- Teva Pharmaceuticals and biotech partner Regeneron revealed Monday morning that a Phase 2b study of their chronic pain drug fasinumab has been placed on clinical hold by the U.S. Food and Drug Administration.
- The FDA also requested an amendment of the study protocol after a patient in the chronic low back pain study of fasinumab, which is being studied for the treatment of osteoarthritis pain and chronic low back pain, experienced a case of severe inflammation of the joints.
- As a result of the FDA request, Regeneron conducted an interim analysis of the study and decided to stop all dosing.
The clinical hold could mean a much more limited patient population for the drug, much smaller than the 30 million people that Regenron was touting previously – if it ever makes its past regulators. Currently, most patients are treated with opioids for pain. The companies are hoping to overtake the category.
This isn't the first setback for the class of drugs, which inhibit Nerve Growth Factor (NGF). In 2010, the FDA put the entire class on hold after it was uncovered that there was nerve damage in animal studies.
"Anti-NGF strategies appear to be efficacious in providing pain relief but we continue to be concerned about its overall safety profile," wrote Jefferies analyst Biren Amin in a note to investors. "Even if the clinical program for fasinumab is successful after making the adjustments announced today, we are concerned about the long-term effects as a chronic pain therapy. For these reasons, we continue to leave fasinumab out of our valuation."
The latest setback for the drug comes just a few weeks after Teva signed on for a share of the rights to fasinumab. Teva agreed to pay $250 million upfront in a deal that could be worth $1 billion.
Regeneron said that the interim analysis showed strong efficacy results from the drug over placebo and that the two companies are now designing a Phase 3 study that will exclude patients with osteoarthritis.
Other than the inflammatory joint problem with the osteoarthritis patient, who was on the highest dose of the drug, the companies said that fasinumab's safety profile was consistent with had been previously reported for the class.
Regeneron and Teva intend to submit plans for the late-stage trial to the FDA.
Pfizer and partner Eli Lilly & Co. are developing a competing drug in the class, tanezumab.