood clots
  • digoxin, a medicine used to improve the strength and efficiency of the heart, or to control the rate and rhythm of the heartbeat
  • medicines used to treat diabetes

Check with your doctor or pharmacist if you are not sure about what medicines, vitamins or supplements you are taking and if these affect Enbrel.

4. How do I use Enbrel?

Your doctor will tell you how to inject Enbrel. A different site should be used for each new injection. Each new injection should be given at least 3 cm from an old site.

How much to use

Adults

  • The recommended dose for adults is 50 mg per week, injected under the skin. This can be given as either a single 50 mg injection once weekly, or two separate 25 mg injections, 3-4 days apart. Your doctor may determine a different frequency at which to inject Enbrel.
  • If you are being treated for psoriasis, your doctor may prescribe a higher dose of Enbrel when you first begin your treatment.
  • If you are being treated for nr-AxSpA and Enbrel has no effect on your condition within 12 weeks, your doctor may tell you to stop using this medicine
  • Follow the instructions provided and use Enbrel until your doctor tells you to stop.

Children

  • The appropriate dose and frequency of dosing for children and teenagers will depend on body weight and the disease. Your child's doctor will provide detailed directions for preparing and measuring the appropriate dose for your child.
  • For juvenile idiopathic arthritis, the recommended dose is 0.8 mg of Enbrel per kg bodyweight (up to a maximum of 50 mg) given once weekly. Enbrel may also be given twice weekly at a dose of 0.4 mg of Enbrel per kg bodyweight (up to a maximum of 25 mg).
  • For psoriasis patients, the recommended dose is 0.8 mg of Enbrel per kg bodyweight (up to a maximum of 50 mg) given once weekly. If Enbrel has no effect on the child's condition after 12 weeks, your doctor may tell you to stop using this medicine.

When to use Enbrel

  • Enbrel should be used at the same time each week or at the same time every 3-4 days as directed by your doctor.

How to use Enbrel

Your doctor will supervise and advise you on how to use Enbrel when you first start. If your doctor thinks it is appropriate, they can train you on how to self-inject Enbrel.

Enbrel should be administered according to the instructions provided in the Instructions for Use leaflet included with the medicine and the user manual provided with the SmartClic injection device for the dose-dispenser cartridge.

Powder for injection:

  • Enbrel powder for injection contains no additives that would prevent the growth of bacteria once the powder is dissolved. For this reason, the vial should not be stored for more than 6 hours after dissolving the powder with the diluent provided.

Solution for injection only:

  • After allowing the Enbrel solution to reach room temperature (approximately 15 to 30 minutes), immediate use is recommended.
  • Each vial or syringe of Enbrel is for single use only, in one patient only. Discard any residue.

Dose-dispenser cartridge for use in the SmartClic injection device only:

  • After allowing the Enbrel dose-dispenser cartridge to reach room temperature (approximately 30 minutes), immediate use is recommended.
  • Each dose-dispenser cartridge (for use in SmartClic injection device) is for single use in one patient only.
  • The SmartClic injection device is supplied separately by the doctor who prescribed Enbrel to you, or by contacting Pfizer (www.enbrel.com.au or call 1800 362 735).

Follow all directions given to you by your doctor or pharmacist carefully.

They may differ from the information contained in this leaflet.

If you are injecting Enbrel yourself, you must follow the detailed instructions provided in the leaflet inside the pack.

Enbrel is injected under the skin. When using the syringes provided with the Enbrel vial, pre-filled syringe or dose-dispenser cartridge presentations, it is important that you do not pull back on the plunger. Enbrel can be injected by your doctor, nurse, carer or by yourself.

When you have finished injecting Enbrel, discard the needle and syringe into a sharps container.

If you do not understand the instructions for injecting Enbrel found in the carton, ask your doctor or pharmacist for help.

To help you remember, use a diary to write in the days of the week you or your child should have an Enbrel injection.

You should continue to inject Enbrel for as long as your doctor recommends.

Never inject more than the dose recommended by your doctor.

If you feel that the effect of Enbrel is too strong or too weak, talk to your doctor or pharmacist.

If you forget to use Enbrel

Enbrel should be used regularly at the same time each week, or the same time every 3-4 days as agreed with your doctor. If you miss your dose at the usual time, you should inject the next dose as soon as you remember if it is within 48 hours since the scheduled dose time.

If it is almost time for your next dose i.e. within 48 hours of your next dose, skip the dose you missed and take your next dose when you are meant to.

Do not take a double dose to make up for the dose you missed.

If you use too much Enbrel

If you think that you have used too much Enbrel, you may need urgent medical attention.

You should immediately:

  • phone the Poisons Information Centre
    (by calling 13 11 26), or
  • contact your doctor, or
  • go to the Emergency Department at your nearest hospital.

You should do this even if there are no signs of discomfort or poisoning.

Always take the labelled medicine carton with you, even if it is empty.

You may need urgent medical attention. There is very limited data on overdose with Enbrel. Ask your doctor if you have any concerns.

5. What should I know while using Enbrel?

Things you should do

Tell any other doctors, dentists and pharmacists who are treating you that you are using Enbrel.

Tell your doctor if Enbrel is not making your condition better.

Keep a record of the Lot number of each Enbrel pack that you use.

Call your doctor straight away if you:

  • Have or develop any serious infection while using Enbrel. Do not inject any more Enbrel and contact your doctor immediately.
  • Have any symptoms such as persistent fever, sore throat, bruising, bleeding or paleness.
    These symptoms may point to the existence of a potentially life-threatening blood disorder, which may require you to stop taking Enbrel.

Remind any doctor or dentist you visit that you are using Enbrel.

Things you should not do

  • Do not stop using this medicine suddenly or lower the dosage without checking with your doctor.
  • Do not shake the solution of Enbrel after you have added the sterile water for injection. Shaking the solution will cause it to froth (create lots of bubbles). This may affect the medicine so that it may not work.
  • Do not stop using Enbrel because you are feeling better, unless your doctor advises you to. Your condition may flare up if you reduce the dose or stop using Enbrel.
  • Do not give Enbrel to anyone else even if they have the same condition as you.
  • Do not use Enbrel to treat any other complaints unless your doctor tells you to.
  • Do not stop using Enbrel, or lower the dosage, without checking with your doctor.

Driving or using machines

It is not known whether Enbrel causes dizziness or drowsiness.

Drinking alcohol

No information is available.

Looking after your medicine

Follow the instructions in the carton on how to take care of your medicine properly.

Keep Enbrel in a refrigerator where the temperature stays between 2°C and 8°C.

Keep it away from moisture, heat or sunlight; for example, do not store it:

  • in the bathroom or near a sink, or
  • in the car or on window sills.

Store Enbrel pre-filled syringes, auto-injectors and dose-dispenser cartridges in their cartons to protect them from light.

Heat and dampness can destroy some medicines.

If it is not possible to store Enbrel in the refrigerator, it may be stored out of the refrigerator (below 25°C) for up to 4 weeks (e.g. when travelling).

If you have stored Enbrel at room temperature for any period of time (even if returned to the refrigerator) you must use it within 4 weeks from the time you first took it out of the refrigerator, or else you must discard it.

Do not use Enbrel if it has been exposed to high temperatures or has been out of the refrigerator for more than 4 weeks.

For additional advice on storing Enbrel, contact Pfizer Medical Information on 1800 362 735.

Do not use this medicine after the expiry date.

Keep it where young children cannot reach it.

When to discard your medicine

Powder for injection only:

Dispose of any Enbrel solution that has been prepared more than 6 hours ago, but not used.

Enbrel powder in vials does not contain a preservative, therefore, once the powder is mixed, the solution may spoil after 6 hours.

Getting rid of any unwanted medicine

If you no longer need to use this medicine or it is out of date, take it to any pharmacy for safe disposal.

6. Are there any side effects?

All medicines can have side effects. If you do experience any side effects, most of them are minor and temporary. However, some side effects may need medical attention.

See the information below and, if you need to, ask your doctor or pharmacist if you have any further questions about side effects.

Common side effects

Common side effectsWhat to do
Injection site reactions:
  • Itching
  • Bruising
  • Redness
  • Bleeding, swelling, pain or hardness around the injection site.
Infections:
  • Cold
  • Sinus infections
Allergic reactions
Symptoms of an allergic reaction may include:
  • wheezing, shortness of breath, difficulty breathing, or a tight feeling in your chest,
  • swelling of the face, lips, tongue or other parts of the body,
  • rash, itching, hives or flushed red skin,
  • dizziness or light-headedness.
Other:
  • Headaches
  • Fever
Speak to your doctor if you have any of these common side effects and they worry you.

Serious side effects

Serious side effectsWhat to do
Infections:
  • Tuberculosis
  • Blood poisoning (sepsis)
  • Signs of an infection such as fever, chills, mouth ulcers or sore throat
Lung disease:
  • Breathlessness during exercise or a dry cough
Soft tissue infections:
  • Bumps or sores that do not heal, are swollen, red or have pus
Nervous system disorders:
  • Seizures, numbness or tingling throughout your body, weakness in your arms and/or legs and dizziness, or problems with your eyesight.
Inflammation:
  • Spinal cord
  • Inner eye
  • Blood vessels in the skin or lymph glands
  • Signs of inflammatory bowel such as diarrhoea or mucus or blood in your stools, stomach cramps, fever or weight loss.
Allergic reaction:
  • Swelling of the face, lips or tongue which may cause difficulty in swallowing or breathing, or hives.
Lupus or lupus-like syndrome:
  • Weight changes, persistent rash, fever, joint or muscle pain or fatigue
Immune system disorders:
  • Skin rash, blisters and ulcers on the skin, in the mouth or airways
Blood disorders:
  • Tiredness, headaches, shortness of breath when exercising, dizziness, paleness, nose bleeds, unusual bleeding or bruising or more frequent infections.
Heart failure:
  • shortness of breath, persistent cough, difficulty exercising, fast or irregular heartbeat, swelling in the legs or feet, tiredness and weakness.
Call your doctor straight away, or go straight to the Emergency Department at your nearest hospital if you notice any of these serious side effects.

There have been reports of some types of cancer developing in patients using Enbrel and other TNF blocking medicines. These include skin cancers, cancers that affect the lymph system called lymphoma and Kaposi's sarcoma (which also affects the organs, skin, mouth, nose or throat), or affect the blood system called leukaemia. The role of Enbrel in the development of cancer is not known.

Tell your doctor or pharmacist if you notice anything else that may be making you feel unwell.

Other side effects not listed here may occur in some people.

Reporting side effects

After you have received medical advice for any side effects you experience, you can report side effects to the Therapeutic Goods Administration online at www.tga.gov.au/reporting-problems. By reporting side effects, you can help provide more information on the safety of this medicine.

Always make sure you speak to your doctor or pharmacist before you decide to stop taking any of your medicines.

7. Product details

This medicine is only available with a doctor's prescription.

What Enbrel contains

Powder for injection

Active ingredient
(main ingredient)		Etanercept
Other ingredients
(inactive ingredients)		Mannitol
Trometamol
Sucrose

Solution for injection

Prefilled syringe, Auto-injector and Dose-dispenser cartridge

Active ingredient
(main ingredient)		Etanercept
Other ingredients
(inactive ingredients)		Sucrose
Sodium chloride
Arginine hydrochloride
Monobasic sodium phosphate dihydrate
Dibasic sodium phosphate dihydrate
Water

Do not take this medicine if you are allergic to any of these ingredients.

Enbrel powder for injection and solution for injection do not contain lactose, gluten, tartrazine or any other azo dyes.

What Enbrel looks like

Powder for injection:

Enbrel powder for injection is supplied as a pack containing:

  • Four single dose glass vials of Enbrel powder.

Each vial of Enbrel contains 25 mg of the active ingredient, etanercept.

  • Four pre-filled glass syringes of sterile water for injections.

The rubber closure of the diluent syringe contains dry natural rubber (a derivative of latex). The powder must be dissolved in 1 mL of the sterile water for injections before use.

  • Four sterile vial adaptors and four sterile needles.

The vial adaptor is for delivering the water into the Enbrel vial. It should be replaced with a needle for injection after the Enbrel solution has been drawn up into the syringe.

(AUST R 90456)

Pre-filled Syringe (Solution for injection):

Enbrel Pre-filled Syringe is supplied in a kit containing:

  • Four single-dose pre-filled glass syringes containing Enbrel solution.

Each syringe contains 50 mg of etanercept in 1 mL of Enbrel solution. The needle cover of the pre-filled syringe presentation contains dry natural rubber (a derivative of latex).

  • Four alcohol swabs.

