Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Hexalen (David Bull Laboratories)
50 mg capsules
Indication: ovarian cancer
Hexamethylmelamine has been used in clinical trials for many years. It is related to the alkylating agents and can be used in combination with other anticancer drugs to treat stage III and IV ovarian cancer. The precise mechanism of action is unknown.
Absorption is good, but there is extensive first pass metabolism which produces varying plasma concentrations. The half-life is from 4-11 hours and involves the formation of metabolites which are excreted in the urine.
On the basis of the available evidence, hexamethylmelamine has been approved for use in combination with cyclophosphamide, doxorubicin and, if the patient can tolerate it, cisplatin. Hexamethylmelamine is also approved as monotherapy in patients who relapse after first-line therapy, as a response of 18% has been reported.
The patient should have a neurological examination before hexamethylmelamine treatment begins as neurotoxicity is common. This can affect the central nervous system or present as a peripheral neuropathy. Other adverse events include myelo suppression, nausea and vomiting.