- An experimental pain medication developed by Pfizer and Eli Lilly may be less likely to gain approval following a Thursday meeting in which advisors to the Food and Drug Administration weren't convinced that its safety risks will be adequately managed.
- The medication, called tanezumab, has been shown to improve pain and physical function in patients with osteoarthritis. However, tanezumab and other drugs that work like it have been shadowed by safety concerns, namely with regard to joint damage. Pfizer and Lilly proposed a plan to monitor and mitigate these issues should their drug gain approval, but a committee of FDA advisers — most of who are experts in immunology, medicine, drug safety and risk management — almost unanimously voted down the plan.
- While the FDA isn't obligated to follow such recommendations, it typically does. Geoffrey Porges, an analyst at SVB Leerink, wrote in a note to clients that the panel vote suggests Pfizer and Lilly will need to drum up more long-term safety data and a "more practical" mitigation strategy to secure approval, a task which Porges and his team expect to take at least two years. SVB Leerink now forecasts a 35% chance of tanezumab coming to market, down from 65%.
Tanezumab has attracted much attention due to the growing demand for new, non-opioid pain relievers. The drug works by blocking what are known as nerve growth factors, a type of molecule that plays a role in pain. Studies of tanezumab as well as a similar drug developed by Regeneron and Teva have shown some positive effects in patients experiencing osteoarthritis pain.
The benefit to tanezumab, however, appears modest, and may not be any greater than non-steroidal anti-inflammatory drugs like naproxen.
Tanezumab has also run into major obstacles that slowed a development journey that's now spanned more than 15 years and over 40 clinical studies. In 2010, the FDA placed holds on three nerve growth factor drugs after testing found unusual cases of joint damage. The agency later cleared these studies to proceed, but questions around safety have persisted.
Pfizer ultimately partnered with Lilly to advance its drug, with the pair restarting trials in 2015. By the time they submitted tanezumab for approval last March, the drug had supporting data from 20 clinical trials evaluating its safety and efficacy in osteoarthritis patients specifically, including three pivotal studies involving more than 4,500 participants with moderate to severe disease.
Thursday's meeting of FDA advisers didn't vote on whether tanezumab's benefits outweigh its risks, but rather whether Pfizer and Lilly's proposed plan to monitor the drug once it's on market would ensure the benefits outweigh the risks. The 19 to 1 vote against the drug suggests to some that the road to approval could now be significantly longer.
"While the [advisory committee] did not vote for or against approval, this resounding vote and the FDA's comments and briefing document suggest that the members and reviewers see the benefit from the drug as modest and the risk as significant," Porges wrote. Consensus among analysts is that peak annual sales of tanezumab will be around $520 million in 2030, according to Porges.
The negative vote could also impact Regeneron and Teva's plans for their similar-acting drug fasinumab. The companies have completed Phase 3 testing and have been discussing a path forward with regulators. They expect to decide on their next steps by June.