(AUST R 124422)

Auto-injector (Solution for injection)

Enbrel Auto-injector is supplied in a kit containing:

  • Either one or four single-dose pre-filled glass syringes, each housed in a plastic Auto-injector.

Each syringe contains 50 mg of etanercept in 1 mL of Enbrel solution. The needle cap of the Auto-injector contains dry natural rubber (a derivative of latex).

  • Two or four alcohol swabs are also provided in the kit.

(AUST R 157622)

Dose-dispenser cartridge (Solution for injection) for use with the SmartClic injection device (supplied separately).

Enbrel dose-dispenser cartridge is supplied in a pack containing:

  • Either one or four single-use dose-dispenser cartridges.

Each cartridge contains either 25 mg of etanercept in 0.5 mL of Enbrel solution or 50 mg of etanercept in 1 mL of Enbrel solution. The needle cap of the dose-dispenser cartridge contains dry natural rubber (a derivative of latex).

  • Two or eight alcohol swabs are also provided in the pack.

(AUST R 352090 and 352091)

Not all presentations may be marketed.

Who distributes Enbrel

Enbrel is supplied in Australia by:

Pfizer Australia Pty Ltd
Sydney NSW
Toll Free Number: 1800 675 229
www.pfizermedinfo.com.au

Administration kit is prepared by:

Pfizer Manufacturing Belgium
Rijksweg 12
Puurs, Belgium

This leaflet was prepared in January 2024.

Published by MIMS March 2024

BRAND INFORMATION

Brand name

Enbrel

Active ingredient

Etanercept

Schedule

S4

 

1 Name of Medicine

Etanercept.

2 Qualitative and Quantitative Composition

Powder for injection.

Each vial of Enbrel powder for injection contains 25 mg of the active ingredient, etanercept. The content of the diluent syringe is 1 mL of sterile water for injections.

Pre-filled syringe (solution for injection).

Each syringe of Enbrel solution for injection contains either 25 mg* (in 0.5 mL) or 50 mg (in 1 mL) of etanercept.

Dose-dispenser cartridge (solution for injection).

Each dose-dispenser cartridge of Enbrel solution for injection contains either 25 mg (in 0.5 mL) or 50 mg (in 1 mL) of etanercept.

Auto-injector (solution for injection).

The Enbrel prefilled auto-injector contains 50 mg of etanercept.
* Not all presentations may be marketed.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Powder for solution for injection.

Following reconstitution with water for injections, Enbrel is a colourless to slightly yellow or pale brown and clear to slightly opalescent solution, with a pH of 7.1-7.7.

Solution for injection.

Enbrel solution for injection in the pre-filled syringe, auto-injector and dose-dispenser cartridge is a clear to opalescent, colourless to yellow or pale brown solution with a pH of 6.1-6.5. The liquid may contain trace levels of translucent to white amorphous particles.
Enbrel 25 mg and 50 mg solution for injection in the single-use dose-dispenser cartridge is for use in a Multi-Use Single-Patient device (MUSP).

4 Clinical Particulars

4.1 Therapeutic Indications

Enbrel is indicated for the treatment of:

Adults.

Rheumatoid arthritis.

Active, adult rheumatoid arthritis (RA) in patients who have had inadequate response to one or more disease modifying antirheumatic drugs (DMARDs). Enbrel can be used in combination with methotrexate.
Severe, active rheumatoid arthritis in adults to slow progression of disease associated structural damage in patients at high risk of erosive disease.

Psoriatic arthritis.

The signs and symptoms of active and progressive psoriatic arthritis in adults, when the response to previous disease modifying antirheumatic therapy has been inadequate. Enbrel has been shown to reduce the rate of progression of joint damage as measured by X-ray and to improve physical function.

Plaque psoriasis.

Adult patients with moderate to severe chronic plaque psoriasis who are candidates for phototherapy or systemic therapy.

Ankylosing spondylitis.

The signs and symptoms of active ankylosing spondylitis in adults.

Nonradiographic axial spondyloarthritis.

Treatment of adults with active* nonradiographic axial spondyloarthritis with objective signs of inflammation as indicated by elevated C-reactive protein (CRP) and/or MRI change who have had an inadequate response to NSAIDs.
* Active disease is defined as a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score of ≥ 4.

Children and adolescents.

Juvenile idiopathic arthritis.

Active polyarthritis (rheumatoid factor positive or negative) in children and adolescents, aged 2 to 17 years, who have had an inadequate response to one or more DMARDs.
Active extended oligoarthritis in children and adolescents, aged 2 to 17 years, who have had an inadequate response to, or who have proved intolerant to, methotrexate.
Active enthesitis related arthritis in adolescents, aged 12 to 17 years, who have had an inadequate response to, or who have proved intolerant to, conventional therapy.
Active psoriatic arthritis in adolescents, aged 12 to 17 years, who have had an inadequate response to, or who have proved intolerant to, methotrexate.
Enbrel has not been studied in children aged less than 2 years.

Paediatric plaque psoriasis.

Chronic, severe plaque psoriasis in children and adolescents from 4 to 17 years, who are inadequately controlled by, or are intolerant to, other systemic therapies or phototherapies. Duration of therapy to be no longer than 24 weeks and treatment to be ceased after 12 weeks if a significant PASI response is not achieved.

4.2 Dose and Method of Administration

Treatment should be initiated and supervised by specialist physicians experienced in the diagnosis and treatment of rheumatoid arthritis, juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, nonradiographic axial spondyloarthritis, plaque psoriasis or paediatric plaque psoriasis. Patients may self inject only if their physician determines that it is appropriate and with medical follow-up, as necessary, after proper training in injection technique.

Adults.

Rheumatoid arthritis, psoriatic arthritis, nonradiographic axial spondyloarthritis and ankylosing spondylitis.

The recommended dose of Enbrel is 50 mg per week, given as a subcutaneous injection, either once weekly as a single 50 mg injection or twice weekly as two separate 25 mg injections given 3-4 days apart.
Available data in nonradiographic axial spondyloarthritis suggest a clinical response is usually achieved within 12 weeks of treatment. Continued therapy should be carefully reconsidered in a patient not responding within this time period.

Plaque psoriasis.

The recommended dose of Enbrel is 50 mg per week given once weekly (single 50 mg injection) or twice weekly (single 25 mg injections given 3-4 days apart) as a subcutaneous injection. Higher responses may be achieved from initial treatment for up to 12 weeks with a dose of 50 mg given twice weekly, after which, the dose should be reduced to the standard dose of 50 mg per week. Treatment should be discontinued in patients who do not show a significant PASI response after 12 weeks. If retreatment with Enbrel is indicated, the dose used should be 50 mg per week.

Elderly patients.

Elderly RA patients (age ≥ 65 years) show similar safety, efficacy and pharmacokinetic profiles compared to younger adult patients treated with Enbrel. Dose adjustment is not needed for the elderly. However, as with other medicinal products, greater sensitivity in some older patients cannot be ruled out.

Children and adolescents.

The dosage of Enbrel is based on bodyweight for paediatric patients. Patients weighing less than 62.5 kg should be accurately dosed on a mg/kg basis using Enbrel powder for injection (see below for dosing for specific indications). Patients weighing 62.5 kg or more and receiving once weekly doses may be dosed using a 50 mg (in 1 mL) fixed-dose pre-filled syringe or auto-injector.

Juvenile idiopathic arthritis (age 2 years and above).

The recommended dose for children 2-17 years of age is 0.8 mg/kg (up to a maximum of 50 mg per dose) given once weekly as a subcutaneous injection, or 0.4 mg/kg (up to a maximum of 25 mg), given twice weekly with an interval of 3-4 days between doses.

Paediatric plaque psoriasis (age 4 years and above).

The recommended dose is 0.8 mg/kg (up to a maximum of 50 mg per dose), given once weekly as a subcutaneous injection for up to 24 weeks. Treatment should be discontinued in patients who do not show a significant PASI response after 12 weeks. If retreatment with Enbrel is indicated, the above guidance on treatment duration should be followed.

Renal impairment.

No dosage adjustment is required.

Hepatic impairment.

No dosage adjustment is required.

Method of administration.

Instructions for use, handling and disposal.

Reconstitution (powder for injection only). Enbrel contains no antibacterial preservative and therefore, solutions prepared with water for injections should be administered as soon as possible and within six hours following reconstitution. In the absence of compatibility studies, Enbrel must not be mixed with other medicinal products.
Reconstitute the Enbrel powder aseptically by injecting 1 mL of sterile water for injections very slowly into the vial with the vial adaptor attached to the syringe. Gently swirl the contents to avoid excessive foaming. Some foaming will occur, this is normal. To avoid excessive foaming, do not shake or vigorously agitate. Dissolution of Enbrel usually takes less than 10 minutes.
Visually inspect the solution for particulate matter and discolouration prior to administration. The solution should not be used if discoloured or cloudy, or if particulate matter remains. Withdraw the solution into the empty syringe, removing only the dose to be given from the vial. Some foam or bubbles may remain in the vial. Do not filter reconstituted solution during preparation or administration. Do not use Enbrel if all the powder in the vial is not dissolved within 10 minutes. Start again with another vial. Once the Enbrel solution has been aspirated into the syringe, discard the vial adaptor and replace with a needle from the pack for injection.
Before injecting. Sites for self injection include thigh, abdomen or upper arm. Injection sites should be rotated. New injections should be given at least 3 cm from an old site and never into areas where the skin is tender, bruised, red or hard (see Instructions for Use leaflet supplied with Enbrel).

Powder for injection.

The reconstituted solution should be colourless to slightly yellow or pale brown and clear to slightly opalescent.

Prefilled syringe (solution for injection).

Before injecting, Enbrel single use prefilled syringes should be allowed to reach room temperature (approximately 15 to 30 minutes). The needle cover should not be removed during this period. The solution should be clear to opalescent, colourless to yellow or pale brown and liquid may contain trace levels of translucent to white amorphous particles. Otherwise, do not inject the solution. Use a different Enbrel prefilled syringe, then contact your pharmacist for assistance.

Auto-injector (solution for injection).

Before injecting, Enbrel single-use auto-injector should be allowed to reach room temperature (approximately 15 to 30 minutes). Immediate use is then recommended. The needle cover should not be removed while allowing the auto-injector to reach room temperature. By looking through the inspection window, the solution should be clear to opalescent and colourless to yellow or pale brown and liquid may contain trace levels of translucent to white amorphous particles. Otherwise, do not inject the solution. Use a different Enbrel auto-injector, then contact your pharmacist for assistance.

Dose-dispenser cartridge (solution for injection).

Before injecting, Enbrel single-use dose-dispenser cartridge should be allowed to reach room temperature (approximately 15 - 30 minutes). The needle cover should not be removed during this period. By looking through the inspection window, the solution should be clear to opalescent, colourless to yellow or pale brown, and the liquid may contain trace levels of translucent to white amorphous particles. Otherwise, do not inject the solution. Use a different Enbrel dose-dispenser cartridge, then contact your pharmacist for assistance.
Enbrel solution for injection in the dose-dispenser cartridge is intended for single-use in conjunction with the MUSP. After proper training on the injection technique, patients may self-inject using the MUSP injection device with the single use dose-dispenser cartridge if their physician determines that it is appropriate and with medical follow-up as necessary. The physician should discuss with the patient which injection presentation option is the most appropriate.
For administration, the Instructions for Use leaflet included with the Enbrel dose-dispenser cartridges and the user manual provided with the MUSP injection device should be followed.
The MUSP will deliver the full content of the dose-dispenser cartridge.
Administration. If a patient is to self administer Enbrel, they should be instructed in injection techniques to ensure the safe self administration of Enbrel (see instruction sheet supplied with Enbrel). The first injection should be performed under the supervision of a qualified healthcare professional. The ability of that patient to self inject subcutaneously should be assessed. A puncture resistant container for disposal of needles and syringes should be used. Patients should be instructed in the technique and told the importance of proper syringe and needle disposal and be cautioned against reuse of these items.
Disposal. Contains no antimicrobial agent. Product is for single use only in one patient only. Discard any residue.
Missed dose. If a dose is missed, patients should be advised to administer the dose as soon as they remember, unless the next scheduled dose is the next day, in which case the missed dose should be skipped. Patients should continue to inject the medicine on their usual day(s). If a patient does not remember until the day that the next injection is due, instruct the patient not to take a double dose.

4.3 Contraindications

Known hypersensitivity to etanercept or to any of its excipients.
Patients with, or at risk of, sepsis.
Treatment with Enbrel should not be initiated in patients with serious, active infection including chronic or localised infections.
Concurrent treatment with interleukin-1 antagonists.

4.4 Special Warnings and Precautions for Use

Infections.

