Editor, – We welcome being recognised for transparency in supplying Therapeutic Goods Administration (TGA) evaluation data to Australian Prescriber to assist in the preparation of the new drug comment about denosumab (Prolia) (Aust Prescr 2010;33:194).
We were, however, surprised to read a statement, based on a meta-analysis1 that 'denosumab was not associated with a significant reduction in fracture risk in postmenopausal women', despite your review having previously described a clinical trial which showed statistically significant reductions in the incidence of vertebral, non-vertebral and hip fracture. This trial recruited 7868 patients and fractures were an independently adjudicated endpoint.2
The meta-analysis included three studies (996 patients in total) including a dose-ranging phase 2 study and a study in women with bone loss related to hormone ablative therapy for breast cancer (not an approved indication). Fractures were not a pre-planned outcome in any study analysed and were collected only as adverse events, neither confirmed nor independently adjudicated. Following the peer-reviewed publication of the pivotal fracture trial,2 any reference to the meta-analysis is profoundly limited.
The omission of these limitations from the new drug comment could leave the reader with the impression that the meta-analysis included data from the trial2 and that the statistically significant fracture outcomes were negated by the other studies in the meta-analysis.
We feel it important to highlight this so as not to mislead prescribers into believing that the TGA have granted marketing authorisation for a product that is '... not associated with a significant reduction in fracture risk in postmenopausal women'.
Cae Tolman
Senior medical advisor
Amgen Australia Pty Ltd
Sydney
