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 authorized 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% of patients who received the Xofigo combination had fractures, compared with 11% 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 characterize these events and clarify the mechanisms behind them.
The PRAC’s recommendations were endorsed by EMA’s Committee for Medicinal Products for Human Use (CHMP). The European Commission issued a final legal decision valid throughout the EU on 28 September 2018.
European Medicines Agency. 2018 September 28 [Epub]