Patients should be evaluated for infections before, during and after treatment with Enbrel, taking into consideration that the mean elimination half-life of etanercept is 80 hours (standard deviation of 28 hours; range from 7 to 300 hours).
Serious infections including sepsis and tuberculosis, have been reported with the use of Enbrel (see Section 4.8 Adverse Effects (Undesirable Effects)). Some of these infections have been fatal. These infections were due to bacteria, mycobacteria, fungi, viruses and parasites (including protozoa). Opportunistic infections have also been reported (including listeriosis, legionellosis and invasive fungal infections) in patients receiving Enbrel. Many of these serious events have occurred in patients receiving concomitant medicines including immunosuppressants, or with underlying diseases that, in addition to their RA, could predispose them to infections. In some cases, fungal and other opportunistic infections are not recognised and this has resulted in delays in appropriate treatment, sometimes resulting in death. Patients who develop a new infection while undergoing treatment with Enbrel should be monitored closely. Administration of Enbrel should be discontinued if a patient develops a serious infection (e.g. tuberculosis or an atypical mycobacterial infection) or sepsis.
In evaluating patients for infections, physicians should consider the patient's risk for relevant opportunistic infections (e.g. exposure to endemic mycoses). Physicians should exercise caution when considering the use of Enbrel in patients with a history of recurring or chronic infections or with underlying conditions, which may predispose patients to infections such as advanced or poorly controlled diabetes (see Section 4.3 Contraindications). Caution should be exercised in patients at high risk of developing serious infection, including patients undergoing major surgery.

Tuberculosis (TB).

Tuberculosis (including disseminated or extrapulmonary presentation) has been observed in patients receiving TNF blocking agents, including Enbrel. Tuberculosis may be due to reactivation of latent TB infection or to new infection.
Before initiation of therapy with Enbrel, any patient at increased risk for TB should be evaluated for active or latent infection. If active TB is diagnosed, Enbrel therapy must not be initiated. Prophylaxis of latent TB infection should be initiated prior to therapy with Enbrel. Treatment of latent TB in patients with a reactive tuberculin test reduces the risk of TB reactivation in patients receiving TNF blockers.
Some patients who tested negative for latent TB prior to receiving Enbrel have developed active TB. Physicians should monitor patients receiving Enbrel for signs and symptoms of active TB, including patients who tested negative for latent TB infection. Applicable local guidelines should be consulted. Patients with RA appear to have an increased rate of TB infection.
Cases of TB and atypical mycobacterial infections including Mycobacterium avium complex in patients on treatment with Enbrel have been reported. Treatment should be ceased immediately if mycobacterial infection is suspected.
All patients should be informed to seek medical advice if signs/ symptoms suggestive of TB (e.g. persistent cough, wasting/ weight loss, low grade fever) appear during or after Enbrel treatment.

Reactivation of hepatitis B.

Reactivation of hepatitis B in patients who were previously infected with the hepatitis B virus (HBV) and had received TNF blockers, including Enbrel, has been reported. In some instances, HBV reactivation occurring in conjunction with TNF blocker therapy has been fatal. The majority of these reports have occurred in patients concomitantly receiving other medications that suppress the immune system, which may also contribute to HBV reactivation. Patients at risk for HBV infection should be evaluated for evidence of prior HBV infection before initiating TNF blocker therapy. Prescribers should exercise caution in prescribing TNF blockers for patients previously infected with HBV. Patients who were previously infected with HBV and require treatment with TNF blockers should be closely monitored for signs and symptoms of active HBV infection throughout therapy and for several months following termination of therapy. Adequate data are not available on the safety or efficacy of treating patients who are carriers of HBV with antiviral therapy in conjunction with TNF blocker therapy to prevent HBV reactivation. If HBV reactivation should develop in patients who are receiving Enbrel, treatment should be stopped and effective antiviral therapy with appropriate supportive treatment should be initiated.

Worsening of hepatitis C.

There have been reports of worsening of hepatitis C in patients receiving Enbrel, although a causal relationship with Enbrel has not been established.

Alcoholic hepatitis.

In a study of 48 hospitalised patients treated with Enbrel or placebo for moderate to severe alcoholic hepatitis, Enbrel was not efficacious and the mortality rate in patients treated with Enbrel was significantly higher after 6 months. Infections were also higher in the Enbrel group. The use of Enbrel in patients for the treatment of alcoholic hepatitis is not recommended. Physicians should use caution when using Enbrel in patients who also have moderate to severe alcoholic hepatitis.

Hypoglycaemia in patients treated for diabetes.

There have been reports of hypoglycaemia following initiation of Enbrel in patients receiving medication for diabetes, necessitating a reduction in antidiabetic medication in some of these patients.

Inflammatory bowel disease (IBD) and uveitis.

There have been reports of IBD and uveitis in patients being treated with Enbrel, which is not indicated for the treatment of IBD. A causal relationship between IBD and Enbrel cannot be excluded (see Section 4.8 Adverse Effects (Undesirable Effects)).

Concurrent administration of TNF inhibitors and anakinra.

Concurrent administration of Enbrel and anakinra (a recombinant, non-glycosylated form of the human interleukin-1 receptor antagonist) has been associated with an increased risk of serious infection, an increased risk of neutropenia and no additional benefit compared to Enbrel alone. The safety and efficacy of anakinra used in combination with Enbrel has not been established. Therefore, combination of Enbrel and anakinra is contraindicated (also see Section 4.3 Contraindications; Section 4.5 Interactions with Other Medicines and Other Forms of Interactions).

Concurrent administration of Enbrel and abatacept.

In clinical studies, concurrent administration of abatacept and Enbrel therapy resulted in increased incidences of serious adverse events, including infections. This combination has not demonstrated increased clinical benefit; such use is not recommended (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions).

Interstitial lung disease.

There have been post-marketing reports of interstitial lung disease (including pneumonitis and pulmonary fibrosis), some of which had fatal outcomes.

Haematological reactions.

Rare cases of pancytopenia and very rare cases of aplastic anaemia, some with fatal outcome, have been reported in patients treated with Enbrel. Caution should be exercised in patients being treated with Enbrel who have a previous history of blood dyscrasias. All patients should be advised that if they develop signs and symptoms suggestive of blood dyscrasias or infections (e.g. persistent fever, sore throat, bruising, bleeding, paleness) whilst on Enbrel, they should seek immediate medical advice. Such patients should be evaluated urgently, including full blood count; if any blood dyscrasias are confirmed, Enbrel should be discontinued.

Allergic reactions.

Parenteral administration of any biological product should be attended by appropriate precautions in case an allergic or untoward reaction occurs. Allergic reactions associated with Enbrel administration have been reported commonly. Allergic reactions have included angioedema and urticaria. Serious reactions have occurred (see Section 4.8 Adverse Effects (Undesirable Effects)). If any serious allergic or anaphylactic reaction occurs, Enbrel therapy should be discontinued immediately and appropriate therapy initiated.
Latex (dry natural rubber) is present in the rubber closure of the diluent syringe (vial presentation), in the needle cover of both the prefilled syringe and dose-dispenser cartridge presentations, and also in the needle cap of the auto-injector presentation. This may cause hypersensitivity reactions when handled by, or when Enbrel is administered to, persons with known or possible latex sensitivity. Patients or caregivers should contact their doctor before using Enbrel if these latex components will be handled by, or if Enbrel will be given to, someone with a known hypersensitivity to latex.

Congestive heart failure.

There have been post-marketing reports of worsening of congestive heart failure (CHF), with and without identifiable precipitating factors, in patients taking Enbrel. There have also been rare (< 0.1%) reports of new onset CHF, including CHF in patients without known pre-existing cardiovascular disease. Some of these patients have been under 50 years of age. Two large clinical trials evaluating the use of Enbrel in the treatment of CHF were terminated early due to lack of efficacy. Although not conclusive, data from one of these trials suggests a possible tendency towards worsening CHF and higher mortality in those patients assigned to Enbrel treatment. Physicians should use caution when using Enbrel in patients who also have CHF and monitor patients carefully.

Neurological disorders.

Although no clinical trials have been performed evaluating Enbrel therapy in patients with multiple sclerosis, clinical trials of other TNF antagonists in patients with multiple sclerosis have shown increases in disease activity. Treatment with Enbrel and other agents that inhibit TNF have been associated with rare cases of new onset or exacerbation of central nervous system demyelinating disorders, some presenting with mental status changes and some associated with permanent disability. Cases of transverse myelitis, optic neuritis, multiple sclerosis, and new onset or exacerbation of seizure disorders have been observed in association with Enbrel therapy (see Section 4.8 Adverse Effects (Undesirable Effects)). Additionally, there have been very rare reports of peripheral demyelinating polyneuropathies (including Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, demyelinating polyneuropathy, and multifocal motor neuropathy). A careful risk/ benefit evaluation, including a neurological assessment, is recommended when prescribing Enbrel therapy to patients with pre-existing or recent onset of central nervous system (CNS) demyelinating disease, or to those who are considered to have an increased risk of developing demyelinating disease.

Use in psoriasis.

There are limited data on the use of Enbrel in combination with methotrexate for the treatment of psoriasis. The safety and efficacy of this combination in psoriasis have not been established.
The safety and efficacy of Enbrel in combination with other immunosuppressive agents used in psoriasis or with phototherapy have not been studied. Enbrel should not be used in combination with such agents because of the possibility of excessive immunosuppression.

Monitoring.

Based on the results of clinical studies in rheumatoid arthritis, normally no special laboratory evaluations are necessary in addition to careful medical management and supervision of patients.

Malignancies.

Lymphomas.

TNF modulates immune responses and has a protective effect against the development of some tumours. The impact of treatment with Enbrel on the course of development of malignancies, including those caused by immunosuppressive agents, is not understood and has not been studied. The possibility exists for antitumour necrosis factor (TNF) therapies, including Enbrel, to affect host defences against infections and malignancies, since TNF mediates inflammation and modulates cellular immune responses. The impact of treatment with Enbrel on the development and course of malignancies and active and/or chronic infections is not fully understood (see Section 4.8 Adverse Effects (Undesirable Effects)). Reports of malignancies affecting various sites have been received in the post-marketing period including breast and lung carcinoma and lymphoma.
In the controlled portions of clinical trials of all the TNF blocking agents, more cases of lymphoma have been observed among patients receiving the TNF blocker compared to control patients. During the controlled portions of Enbrel trials, 3 lymphomas were observed among 4,509 Enbrel treated patients versus 0 among 2,040 control patients (duration of controlled treatment ranged from 3 to 24 months).
Among 6,543 adult rheumatology (RA, PsA, AS) patients treated with Enbrel in controlled and uncontrolled portions of clinical trials representing approximately 12,845 patient years of therapy, the observed rate of lymphoma was 0.10 cases per 100 patient years. This was 3-fold higher than the rate of lymphoma expected in the general U.S. population based on the Surveillance, Epidemiology, and End Results (SEER) database. While patients with rheumatoid arthritis or psoriasis, particularly those with highly active disease, may be at a higher risk (up to several fold) for the development of lymphoma, a possible risk for the development of lymphomas or other malignancies in patients treated with a TNF antagonist cannot be excluded.
Among 4,410 adult PsO patients treated with Enbrel in clinical trials up to 36 months, representing approximately 4,278 patient years of therapy, the observed rate of lymphoma was 0.05 cases per 100 patient years, which is comparable to the rate in the general population. No cases were observed in Enbrel or placebo treated patients during the controlled portions of these trials.

Leukaemia.

Cases of acute and chronic leukaemia have been reported in association with post-marketing TNF blocker use in rheumatoid arthritis and other indications. Even in the absence of TNF blocker therapy, patients with rheumatoid arthritis may be at higher risk (approximately 2-fold) than the general population for the development of leukaemia.
During the controlled portions of Enbrel trials, 2 cases of leukaemia were observed among 5,445 (0.06 cases per 100 patient years) Enbrel treated patients versus 0 among 2,890 control patients (duration of controlled treatment ranged from 3 to 48 months).
Among 15,401 patients treated with Enbrel in controlled and open portions of clinical trials representing approximately 23,325 patient years of therapy, the observed rate of leukaemia was 0.03 cases per 100 patient years.

Other malignancies.

Information is available from 10,953 adult patients with 17,123 patient years and 696 paediatric patients with 1,282 patient years of experience across 45 Enbrel clinical studies.
For malignancies other than lymphoma and nonmelanoma skin cancer, there was no difference in exposure adjusted rates between the Enbrel and control arms in the controlled portions of clinical studies for all indications. Analysis of the malignancy rate in combined controlled and uncontrolled portions of studies has demonstrated that types and rates are similar to what is expected in the general U.S. population based on the SEER database and suggests no increase in rates over time. Whether treatment with Enbrel might influence the development and course of malignancies in adults is unknown.

