FDA puts clinical hold on Regeneron and Teva's pain drug fasinumab trial

Shares of Israeli generics giant Teva Pharmaceutical Industries (NYSE: TEVA) plunged 5.3% to 16,060 shekels after a Phase IIb clinical trial of fasinumab, which is partnered with US biotech firm Regeneron Pharmaceuticals (Nasdaq: REGN), was placed on hold by the US Food and Drug Administration. Regeneron’s shares dipped 1.33% to $366.73.

Fasinumab is an investigational nerve growth factor (NGF) antibody being investigated in patients with chronic low back pain. The FDA has requested an amendment of the study protocol after observing a case of adjudicated arthropathy in a patient receiving high dose fasinumab who had advanced osteoarthritis at study entry.

The news comes just weeks after Teva gained rights to fasinumab from Regeneron. Under the terms of the agreement signed last month, Teva will pay Regeneron $250 million upfront and share equally in the global commercial value, as well as ongoing research and development costs of around $1 billion. Japan’s Mitsubishi Tanabe (TYO: 4508) has rights to fasinumab in certain Asian markets.

As a result of the FDA decision, Regeneron completed an unplanned interim review of results and has stopped dosing in the study. The unplanned analysis showed clear evidence of efficacy with improvement in pain scores in all fasinumab groups compared to placebo at the 8- and 12-week time points (nominal p less than 0.01). Preliminary safety results are generally consistent with what has been previously reported with the class. The Phase IIb chronic low back pain study enrolled around 70% of the targeted 800 patients in four dose groups: placebo, 6mg subcutaneously monthly, 9mg subcutaneously monthly and 9mg intravenously every two months. Regeneron has notified health authorities and study investigators about the decision. Patients will continue to be followed for up to 36 weeks.