A pain medication being developed by pharmaceutical giants Pfizer Inc. and Eli Lilly & Co. showed promise in a large clinical trial as a treatment for osteoarthritis, the companies said late Tuesday.
The trial’s safety results will likely be a particular focus of investor scrutiny. In clinical trials held years ago, individuals with osteoarthritis had their conditions worsen while taking this class of drugs. For Pfizer PFE, -0.61% and Eli Lilly’s LLY, -1.46% drug, tanezumab, that concern and a related clinical hold delayed development by several years.
Of nearly 700 patients enrolled in the phase 3 trial, about 1.3% taking tanezumab showed rapidly progressive osteoarthritis, which was not observed in patients treated with a placebo. Other joint problems also occurred in the two groups treated with tanezumab, and higher rates of individuals taking the drug had total joint replacement surgery, as compared with the placebo group.
Related: Pfizer, Eli Lilly non-opioid pain drug nears finish line
The companies are “cautiously optimistic” about the path forward, but more data are still needed, especially from a large safety study for which results are expected next year, said Ken Verburg, clinical program development lead at Pfizer.
On joint safety, “we were hoping to see a little bit better balance between tanezumab and placebo,” Verburg told MarketWatch, noting that rapidly progressive osteoarthritis was only seen in the tanezumab patient groups. Still, “the numbers are small and one or two events from one treatment group to another could have changed the picture substantially.”
The results suggest potential for a new alternative to addictive opioids, an option that is lacking even many years into America’s devastating opioid-addiction crisis.
Read: Opioids are ravaging the U.S., but they’re still the best pain drug we’ve got
Osteoarthritis, a chronic joint condition that often occurs in older individuals, affects more than 30 million U.S. adults, according to the Centers for Disease Control and Prevention. Tanezumab is also in phase 3 trials for two other kinds of common pain, chronic low back and cancer pain.
Patients in the recent trial had previously tried pain medications like opioids and ibuprofen and had not had good-enough results, according to a release put out by Pfizer and Eli Lilly.
Those taking tanezumab, meanwhile, reported statistically significant improvements on three different measures of their condition, including pain and physical function, as compared with the placebo.
The drug could be a “significant, multibillion-dollar market opportunity” if potential safety issues are addressed, J.P. Morgan analyst Chris Schott said late last month, referring to several ongoing phase 3 trials.
Related: As powerful new opioid nears FDA approval, critics ask if U.S. is stoking its drug crisis
Another Wall Street analyst, EvercoreISI’s Josh Schimmer, has noted the “large unmet need for non-opioid options for pain in [osteoarthritis].” It’s possible that the right dose of the drug, or the right monitoring, could avoid the drug class’s safety problems, he said.
Regeneron Pharmaceuticals Inc. REGN, -1.83% and Teva Pharmaceutical Industries Ltd. TEVA, +0.05% are also developing another one of this class of drugs, called fasinumab, which also targets a protein called nerve growth factor to reduce pain. The companies announced results from a phase 3 trial in August and said they plan to advance the program.
Pfizer shares have surged 18% over the last three months, and Eli Lilly shares have surged 23%, compared with a 3.3% decline in the S&P 500 SPX, -0.55%