Wegener's granulomatosis.

In a placebo-controlled study of 180 patients with Wegener's granulomatosis, the addition of Enbrel to standard treatment (including cyclophosphamide and high dose steroids) was no more efficacious than standard treatment alone. The group of patients who received Enbrel experienced more noncutaneous malignancies of various types than the patient group receiving standard treatment alone. The use of Enbrel for treatment of Wegener's granulomatosis is not recommended.

Melanoma and nonmelanoma skin cancer.

Melanoma and nonmelanoma skin cancer (NMSC) have been reported in patients treated with TNF antagonists, including Enbrel. Post-marketing cases of Merkel cell carcinoma have been reported very infrequently in patients treated with Enbrel. Periodic skin examination is recommended for all patients who are at increased risk for skin cancer. Combining the results of controlled portions of clinical trials of Enbrel, more cases of nonmelanoma skin cancer were observed in patients taking Enbrel compared with control patients, particularly in patients with psoriasis.
Among 3,306 adult rheumatology (RA, PsA, AS) patients treated with Enbrel in controlled clinical trials representing approximately 2,669 patient years of therapy, the observed rate of NMSC was 0.41 cases per 100 patient years vs 0.37 cases per 100 patient years among 1,521 control treated patients representing 1,077 patient years. Among 1,245 adult psoriasis patients treated with Enbrel in controlled clinical trials, representing approximately 283 patient years of therapy, the observed rate of NMSC was 3.54 cases per 100 patient years vs 1.28 cases per 100 patient years among 720 control treated patients representing 156 patient years.
Among 15,401 patients treated with Enbrel in controlled and open portions of clinical trials representing approximately 23,325 patient years of therapy, the observed rate of melanoma was 0.043 cases per 100 patient years.

Immunosuppression.

In a study of 49 patients with RA treated with Enbrel, there was no evidence of depression of delayed type hypersensitivity, depression of immunoglobulin levels, or change in enumeration of effector cell populations. The safety and efficacy of Enbrel, in patients with immunosuppression or chronic infections have not been evaluated.

Vaccinations.

Most psoriatic patients receiving Enbrel were able to mount an effective B-cell immune response to pneumococcal polysaccharide vaccine, but titers in aggregate were moderately lower and fewer patients had two-fold rises in titers compared to patients not receiving Enbrel. Live vaccines should not be given concurrently with Enbrel (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions). No data are available on the secondary transmission of infection by live vaccines in patients receiving Enbrel. If possible, bring paediatric patients up to date with all immunisations (including varicella) in agreement with current immunisation guidelines prior to initiating Enbrel therapy. Patients with a significant exposure to varicella virus should temporarily discontinue Enbrel therapy and be considered for prophylactic treatment with varicella zoster immune globulin.

Autoantibody formation.

Treatment with Enbrel may result in the formation of autoimmune antibodies (see Section 4.8 Adverse Effects (Undesirable Effects)). Rare reports have been described in clinical trials and post-marketing experience of autoimmune hepatitis, a lupus-like syndrome or rashes compatible with subacute cutaneous lupus or discoid lupus. If a patient develops symptoms and findings suggestive of autoimmune hepatitis or a lupus-like syndrome, treatment should be discontinued and the patient carefully evaluated.

Paediatric use.

Enbrel has not been studied in children less than 2 years of age.
Studies have not been done in patients with juvenile idiopathic arthritis (JIA) to assess the effects of continued Enbrel therapy in patients who do not respond within 3 months of initiating Enbrel therapy. Additionally, studies have not been conducted to assess the effects of discontinuing or reducing the recommended dose of Enbrel following its long-term use in patients with JIA.
Malignancies, some fatal, have been reported among children, adolescents and young adults who received treatment with TNF blocking agents (initiation of therapy at ≤ 18 years of age), including Enbrel to treat JIA and other indications. Approximately half of the cases were lymphomas, including Hodgkin's and non-Hodgkin's lymphoma. The other cases represented a variety of different malignancies and included rare malignancies that are not usually observed in children and adolescents. The malignancies occurred after a median of 30 months of therapy (range 1 to 84 months). Most of the patients were receiving concomitant immunosuppressants. These cases were derived from several sources including registries and post-marketing reports. In addition, there was one case of lymphoma reported in paediatric clinical trials.
Two JIA patients developed varicella infection and signs and symptoms of aseptic meningitis, which resolved without sequelae. Patients with a significant exposure to varicella virus should temporarily discontinue Enbrel therapy and be considered for prophylactic treatment with varicella zoster immune globulin.
There have been reports of inflammatory bowel disease and uveitis in patients with JIA (see Section 4.4 Special Warnings and Precautions for Use, Inflammatory bowel disease (IBD) and uveitis in patients with juvenile idiopathic arthritis (JIA)).
The long-term effects of Enbrel on the growth and development of children are not known.

Use in the elderly.

A total of 480 RA patients aged 65 years or older have been studied in clinical trials. In PsO randomised clinical trials, a total of 138 out of 1,965 patients treated with Enbrel or placebo were age 65 or older. No overall differences in safety or effectiveness were observed between these patients and younger patients, but the number of geriatric PsO patients is too small to determine whether they respond differently from younger patients. The clinical trial in nonradiographic axial spondyloarthritis did not include patients aged 50 years or older. Greater sensitivity of some older individuals cannot be ruled out. Because there is a higher incidence of infections in the elderly population in general, caution should be used in treating the elderly.

Effects on laboratory tests.

No effects on laboratory tests have been reported in adults. An analysis of 54 JIA patients in an open label study demonstrated low haemoglobin, low albumin and low lymphocyte counts in 63%, 39% and 30% of juvenile patients, respectively. These observations, however, appear to be attributed to the underlying disease, rather than treatment with Enbrel.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Methotrexate.

Enbrel may be administered in combination with methotrexate for the treatment of rheumatoid arthritis. In a safety and efficacy trial, methotrexate had no effect on the pharmacokinetics of Enbrel. The effect of Enbrel on the pharmacokinetics of methotrexate has not been investigated. Product information for methotrexate should be consulted when Enbrel is administered with methotrexate.

Abatacept.

In clinical studies, concurrent administration of abatacept and Enbrel resulted in increased incidences of serious adverse events, including infections, and did not demonstrate increased clinical benefit. Use of Enbrel with abatacept is not recommended.

Anakinra.

Patients treated with Enbrel and anakinra were observed to have a higher rate of serious infection (7%) when compared with patients who were treated with Enbrel alone (0%, historical data). In addition, in a double blind placebo-controlled trial, in patients receiving background methotrexate, patients treated with Enbrel and anakinra were observed to have a higher rate of serious infection and neutropenia than patients who were treated with Enbrel alone (see Section 4.4 Special Warnings and Precautions for Use).

Cyclophosphamide.

The use of Enbrel in patients receiving concurrent cyclophosphamide therapy is not recommended (see Section 4.4 Special Warnings and Precautions for Use, Wegener's granulomatosis).

Live vaccines.

No safety data are available on the effects of live vaccine when used in combination with Enbrel. Live vaccines should, therefore, not be given concurrently with Enbrel.

Sulfasalazine.

In a clinical study of patients who were receiving established doses of sulfasalazine, to which Enbrel was added, patients in the combination group experienced a statistically significant decrease in mean white blood cell counts in comparison to groups treated with Enbrel or sulfasalazine alone.

Digoxin.

Enbrel does not significantly affect digoxin exposure. There was a reduction in Enbrel exposure in the presence of digoxin, however, there was significant intersubject variability. The clinical significance of this reduced exposure is uncertain (see Table 1).

Warfarin.

Enbrel does not significantly affect warfarin exposure. There was a slight reduction in Enbrel exposure in the presence of warfarin, however, there was significant intersubject variability. The clinical significance of this reduced exposure is uncertain (see Table 2).

Other.

In clinical trials, no apparent interactions have been observed when Enbrel was administered with glucocorticoids, salicylates (except sulfasalazine, see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions, Sulfasalazine), nonsteroidal anti-inflammatory drugs (NSAIDs) or analgesics.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

Long-term animal studies have not been conducted to evaluate the effects of Enbrel on fertility.
(Category D)
Women of childbearing potential should consider the use of appropriate contraception to avoid becoming pregnant during Enbrel therapy and for three weeks after discontinuation of therapy.
The safe use of Enbrel during pregnancy has not been established. Enbrel should only be used during pregnancy if the potential benefits to the mother outweigh the potential risks to the fetus. If Enbrel is used during pregnancy, or if the patient becomes pregnant while taking it, the woman should be advised of the possible risk to the fetus.
Developmental toxicity studies have been performed in rats and rabbits at doses resulting in AUC based systemic exposure levels of etanercept that were at least 12-fold higher than in humans at the highest proposed therapeutic dose of 50 mg and have revealed no evidence of harm to the fetus due to Enbrel. There are, however, no studies in pregnant women. Animal studies are not always predictive of human response.
Etanercept crosses the placenta and has been detected in the serum of infants born to female patients treated with Enbrel during pregnancy. The clinical impact of this is unknown, however, infants may be at increased risk of infection. Administration of live vaccines to infants for 16 weeks after the mother's last dose of Enbrel is generally not recommended.
The effects of etanercept on pregnancy outcomes have been investigated in two observational cohort studies. One pregnancy registry examined the risk of major birth defects and other pregnancy outcomes in mothers with rheumatic diseases or psoriasis exposed to Enbrel in the first trimester (n = 319) versus those who were unexposed to Enbrel or other TNF antagonists (n = 144). The all inclusive odds ratio for major birth defects in those exposed to Enbrel was 2.77 (95% CI 1.04-7.35) compared to nonexposed mothers with inflammatory disease. The findings showed no clear pattern of major or minor malformations. There was no increase in rates of intrauterine or postnatal growth deficits or delayed postnatal development.
In a second observational multi-country registry study comparing the risk of adverse pregnancy outcomes in women exposed to etanercept (n = 522) to those exposed to non-biologic drugs (n = 3508), there was no observed increased risk of major birth defects (adjusted odds ratio 0.96, 95% CI: 0.58-1.60). This study also showed no increased risks of minor birth defects, preterm birth, stillbirth or infections in the first year of life for infants born to women exposed to etanercept during pregnancy.
 In lactating rats, following subcutaneous administration etanercept was detected in the serum of the pups. Limited information from the published literature indicates etanercept has been detected at low levels in human milk. Use of etanercept during breastfeeding should be assessed taking into account the risks and benefits of breastfeeding for the child and therapy for the mother.
While systemic exposure in a breastfed infant is expected to be low because etanercept is largely degraded in the gastrointestinal tract, limited data regarding systemic exposure in the breastfed infant are available. Therefore, the administration of live vaccines (e.g. BCG) to a breastfed infant when the mother is receiving etanercept could be considered 16 weeks after stopping breastfeeding (or at an earlier timepoint if the infant etanercept serum levels are undetectable).

4.7 Effects on Ability to Drive and Use Machines

No studies on the effects on the ability to drive and use machines have been performed.

4.8 Adverse Effects (Undesirable Effects)

Injection site reactions.

Patients with rheumatic diseases in controlled trials treated with Enbrel had a significantly higher incidence (37% cf.10%) of injection site reactions (erythema and/or itching, pain, bleeding, bruising or swelling) compared with placebo treated patients, and generally did not necessitate drug discontinuation. The frequency of injection site reactions was greatest in the first month and subsequently decreased in frequency. Mean duration was 3 to 5 days. No treatment was given for the majority of injection site reactions in the Enbrel treatment groups, and the majority of those patients who were given treatment received topical preparations such as corticosteroids, or oral antihistamines. Some patients who experienced injection site reactions also experienced reactions at previous injection sites. In post-marketing experience, injection site bleeding and bruising have also been observed in conjunction with Enbrel therapy.
In controlled trials in patients with plaque psoriasis, approximately 13.6% of patients treated with Enbrel developed injection site reactions compared with 3.4% of placebo treated patients during the first 12 weeks of treatment.

Infections.

