European Medicines Agency Restricts Use of Prostate Cancer Medicine Xofigo

LONDON:
The European Medicines Agency (EMA) has concluded its review of the cancer medicine Xofigo (radium-223 dichloride), and has recommended restricting its use to patients who have had two previous treatments for metastatic prostate cancer (prostate cancer that has spread to the bone) or who cannot receive other treatments.
Xofigo must also not be used with the medicines Zytiga (abiraterone acetate) and the corticosteroid prednisone or prednisolone. Xofigo should not be used with other systemic cancer therapies, except for treatments to maintain reduced levels of male hormones (hormone therapy). The medicine should also not be used in patients who have no symptoms, in line with the current indication; in addition, the use of Xofigo is not recommended in patients with a low number of bone metastases called osteoblastic bone metastases.
The review of Xofigo was carried out by EMA’s Pharmacovigilance Risk Assessment Committee (PRAC) after data from a clinical study suggested that patients given Xofigo in combination with Zytiga and prednisone/prednisolone could be at risk of dying earlier and had more fractures than patients given placebo (a dummy treatment) with Zytiga and prednisone/prednisolone. The study included patients with no or only mild symptoms, whereas Xofigo is only authorised in patients with symptoms. In addition, the combination used in this study is now contraindicated. In the study, patients given the combination with Xofigo died on average 2.6 months earlier than those given the combination with placebo. In addition, 29 per cent of patients who received the Xofigo combination had fractures, compared with 11 per cent of patients given the placebo combination.
It is thought that Xofigo, which is taken up by the bone, accumulates at sites where the bone is already damaged, for example by osteoporosis or micro-fractures, increasing the risk of fracture. However, the reasons for a possible earlier death seen in this study are not fully understood. The company that markets Xofigo will have to conduct studies to further characterise these events and clarify the mechanisms behind them.
The PRAC’s recommendations have now been endorsed by EMA’s Committee for Medicinal Products for Human Use (CHMP) and will be sent to the European Commission for a final legal decision.