In placebo-controlled trials, no increase in the incidence of serious infections (fatal, life threatening, or requiring hospitalisation or intravenous antibiotics) was observed. Serious infections occurred in 6.3% of rheumatoid arthritis patients treated with Enbrel for up to 48 months. These included abscess (at various sites), bacteraemia, bronchitis, bursitis, cellulitis, cholecystitis, diarrhoea, diverticulitis, endocarditis (suspected), gastroenteritis, hepatitis B, herpes zoster, leg ulcer, mouth infection, osteomyelitis, otitis, peritonitis, pneumonia, pyelonephritis, sepsis, septic arthritis, sinusitis, skin infection, skin ulcer, urinary tract infection, vasculitis, and wound infection. In the 2 year active-controlled study where patients were treated with either Enbrel alone, methotrexate alone or Enbrel in combination with methotrexate, the rates of serious infections were similar among the treatment groups. However, it cannot be excluded that the combination of Enbrel with methotrexate could be associated with an increase in the rate of infections.
There were no differences in rates of infection among patients treated with Enbrel and those treated with placebo for plaque psoriasis in placebo-controlled trials of up to 24 weeks duration. Serious infections experienced by Enbrel treated patients included cellulitis, gastroenteritis, pneumonia, cholecystitis, osteomyelitis, gastritis, appendicitis, Streptococcal fasciitis, myositis, septic shock, diverticulitis and abscess. In the double blind and open label psoriatic arthritis trials, 1 patient reported a serious infection (pneumonia).
Serious and fatal infections have been reported during use of Enbrel; reported pathogens include bacteria, mycobacteria (including tuberculosis), viruses and fungi. Some infections have occurred within a few weeks after initiating treatment with Enbrel in patients who have underlying conditions (e.g. diabetes, congestive heart failure, history of active or chronic infections) in addition to their rheumatoid arthritis Enbrel treatment may increase mortality in patients with established sepsis.
Opportunistic infections have been reported in association with Enbrel, including invasive fungal, parasitic (including protozoal), viral (including herpes zoster), bacterial (including Listeria and Legionella), and atypical mycobacterial infections (see Section 4.4 Special Warnings and Precautions for Use). In a pooled data set of clinical trials, the overall incidence of opportunistic infections was 0.09% for the 15,402 subjects who received Enbrel. The exposure adjusted rate was 0.06 events per 100 patient years. In post-marketing experience, approximately half of all of the case reports of opportunistic infections worldwide were invasive fungal infections. The most commonly reported invasive fungal infections included Candida, Pneumocystis, Aspergillus and Histoplasma. Invasive fungal infections accounted for more than half of the fatalities amongst patients who developed opportunistic infections. The majority of the reports with a fatal outcome were in patients with Pneumocystis pneumonia, unspecified systemic fungal infections, and aspergillosis.

Malignancies and lymphoproliferative disorders.

Reports of malignancies affecting various sites have been received in the post-marketing period. The observed rates and incidences of new malignancies in clinical trials with Enbrel were similar to those expected for the population studied. Patients have been observed in clinical trials with Enbrel for over five years. Among 4,462 rheumatoid arthritis patients treated with Enbrel in clinical trials for a mean of 27 months (approximately 10,000 patient years of therapy), 9 lymphomas were observed for a rate of 0.09 cases per 100 patient years. This is 3-fold higher than the rate of lymphomas expected in the general population based on the Surveillance, Epidemiology and End Results Database. An increased rate of lymphoma up to several fold has been reported in the rheumatoid arthritis patient population and may be further increased in patients with more severe disease activity (see Section 5.3 Preclinical Safety Data, Carcinogenicity).
There have been reports of malignancies in a clinical trial of patients being treated for Wegener's granulomatosis (see Section 4.4 Special Warnings and Precautions for Use, Malignancies).

Interstitial lung disease.

In controlled clinical trials of etanercept across all indications, the frequency (incidence proportion) of interstitial lung disease in patients receiving etanercept without concomitant methotrexate was rare. In the controlled clinical trials that allowed concomitant treatment with etanercept and methotrexate, the frequency (incidence proportion) of interstitial lung disease was uncommon. There have been post-marketing reports of interstitial lung disease (including pneumonitis and pulmonary fibrosis), some of which had fatal outcomes.

Elevated liver enzymes.

In the double-blind periods of controlled clinical trials of etanercept across all indications, the frequency (incidence proportion) of adverse events of elevated liver enzymes in patients receiving etanercept without concomitant methotrexate was uncommon. In the double-blind periods of controlled clinical trials that allowed concomitant treatment with etanercept and methotrexate, the frequency (incidence proportion) of adverse events of elevated liver enzymes was common.

Autoimmune hepatitis.

In controlled clinical trials of etanercept across all indications, the frequency (incidence proportion) of autoimmune hepatitis in patients receiving etanercept without concomitant methotrexate was rare. In the controlled clinical trials that allowed concomitant treatment with etanercept and methotrexate, the frequency (incidence proportion) of autoimmune hepatitis was uncommon.

Autoantibody formation.

In controlled trials, the percentage of patients who developed new positive antinuclear antibodies (ANA) (≥ 1:40), new positive antidouble stranded DNA antibodies and new anticardiolipin antibodies were increased compared to placebo treated patients (11% cf. 5% respectively). The percentage of patients who developed new positive antidouble stranded DNA antibodies was also higher by radioimmunoassay (15% of patients treated with Enbrel compared to 4% of placebo treated patients) and by Crithidia luciliae assay (3% of patients treated with Enbrel compared to none of placebo treated patients). The proportion of patients treated with Enbrel who developed anticardiolipin antibodies was similarly increased compared to placebo treated patients.
Rare reports have been described in clinical trials and post-marketing experience, including patients with rheumatoid factor positive RA, who have developed additional antibodies in conjunction with autoimmune hepatitis, a lupus-like syndrome or rashes compatible with subacute cutaneous lupus or discoid lupus by clinical presentation and biopsy (see Section 4.8 Adverse Effects (Undesirable Effects), Other adverse reactions). The impact of long-term treatment with Enbrel on the development of autoimmune diseases is unknown. If a patient develops symptoms and findings suggestive of a lupus-like syndrome or autoimmune hepatitis following treatment with Enbrel, treatment should be discontinued and the patient should be carefully evaluated.

Psoriasis.

Cases of new onset psoriasis, including pustular psoriasis and palmoplantar psoriasis, and cases of exacerbation of pre-existing psoriasis have been reported with the use of TNF blockers, including Enbrel. Many of these patients were taking concomitant immunosuppressants (e.g. methotrexate, corticosteroids). Some of these patients required hospitalisation. Most patients had improvements of their psoriasis following discontinuation of their TNF blocker. Some patients have had recurrences of the psoriasis when they were rechallenged with a different TNF blocker. Discontinuation of Enbrel should be considered for severe cases and those that do not improve or that worsen despite topical treatments.

Other adverse reactions.

Events reported in at least 3% of all patients with higher incidence in patients treated with Enbrel compared to controls in placebo-controlled RA trials (including the combination methotrexate trial) and events per patient year are summarised in Table 3.
Based on the results of clinical studies in rheumatoid arthritis, normally no special laboratory evaluations are necessary in addition to careful medical management and supervision of patients.
The following table of suspected adverse reactions is based on clinical trials and/or spontaneous post-marketing reports.
Adverse reaction frequencies are listed in Table 4 in CIOMS frequency categories: very common: ≥ 10%; common: ≥ 1% and < 10%; uncommon: ≥ 0.1% and < 1%; rare: ≥ 0.01% and < 0.1%; very rare: < 0.01%.

Patients with nonradiographic axial spondyloarthritis.

The safety observed in adult patients with nr-AxSpA was similar to that seen in previous clinical trials of etanercept in adult patients.

Paediatric patients with juvenile idiopathic arthritis.

In general, the adverse events in paediatric patients with juvenile idiopathic arthritis were similar in frequency and type to those seen in adult patients.
JIA patients treated with Enbrel had a significantly higher incidence of injection sites reactions (erythema and/or itching, pain or swelling) compared with placebo treated patients in controlled clinical trials.
Infection was the most common adverse event reported in paediatric patients taking Enbrel and occurred at an incidence similar to placebo. The types of infections reported in JIA patients were generally mild and consistent with those commonly seen in outpatient paediatric populations.
In JIA clinical trials, two cases of varicella infection with signs and symptoms suggestive of aseptic meningitis have been reported among patients treated with Enbrel. There were also 4 reports of macrophage activation syndrome.
Long-term safety of Enbrel monotherapy (n = 103), Enbrel plus methotrexate (n = 294), or methotrexate monotherapy (n = 197) were assessed for up to 3 years in a registry of 594 children aged 2 to 18 years with juvenile idiopathic arthritis, 39 of whom were 2 to 3 years of age. Overall, infections were more commonly reported in patients treated with Enbrel compared to methotrexate alone (3.8% versus 2%), and the infections associated with Enbrel use were of a more severe nature.

Paediatric patients with plaque psoriasis.

In a 48 week study in 211 children aged 4 to 17 years with paediatric plaque psoriasis, the adverse events reported were similar to those seen in previous studies in adults with plaque psoriasis.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems.

4.9 Overdose

The maximum tolerated dose of Enbrel has not been established in humans. Repeat dose studies have been performed in cynomolgus monkeys at doses resulting in AUC based systemic exposure levels of etanercept that were over 13-fold higher than in humans at the highest proposed therapeutic dose of 50 mg and have revealed no dose limiting or target organ toxicity. No dose limiting toxicities were observed during clinical trials of RA patients. The highest dose level evaluated has been an IV loading dose of 32 mg/m2 followed by SC doses of 16 mg/m2 administered twice weekly. One RA patient mistakenly self administered 62 mg Enbrel SC twice weekly for three weeks without experiencing unexpected side effects. Single IV doses up to 60 mg/m2 (approximately twice the recommended dose) have been administered to healthy volunteers in an endotoxaemia study without evidence of dose limiting toxicities.
There is no known antidote to Enbrel. For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Pharmacodynamics.

Etanercept binds specifically to tumour necrosis factor (TNF) and blocks its interaction with cell surface TNF receptors. Etanercept did not induce complement mediated cytolysis of murine T cells that expressed TNF on the cell surface. TNF is a naturally occurring cytokine that is involved in normal inflammatory and immune responses. TNF is a dominant cytokine in the inflammatory process of rheumatoid arthritis. Elevated levels of TNF are also found in the synovium and psoriatic plaques of patients with psoriatic arthritis and in serum and synovial tissue of patients with ankylosing spondylitis. In plaque psoriasis, infiltration by inflammatory cells including T cells leads to increased TNF levels in psoriatic lesions, compared with levels in uninvolved skin.
Two distinct receptors for TNF (TNFRs), a 55 kilodalton protein (p55) and a 75 kilodalton protein (p75), exist naturally as monomeric molecules on cell surfaces and in soluble forms. Biological activity of TNF is dependent upon binding to either cell surface TNFR.
Etanercept is a dimeric soluble form of the p75 TNF receptor that can bind to two TNF molecules. It inhibits the activity of TNF in vitro and has been shown to affect several animal models of inflammation, including murine collagen induced arthritis. Etanercept inhibits binding of both TNFα and TNFβ (lymphotoxin alpha [LTα]) to cell surface TNFRs, rendering TNF biologically inactive. Cells expressing transmembrane TNF that bind Enbrel are not lysed in vitro in the presence or absence of complement.
The potency is determined by measuring the ability of etanercept to neutralise the TNFα-mediated growth inhibition of A375 cells. The specific activity of etanercept is 1.7 x 106 units/mg.

Mechanism of action.

Proinflammatory molecules that are linked in a network controlled by TNF mediate much of the joint pathology in rheumatoid arthritis and ankylosing spondylitis and skin pathology in plaque psoriasis. The mechanism of action of etanercept is thought to be its competitive inhibition of TNF binding to cell surface TNFR, preventing TNF mediated cellular responses by rendering TNF biologically inactive. Etanercept may also modulate biological responses controlled by additional downstream molecules (e.g. cytokines, adhesion molecules, or proteinases) that are induced or regulated by TNF.

Clinical trials.

This section presents data from 5 randomised controlled studies in adults with rheumatoid arthritis, 3 studies in paediatric patients with JIA, 2 studies in adults with ankylosing spondylitis, 2 studies in adults with nonradiographic axial spondyloarthritis, 1 study in adults with psoriatic arthritis, 2 studies in adults with plaque psoriasis and 1 study in paediatric patients with plaque psoriasis.
Adult rheumatoid arthritis.

Placebo-controlled studies.

The efficacy of Enbrel was assessed in a randomised, double blind, placebo-controlled study. The study evaluated 234 adult patients with active rheumatoid arthritis who had failed therapy with at least one but no more than four disease modifying antirheumatic drugs (DMARDs). Doses of 10 mg or 25 mg Enbrel or placebo were administered subcutaneously twice a week for 6 consecutive months. The results of this controlled trial were expressed in percentage improvement in rheumatoid arthritis using American College of Rheumatology (ACR) response criteria. The primary endpoint was achievement of an ACR 20 response at month 3. Subjects who failed to respond based on prespecified criteria for lack of efficacy before month 3 were allowed to drop out early and were considered treatment failures. ACR 20 and 50 responses were higher in patients treated with Enbrel at 3 and 6 months than in patients treated with placebo at all time points as seen in Table 5.
Approximately 15% of subjects who received Enbrel achieved an ACR 70 response at month 3 and month 6, compared to fewer than 5% of subjects in the placebo arm. Among patients receiving Enbrel, the clinical responses generally appeared within 1 to 2 weeks after initiation of therapy and nearly always occurred by 3 months. A dose response was seen; results with 10 mg were intermediate between placebo and 25 mg. Enbrel was significantly better than placebo in all components of the ACR criteria as well as other measures of rheumatoid arthritis disease activity not included in the ACR response criteria, such as morning stiffness. A Health Assessment Questionnaire (HAQ), which included disability, vitality, mental health, general health status and arthritis associated health status subdomains, was administered every 3 months during the trial. All subdomains of the HAQ were improved in patients treated with Enbrel compared to controls at 3 and 6 months.
After discontinuation of Enbrel, symptoms of arthritis generally returned within a month. Reintroduction of treatment with Enbrel after discontinuations of up to 24 months resulted in the same magnitudes of response as patients who received Enbrel without interruption of therapy based on results of open label studies. Continued durable responses have been seen in open label extension treatment trials when patients received Enbrel without interruption.
A second randomised, double blind, placebo-controlled study also compared the safety and efficacy of Enbrel (25 mg) against placebo (SC, twice a week over 6 months) in 89 RA patients in addition to a stable dose of methotrexate. The ACR response criteria were used to assess efficacy. The primary endpoint was achievement of an ACR 20 response at 6 months. Responses were higher in patients treated with Enbrel at 3 and 6 months. Clinical responses in Enbrel treated patients generally appeared after 1-2 weeks of therapy. In addition, approximately 15% of Enbrel treated patients achieved an ACR 70 response at month 3 and month 6, compared to less than 5% of subjects in the placebo arm. Enbrel treated patients experienced significantly greater improvements in all components of the ACR criteria, compared to patients in the placebo arm.
The safety and efficacy of 50 mg Enbrel (two 25 mg SC injections) administered once weekly were evaluated in a double blind, placebo-controlled study of 420 patients with active RA. In this study, 53 patients received placebo, 214 patients received 50 mg Enbrel once weekly and 153 patients received 25 mg Enbrel twice weekly. The safety and efficacy profiles of the two Enbrel treatment regimens were comparable in their effect on signs and symptoms of RA.

Active-controlled studies.

A randomised, active-controlled study with blinded radiographic evaluations as a primary endpoint compared the efficacy of Enbrel to oral methotrexate in 632 adult patients with active rheumatoid arthritis (< 3 years duration) who had never received treatment with methotrexate. The patients had to have > 12 tender joints, > 10 swollen joints and either ESR > 28 mm/hr, CRP > 2.0 mg/dL, or morning stiffness for > 45 minutes. Patients were at high risk of erosive disease defined as being rheumatoid factor positive or having at least three erosions at baseline. Doses of 10 mg or 25 mg Enbrel were administered SC twice a week for up to 24 months. Methotrexate doses were escalated from 7.5 mg/week to a maximum of 20 mg/week over the first 8 weeks of the trial and continued for up to 24 months. Clinical improvement including onset of action within 2 weeks with Enbrel 25 mg was similar to that seen in the previous 2 trials and was maintained for up to 24 months. At baseline, patients had a moderate degree of disability, with mean HAQ scores of 1.4 to 1.5. Treatment with Enbrel 25 mg resulted in substantial improvement at 12 months, with about 44% of patients achieving a normal HAQ score (less than 0.5). This benefit was maintained in year 2 of this study.
In this study, structural joint damage was assessed radiographically and expressed as change in Total Sharp Score (TSS) and its components, the erosion score and joint space narrowing score (JSN). Radiographs of hands/ wrists and feet were read at baseline and 6, 12 and 24 months. The 10 mg Enbrel dose had consistently less effect on structural damage than the 25 mg dose. Enbrel 25 mg was significantly superior to methotrexate for erosion scores at both 12 and 24 months. The differences in TSS and JSN were not statistically significant between methotrexate and Enbrel 25 mg. The results are shown in Figure 1.
In another active-controlled, double blind, randomised study, clinical efficacy, safety and radiographic progression in RA patients treated with Enbrel alone (25 mg twice weekly), methotrexate alone (7.5 to 20 mg weekly, median dose 20 mg) and of the combination of Enbrel and methotrexate initiated concurrently were compared in 682 adult patients with active rheumatoid arthritis of 6 months to 20 years duration (median 5 years) who had a less than satisfactory response to at least 1 DMARD other than methotrexate. Forty-three percent of patients had previously received methotrexate a mean of 2 years prior to the trial at a mean dose of 12.9 mg/week. Patients were excluded from this study if methotrexate had been discontinued for lack of efficacy or for safety considerations.
Patients in the Enbrel in combination with methotrexate therapy group had significantly higher ACR 20, ACR 50, ACR 70 responses and improvement for disease activity scores (DAS) at both 24 and 52 weeks than patients in either of the single therapy groups (results shown in Table 6).
The percentage of patients who achieved low disease activity (defined as DAS < 2.4) at 52 weeks was 39%, 35% and 61% for patients in the Enbrel alone group, methotrexate alone group and the Enbrel combination group, respectively. Remission (defined as DAS < 1.6) was experienced by 18%, 14% and 37% of patients administered Enbrel alone, methotrexate alone and combination therapy, respectively.
Mean HAQ scores improved from baseline levels of (1.7, 1.7 and 1.8) to (1.0, 1.1 and 0.8) at 52 weeks in the Enbrel, methotrexate and Enbrel in combination with methotrexate treatment groups, respectively (combination versus both methotrexate and Enbrel, p < 0.01).
Radiographic progression as measured by Total Sharp Score (TSS) was significantly less in the Enbrel group than in the methotrexate group at week 52. Significantly less radiographic progression (TSS) was observed with Enbrel in combination with methotrexate compared with Enbrel alone or methotrexate alone at week 52. The results for radiographic results (TSS), joint erosion and joint space narrowing (JSN) at week 52 are shown in Figure 2. There was a significant decrease in TSS compared with baseline in the combination of Enbrel with methotrexate group.
The percentage of patients without progression (TSS change ≤ 0.5) was higher in the Enbrel in combination with methotrexate and Enbrel groups compared with methotrexate at week 24 (74%, 68% and 56%, respectively; p < 0.05) and week 52 (80%, 68% and 57%, respectively; p < 0.05).
Safety, efficacy and immunogenicity were assessed in an open label study of Enbrel manufactured by the serum free process (SFP) in patients with rheumatoid arthritis. Based on indirect comparisons with historical data, the results were comparable to two previous phase 3 controlled studies in subjects with RA using Enbrel manufactured by a serum based process.
Juvenile idiopathic arthritis. The safety and efficacy of Enbrel were assessed in a two part study of 69 children with polyarticular course juvenile idiopathic arthritis (JIA) who had a variety of JIA onset types (polyarthritis, pauciarthritis, systemic onset). Patients aged 4 to 17 years with moderately to severely active polyarticular course JIA refractory to or intolerant of methotrexate were enrolled; patients remained on a stable dose of a single nonsteroidal anti-inflammatory drug and/or prednisone (≤ 0.2 mg/kg/day or 10 mg maximum). In part 1, all patients received 0.4 mg/kg (maximum 25 mg per dose) Enbrel SC twice weekly. In part 2, patients with a clinical response at day 90 were randomised to remain on Enbrel or receive placebo for four months and assessed for disease flare. Responses were measured using the ACR Pedi 30, defined as ≥ 30% improvement in at least three of six JIA core set criteria (active joint count, limitation of motion, physician and patient/ parent global assessments, functional assessment and ESR) with no more than one variable worsening by more than 30%. Disease flare was defined as a ≥ 30% worsening in three of six JIA core set criteria and a minimum of two active joints. They could also have ≥ 30% improvement in not more than one of six JIA core set criteria.
In part 1 of the study, 51 of 69 (74%) patients demonstrated a clinical response and entered part 2. In part 2, 6 of 25 (24%) patients remaining on Enbrel experienced a disease flare compared to 20 of 26 (77%) patients receiving placebo (p = 0.007). From the start of part 2, the median time to flare was ≥ 116 days for patients who received Enbrel and 28 days for patients who received placebo. Each component of the JIA core set criteria worsened in the arm that received placebo and remained stable or improved in the arm that continued on Enbrel. The data suggested the possibility of a higher flare rate among those patients with a higher baseline ESR. Of patients who demonstrated a clinical response at 90 days and entered part 2 of the study, some of the patients remaining on Enbrel continued to improve from month 3 through month 7, while those who received placebo did not improve.
In an open label, safety extension study, 58 paediatric patients from the above study (from the age of 4 years at time of enrolment) continued to receive Enbrel for up to 10 years. Rates of serious adverse events and serious infections did not increase with long-term exposure.
In another open label single arm study (n = 127), 60 patients with extended oligoarthritis (EO) (15 patients aged 2 to 4, 23 patients aged 5 to 11 and 22 patients aged 12 to 17 years old), 38 patients with enthesitis related arthritis (12 to 17 years old), and 29 patients with psoriatic arthritis (12 to 17 years old) were treated with Enbrel at a dose of 0.8 mg/kg (up to a maximum of 50 mg per dose) administered weekly for 12 weeks. In each of the JIA subtypes, the majority of patients met ACR Pedi 30 criteria and demonstrated clinical improvement in secondary endpoints such as number of tender joints and physician global assessment. The safety profile was consistent with that observed in other JIA studies.
Of the 127 patients in the parent study, 109 participated in the open label extension study and were followed for an additional 8 years for a total of up to 10 years. At the end of the extension study, 84/109 (77%) patients had completed the study; 27 (25%) while actively taking Enbrel, 7 (6%) had withdrawn from treatment due to low/inactive disease; 5 (5%) had restarted Enbrel following an earlier withdrawal from treatment; and 45 (41%) had stopped Enbrel (but remained under observation); 25/109 (23%) patients permanently discontinued from the study. Improvements in clinical status achieved in the parent study were generally maintained for all efficacy endpoints during the entire follow-up period. Patients actively taking Enbrel could enter an optional withdrawal re treatment period once during the extension study based on investigator's judgement of clinical response. 30 patients entered the withdrawal period. Due to the small number of data points, these results should be interpreted with caution.
One malignancy, Hodgkin's disease was reported in the first year of the extension study in an 18 year old EO JIA patient. The number (exposure-adjusted rate per 100 patient years) of serious adverse events, malignancies, and serious infections was 40 (5.85 EP100PY), 1 (0.15 EP100PY), and 14 (2.05 EP100PY), respectively. The safety profile was consistent with that observed in other JIA studies.
Long-term safety of Enbrel monotherapy (n = 103), Enbrel plus methotrexate (n = 294), or methotrexate monotherapy (n = 197) were assessed for up to 3 years in a registry of 594 children aged 2 to 18 years with juvenile idiopathic arthritis, 39 of whom were 2 to 3 years of age. Overall, infections were more commonly reported in patients treated with Enbrel compared to methotrexate alone (3.8 versus 2%), and the infections associated with Enbrel use were of a more severe nature.
Studies have not been done in patients with juvenile idiopathic arthritis to assess the effects of continued Enbrel therapy in patients who do not respond within 3 months of initiating Enbrel therapy. Additionally, studies have not been conducted to assess the effects of reducing the recommended dose of Enbrel following its long-term use in patients with JIA.
The long-term effects of Enbrel on the growth and development of children are not known. No formal clinical trials have been conducted in children aged 2 to 3 years. However, limited safety data from a patient registry suggest that the safety profile in children aged 2 to 3 years of age is similar to that seen in adults and children aged 4 years and older, when dosed every week with 0.8 mg/kg subcutaneously.
Adults with psoriatic arthritis. The efficacy of Enbrel was assessed in a randomised, double blind, placebo-controlled study of 205 patients with psoriatic arthritis. Patients were between 18 and 70 years of age and had active psoriatic arthritis (≥ 3 swollen joints and ≥ 3 tender joints) in at least one of the following forms: (1) distal interphalangeal (DIP) involvement; (2) polyarticular arthritis (absence of rheumatoid nodules and presence of psoriasis); (3) arthritis mutilans; (4) asymmetric psoriatic arthritis; or (5) spondylitis-like ankylosis. Patients also had plaque psoriasis with a qualifying target lesion ≥ 2 cm in diameter. Patients currently on methotrexate therapy (stable for ≥ 2 months) could continue at a stable dose of ≤ 25 mg/week methotrexate. Doses of 25 mg Enbrel or placebo were administered SC twice a week for 6 months. At the end of the double-blind study, patients could enter a long-term open label extension study for a total duration of up to 2 years.
The clinical responses were expressed as percentages of patients achieving the ACR 20, 50 and 70 response and percentages with improvement in Psoriatic Arthritis Response Criteria (PsARC). The PsARC endpoint comprises of four measures: (1) patient global assessment, (2) physician global assessment, (3) joint pain/ tenderness score and (4) joint swelling score. Achievement of the PsARC endpoint requires improvement in at least two of the four measures, one of which must be joint pain/ tenderness or swelling and no worsening in any of the four measures. Data have not been evaluated to establish whether Enbrel inhibits progressive joint destruction in psoriatic arthritis. Results are summarised in Table 7.
In this study, the psoriatic skin lesions of patients with active arthritis were also improved with Enbrel treatment compared with placebo. In a subset of patients with psoriasis involvement ≥ 3% of body surface area, improvements in the Psoriasis Area and Severity Index (PASI) were assessed at month 3 and month 6. The PASI is a composite score calculated from disease activity scores and the fraction of body surface area involvement. PASI results are presented in Table 8.
Among patients with psoriatic arthritis who received Enbrel, the clinical responses were apparent at the time of the first visit (4 weeks) and were maintained through 6 months of therapy. Enbrel was significantly better than placebo in all measures of disease activity (p < 0.001) and responses were similar with and without concomitant methotrexate therapy.
In this study, structural joint damage was assessed radiographically and expressed as change in modified Total Sharp Score (TSS) and its components, the erosion score and joint space narrowing score (JSN). The possible range for the modified TSS was 0 to 370. Radiographs of hands and wrists were obtained at baseline and months 6, 12 and 24.
The 1 year analyses as shown in Table 9, indicates that the difference between treatment groups was significant for mean annualized rate of change from baseline in TSS, erosion scores and for JSN. In addition, significantly more subjects in the Enbrel group had no progression (≤ 0 change) in TSS from baseline, compared with subjects in the placebo group.
The modified TSS at 6, 12 and 24 months are presented in Table 10 for those patients who entered year 2 and provided radiographs during the second year of the study.
In subjects who received placebo during the controlled part of the study and Enbrel in the open label part, further radiographic progression was inhibited after subjects began receiving Enbrel. Enbrel treatment resulted in improvement in physical function during the double blind period and this benefit was maintained during the longer-term exposure of up to 2 years.
Quality of life in psoriatic arthritis patients was assessed using the Health Assessment Questionnaire (HAQ) and SF-36 instruments. There was a statistically significant improvement in mean HAQ score from 1.1 to 0.5 on a scale of 0 to 3 for patients treated with Enbrel. The SF-36 showed improvements in the physical but not the mental components of the quality of life score.
Adults with ankylosing spondylitis. The efficacy of Enbrel was assessed in 2 randomised, double blind, placebo-controlled studies in 361 patients with ankylosing spondylitis. The largest of these trials (n = 277) enrolled patients who were between 18 and 70 years of age and had active ankylosing spondylitis as defined by the modified New York Criteria for Ankylosing Spondylitis. Patients were to have evidence of active disease based on visual analog scale (VAS) scores of ≥ 30 for average of duration and intensity of morning stiffness plus VAS scores of ≥ 30 for at least 2 of the following 3 parameters: patient global assessment; average of VAS values for nocturnal back pain and total back pain; average of 10 questions on the Bath Ankylosing Spondylitis Functional Index (BASFI). The duration of this study was up to 24 weeks and patients had a mean diagnosis of AS for 10 years. Patients with complete ankylosis of the spine were excluded from study participation. Patients taking hydroxychloroquine, sulfasalazine, methotrexate or prednisolone (≤ 10 mg/day) or equivalent could continue these drugs at stable doses for the duration of the study. Doses of 25 mg of Enbrel (based on dose finding studies in patients with rheumatoid arthritis) or placebo were administered subcutaneously twice a week for 6 months.
The primary measure of efficacy was a 20% improvement in the Assessment in Ankylosing Spondylitis (ASAS 20) response criteria. Compared to placebo, treatment with Enbrel resulted in significant improvements in clinical response as early as 2 weeks after the initiation of therapy (see Figure 3).
At 12 weeks, the ASAS 20/50/70 responses were achieved by 60%, 45% and 29%, respectively, of patients receiving Enbrel, compared to 27%, 13% and 7%, respectively, of patients receiving placebo (p < 0.001 for Enbrel vs placebo). Similar results were seen at week 24. (See Table 11.)
Adults with nonradiographic axial spondyloarthritis.

Study 1.

The efficacy of Enbrel in patients with nonradiographic axial spondyloarthritis (nr-AxSpA) was assessed in a randomised, 12 week double blind, placebo-controlled study followed by an open label period for up to an additional 92 weeks. The study evaluated 215 adult patients (modified intent to treat population) with active (baseline BASDAI score of ≥ 4) nr-AxSpA (18 to 49 years of age), defined as those patients meeting the ASAS classification criteria of axial spondyloarthritis but not the modified New York criteria for AS. Patients were also required to have an inadequate response or intolerance to two or more NSAIDs. In the double blind period, patients received Enbrel 50 mg weekly or placebo for 12 weeks and in the open label period, all patients received Enbrel 50 mg weekly for up to an additional 92 weeks. Throughout the study, patients were required to continue on an optimal tolerated dose of NSAIDs. The primary measure of efficacy was a 40% improvement in at least three of the four ASAS domains and absence of deterioration (ASAS 40) in the remaining domain at week 12 of the double blind period. MRIs of the sacroiliac joint and spine and CRP were obtained to assess inflammation at baseline and at week 12. Results from the double blind period are included below, unless noted otherwise.
Compared to placebo, treatment with Enbrel resulted in statistically significant improvement in the ASAS 40, ASAS 20 and ASAS 5/6. Significant improvement was also observed for the ASAS partial remission and BASDAI 50. Week 12 results are shown in the following table (see Table 12).
At week 12, there was an improvement in the secondary MRI endpoint SPARCC (Spondyloarthritis Research Consortium of Canada) score for the sacroiliac joint for patients receiving Enbrel. Adjusted mean change from baseline was -3.8 for Enbrel treated (n = 95) versus -0.8 for placebo treated (n = 105) patients.
The secondary endpoints physical function and health related quality of life were assessed using the BASFI (Bath Ankylosing Spondylitis Functional Index), EuroQol 5D and the SF-36 questionnaires. Enbrel showed greater improvement in the BASFI, EQ5D Overall Health State Score and the SF-36 Physical Component Score (PCS) from baseline to week 12 compared to placebo. Other measures of quality of life and anxiety/ depression scales (including Ankylosing Spondylitis Quality of Life (ASQoL) Scores, Ankylosing Spondylitis Work Instability Index (AS-WIS) and Hospital Anxiety and Depression Scale (HADS)), and the Bath Ankylosing Spondylitis Patient Global Assessment Score (BAS-G), all secondary endpoints, showed no evidence of difference between the etanercept and placebo groups.
Clinical responses among nr-AxSpA patients who received Enbrel (as assessed by ASAS 40) were apparent at the time of the first visit (2 weeks) and were maintained through 2 years of therapy. Improvements in health related quality of life (as assessed by SF-36) and physical function (as assessed by BASFI) were also maintained through 2 years of therapy. See Figure 4.
The proportions of subjects in the mITT who achieved ASAS 40 were measured at a number of time points in the open label period. At week 12, 101 subjects who had been randomised to etanercept contributed to the ASAS 40 outcome. By week 104, 81 subjects who had been randomised to etanercept contributed to the ASAS 40 outcome. Last observation carried forward was used to handle missing values. Based on exploratory analyses, there were no decreases in the proportions of subjects who achieved ASAS 40 at the measurement time points over the open label period compared to week 12. There are no data on the effects of etanercept on disease progression or structural damage in nr-AxSpA patients. The 2 year data did not reveal any new safety findings.

Study 2.

This multi-centre, open label, phase 4, 3-period study evaluated the withdrawal and retreatment of Enbrel in patients with active nr-AxSpa who achieved an adequate response (inactive disease defined as Ankylosing Spondylitis Disease Activity Score (ASDAS) C-reactive protein (CRP) less than 1.3) following 24 weeks of treatment.
209 adult patients with active nr-AxSpa (18 to 49 years of age), defined as those patients meeting the Assessment of SpondyloArthritis International Society (ASAS) classification criteria of axial spondyloarthritis (but not meeting the modified New York criteria for AS), having positive MRI findings (active inflammation on MRI highly suggestive of sacroiliitis associated with SpA) and/or positive hsCRP (defined as high sensitivity C-reactive protein [hsCRP] > 3 mg/L), and active symptoms defined by an ASDAS CRP greater than or equal to 2.1 at the screening visit received open label Enbrel 50 mg weekly plus stable background NSAID at the optimal tolerated anti inflammatory dosage for 24 weeks in Period 1. Patients were also required to have an inadequate response or intolerance to two or more NSAIDs. At week 24, 119 (57%) patients achieved inactive disease and entered into the Period 2 40-week withdrawal phase where subjects discontinued etanercept, yet maintained the background NSAID. The primary measure of efficacy was the occurrence of flare (defined as an ASDAS erythrocyte sedimentation rate (ESR) greater than or equal to 2.1) within 40 weeks following withdrawal of Enbrel. Patients who flared were retreated with Enbrel 50 mg weekly for 12 weeks (Period 3).
In Period 2, the proportion of patients experiencing ≥ 1 flare increased from 22% (25/112) at week 4 to 67% (77/115) at week 40. Overall, 75% (86/115) patients experienced a flare at any time point within 40 weeks following withdrawal of Enbrel.
The key secondary objective of Study 2 was to estimate time to flare after withdrawal of Enbrel. The median time to flare following withdrawal of Enbrel was 16 weeks (95% CI: 13-24 weeks). Less than 25% of patients in Study 1 who did not have treatment withdrawn experienced a flare over the equivalent 40 weeks as in Period 2 Study 2. The time to flare was shorter in subjects who discontinued Enbrel treatment (Study 2) compared to subjects who received continuous etanercept treatment (Study 1).
Of the 87 patients who entered Period 3 and were retreated with Enbrel 50 mg weekly for 12 weeks, 62% (54/87) reachieved inactive disease, with 50% of them reachieving it within 5 weeks (95% CI: 4-8 weeks).
Adults with plaque psoriasis. The safety and efficacy of Enbrel were assessed in two randomised, double blind, placebo-controlled studies. Study 1 evaluated 652 patients with chronic plaque psoriasis who were ≥ 18 years old, had active but clinically stable plaque psoriasis involving ≥ 10% of the body surface area and had a minimum psoriasis area and severity index (PASI) of 10 at screening. Enbrel was administered subcutaneously at doses of 25 mg once a week, 25 mg twice a week or 50 mg twice a week for 6 consecutive months. During the first 12 weeks of the double blind treatment period, patients received placebo or one of the above three Enbrel doses. After 12 weeks of treatment, patients in the placebo group began treatment with blinded Enbrel (25 mg twice weekly); patients in the active treatment groups continued to week 24 on the dose to which they were originally randomised. This study also had a drug withdrawal period during which patients who achieved PASI improvement of at least 50% at week 24 had treatment stopped. Patients were observed off treatment for the occurrence of rebound (PASI ≥ 150% of baseline) and for the time to relapse (defined as a loss of at least half of the improvement achieved between baseline and week 24). Upon relapse, patients were retreated with Enbrel in a blinded fashion at the dose they had been receiving at week 24.
Study 2 evaluated 583 patients and had the same inclusion criteria as study 1. Patients in this study received a dose of 25 mg or 50 mg Enbrel, or placebo subcutaneously twice a week for 12 weeks and then all patients received open label 25 mg Enbrel twice weekly for an additional 24 weeks.
The primary efficacy endpoint in both studies was the proportion of patients in each treatment group that achieved the PASI 75 (i.e. at least a 75% improvement in the PASI score from baseline) at 12 weeks. The results of the primary and secondary endpoints of both studies are shown in Table 13.
Among patients with plaque psoriasis who received Enbrel, significant responses relative to placebo were apparent at the time of the first visit (2 weeks) for the mean percent improvement in PASI, Dermatologist Static Global Assessment of Psoriasis, Dermatology Life Quality Index and Patient Global Assessment of Psoriasis and were maintained through 24 weeks of therapy.
During the withdrawal period in study 1, symptoms of psoriasis gradually returned with a median time to disease relapse of 3 months. No rebound flare of disease and no psoriasis related adverse events were observed. Retreatment with Enbrel resulted in a similar magnitude of response as was seen during the initial double blind portion of the study.
At weeks 4, 8 and 12 of study 2, the 50 mg twice weekly group had a significantly higher PASI 75 response rate than the 25 mg twice weekly group (p < 0.05, see Figure 5). The majority of patients who were initially randomised to 50 mg twice weekly and had their Enbrel dose decreased at week 12 to 25 mg twice weekly maintained their PASI 75 response through week 36. For patients who received 25 mg twice weekly throughout the study, the PASI 75 response continued to improve between weeks 12 and 36.
Subjects enrolled in either study 1 or study 2 (parent studies) were eligible to enter a phase III, open label study to evaluate the long-term safety, tolerability, and maintenance of efficacy of Enbrel in adults with plaque PsO. During the extension study, patients in one arm received Enbrel 50 mg once weekly for 48 additional weeks (n = 321). (See Figure 6.)
Enbrel 50 mg once weekly continued to provide durable efficacy as demonstrated by the percentage of subjects maintaining PASI 50, 75 and 90 responses over time. It was also well tolerated in this population and its safety profile was maintained throughout the extension study.
Paediatric patients with plaque psoriasis. The efficacy of Enbrel was assessed in a randomised, double blind, placebo-controlled study in 211 paediatric patients aged 4 to 17 years with moderate to severe plaque psoriasis (as defined by a sPGA score ≥ 3, involving ≥ 10% of the BSA, and PASI ≥ 12). Eligible patients had a history of receiving phototherapy or systemic therapy, or were inadequately controlled on topical therapy.
Patients received Enbrel 0.8 mg/kg (up to 50 mg) or placebo once weekly for 12 weeks. At week 12, more patients randomised to Enbrel had positive efficacy responses (e.g. PASI 75) than those randomised to placebo. See Table 14.
After the 12 week double blind treatment period, all patients received Enbrel 0.8 mg/kg (up to 50 mg) once weekly for an additional 24 weeks. Responses observed during the open label period were similar to those observed in the double blind period.
During a randomised withdrawal period, significantly more patients rerandomised to placebo experienced disease relapse (loss of PASI 75 response) compared with patients rerandomised to Enbrel. With continued therapy, responses were maintained up to 48 weeks.
At week 12, the percent improvement in PASI scores from baseline was significantly higher in Enbrel treated patients compared to placebo treated patients, across all baseline disease severity subgroups (see Table 15).
This study was conducted in children with moderate or severe psoriasis. Due to the risks associated with Enbrel in children (see Section 4.4 Special Warnings and Precautions for Use), only patients with severe disease should be treated.
Immunocompetence. Evaluations of immunocompetence were performed on 49 Enbrel treated patients with active RA. No evidence of immunosuppression was found in evaluations of delayed type hypersensitivity skin testing, enumeration of immune effector cell populations and immunoglobulins and in vitro testing of neutrophil and T cell function.
Antibodies. Antibodies to Enbrel, all non-neutralising, were detected in 4 out of 96 RA patients who received Enbrel at a dose of 25 mg twice a week for up to 3 months in a placebo-controlled trial. Results from JIA patients were similar to those seen in adult RA patients treated with Enbrel. No apparent correlation of antibody development to clinical response or adverse events was seen. Of 98 patients with psoriatic arthritis who have been tested, no patient has developed antibodies to Enbrel. Among 175 ankylosing spondylitis patients treated with Enbrel, 3 patients were reported with antibodies to Enbrel, none were neutralising. In double blind studies up to 6 months duration in plaque psoriasis, about 1% of the 1,084 patients developed antibodies to Enbrel, none were neutralising.

5.2 Pharmacokinetic Properties

Absorption.

Etanercept is slowly absorbed from the site of subcutaneous (SC) injection, reaching maximum concentration between 24 and 96 hours after a single dose. The absolute bioavailability is 76% as calculated in a population pharmacokinetic analysis of several studies. With twice weekly doses, it is anticipated that steady-state concentrations may be two to five-fold greater than those observed after single doses. After a single SC dose of 25 mg Enbrel, the average maximum serum concentration observed in healthy volunteers was 1.65 ± 0.66 mg/L, and area under the curve was 235 ± 96.6 mg.hr/L. Dose proportionality has not been formally evaluated, but there is no apparent saturation of clearance across the dosing range.

Distribution.

A bi-exponential curve is required to describe the concentration time curve of etanercept. The central volume of distribution of etanercept is 7.6 L, while the volume of distribution at steady state is 10.4 L.
After continued dosing of RA patients (n = 25) with Enbrel for 6 months with 25 mg twice weekly, the median observed level was 3.0 mg/L (range 1.7 to 5.6 mg/L).

Metabolism.

No formal pharmacokinetic studies have been conducted to examine the metabolism of etanercept or the effects of renal or hepatic impairment.

Excretion.

Etanercept is cleared slowly from the body. The half-life is approximately 80 hours. Clearance is approximately 0.066 L/hr in patients with RA, somewhat lower than the value of 0.11 L/hr observed in healthy volunteers. Additionally, the pharmacokinetics of etanercept in rheumatoid arthritis patients, plaque psoriasis and ankylosing spondylitis patients are similar.
Serum concentration profiles at steady state were comparable among patients with RA treated with 50 mg Enbrel powder for injection once weekly and those treated with 25 mg Enbrel powder for injection twice weekly. A single 50 mg/mL injection of Enbrel was also found to be bioequivalent to two simultaneous injections of 25 mg/mL. The mean (± standard deviation) Cmax, Cmin and partial AUC were 2.4 ± 1.5 mg/L, 1.2 ± 0.7 mg/L and 297 ± 166 mg.h/L, respectively, for patients treated with 50 mg Enbrel once weekly (n = 21); and 2.6 ± 1.2 mg/L, 1.4 ± 0.7 mg/L and 316 ± 135 mg.h/L for patients treated with 25 mg Enbrel twice weekly (n = 16). Serum concentrations in patients with RA have not been measured for periods of dosing that exceed 6 months. In an open label, single dose, two treatment crossover study in healthy volunteers, etanercept administered as a single injection of Enbrel 50 mg solution for injection was found to be bioequivalent to two simultaneous injections of Enbrel 25 mg powder for injection. The mean (± standard deviation) Cmax and AUC(0-t) are expressed in Table 16.
Although there is elimination of radioactivity in urine after administration of radiolabelled etanercept to patients and volunteers, increased etanercept concentrations were not observed in patients with acute renal or hepatic failure. The presence of renal and hepatic impairment should not require a change in dosage. There is no apparent pharmacokinetic difference between men and women.
Methotrexate has no effect on the pharmacokinetics of etanercept. The effect of Enbrel on the human pharmacokinetics of methotrexate has not been investigated.
The data described above were derived from studies using Enbrel manufactured using a serum based process.

Special populations.

Elderly (> 65 years).

The impact of advanced age was studied in the population pharmacokinetic analysis of Enbrel serum concentrations. Clearance and volume estimates in patients aged 65 to 87 years were similar to estimates in patients less than 65 years of age.

Patients with juvenile idiopathic arthritis.

In a polyarticular juvenile idiopathic arthritis (JIA) trial with Enbrel, 69 patients (age 4 to 17 years) were administered 0.4 mg Enbrel/kg twice weekly for three months. Serum concentration profiles were similar to those seen in adult rheumatoid arthritis patients. The youngest children (4 years of age) had reduced clearance (increased clearance when normalised by weight) compared with older children (12 years of age) and adults. Simulation of dosing suggests that while older children (10-17 years of age) will have serum levels close to those seen in adults, younger children will have appreciably lower levels.

Paediatric patients with plaque psoriasis.

Patients with paediatric plaque psoriasis (aged 4 to 17 years) were administered 0.8 mg/kg (up to a maximum dose of 50 mg per week) of Enbrel once weekly for up to 48 weeks. The mean serum steady-state trough concentrations ranged from 1.6 to 2.1 mg/L at weeks 12, 24, and 48. These mean concentrations in patients with paediatric plaque psoriasis were similar to the concentrations observed in patients with juvenile idiopathic arthritis (treated with 0.4 mg/kg Enbrel twice weekly, up to maximum dose of 50 mg per week). These mean concentrations were similar to those seen in adult patients with plaque psoriasis treated with 25 mg Enbrel twice weekly.

5.3 Preclinical Safety Data

Genotoxicity.

Genotoxicity studies showed no evidence of gene mutations or chromosomal damage.

Carcinogenicity.

Long-term animal studies have not been conducted to evaluate the carcinogenic potential of Enbrel (see Section 4.4 Special Warnings and Precautions for Use).

6 Pharmaceutical Particulars

6.1 List of Excipients

Enbrel powder for injection contains mannitol, sucrose and trometamol as excipients.
Enbrel solution for injection also contains sucrose, sodium chloride, arginine hydrochloride, monobasic sodium phosphate dihydrate, dibasic sodium phosphate dihydrate and water.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Powder for injection.

Store at 2°C to 8°C. Refrigerate. Do not freeze. The solution should be used immediately after reconstitution. If not used immediately, Enbrel solution must be refrigerated in the vial at 2°C to 8°C after reconstitution and used within 6 hours.
Prior to reconstitution, the powder may be stored at temperatures up to a maximum of 25°C for a single period of up to 4 weeks. Enbrel should be discarded if exposed to high temperatures, or if not used within 4 weeks of initial removal from refrigeration.

Solution for injection (pre-filled syringe, dose-dispenser cartridge and auto-injector).

Store at 2°C to 8°C. Refrigerate. Do not freeze. May be stored at temperatures up to a maximum of 25°C for a single period of up to 4 weeks. Enbrel should be discarded if exposed to high temperatures, or if not used within 4 weeks of initial removal from refrigeration.
Keep the pre-filled syringes, dose-dispenser cartridges and the auto-injectors in the outer carton in order to protect from light.
For additional advice on storing Enbrel, contact Pfizer Medical Information on 1800 675 229.

6.5 Nature and Contents of Container

Powder for injection.

Enbrel powder for injection cartons contain 4 clear glass vials (2 mL, Type 1 glass) with Teflon coated rubber stoppers, aluminium seals and flip-off plastic caps. Enbrel is also supplied with 4 pre-filled syringes containing 1 mL water for injections and 8 alcohol swabs. The pre-filled syringes are also made of Type 1 glass. The rubber closure of the diluent syringe contains latex (see Section 4.4 Special Warnings and Precautions for Use). Four vial adaptors and four 27 gauge needles are provided in the carton.

Pre-filled syringe (solution for injection).

Enbrel solution for injection is supplied in a kit containing four single-dose pre-filled glass syringes containing Enbrel solution. The needle cover contains natural rubber (latex) (see Section 4.4 Special Warnings and Precautions for Use). Four alcohol swabs are also are provided in the carton.

Auto-injector (solution for injection).

The auto-injector consists of a syringe made from clear Type 1 glass with a 27 gauge needle, rubber needle cover, and plastic plunger. The needle cap of the pre-filled auto-injector contains dry natural rubber (a derivative of latex) (see Section 4.4 Special Warnings and Precautions for Use). Cartons contain 1 or 4 Enbrel auto-injectors with 2 or 4 alcohol swabs, respectively.

Dose-dispenser cartridge (solution for injection).

Dose-dispenser cartridge holds a plastic cassette which contains a clear type 1 glass pre-filled syringe with a stainless steel 27-gauge needle, natural rubber needle cover supplemented by a polypropylene rigid needle shield, and bromobutyl rubber compliant plunger stopper. The pre-filled syringe contains 25 mg or 50 mg of etanercept. The needle cover of the pre-filled syringe in dose-dispenser cartridge contains dry natural rubber (latex) (see Section 4.4 Special Warnings and Precautions for Use).
Cartons contain 1 or 4 single-use dose-dispenser cartridges of Enbrel (25 mg or 50 mg) and 2 or 8 alcohol swabs.

6.6 Special Precautions for Disposal

Enbrel is for single use only. In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Chemical structure.

Etanercept is a human tumour necrosis factor receptor p75 Fc fusion protein produced by recombinant DNA technology in a Chinese hamster ovary (CHO) mammalian expression system. Etanercept is a dimer of a protein genetically engineered by fusing the extracellular ligand-binding domain of human tumour necrosis factor receptor-2 (TNFR2/p75) to the Fc domain of human IgG1. This Fc component contains the hinge, CH2 and CH3 regions but not the CH1 region of IgG1. Etanercept contains 934 amino acids and has an apparent molecular weight of approximately 150 kilodaltons. Etanercept is now manufactured using a serum-free process..

CAS number.

185243-69-0.

7 Medicine Schedule (Poisons Standard)

S4, Prescription only medicine.

Summary Table of Changes