Pfizer Inc. and Eli Lilly and Company announced top-line results from a Phase 3 study evaluating tanezumab 2.5 mg and 5 mg. The objective of the study was to compare the long-term joint safety and 16-week efficacy of tanezumab relative to nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with moderate-to-severe osteoarthritis (OA) of the hip or knee. The tanezumab 5 mg treatment arm met two of the three co-primary efficacy endpoints, demonstrating a statistically significant improvement in pain and physical function compared to NSAIDs at the 16-week analysis, while patients’ overall assessment of their OA was not statistically different than NSAIDs. Patients who received tanezumab 2.5 mg did not experience a statistically significant improvement in pain, physical function or patients’ overall assessment of their OA at 16 weeks compared to NSAIDs. In the safety analysis, there was a higher rate of joint safety events in the tanezumab arms compared to NSAIDs at 80 weeks; the difference was statistically significant. Joint safety was a composite measure consisting of adjudicated outcomes of rapidly progressive osteoarthritis (RPOA) type 1 or type 2, subchondral insufficiency fracture, osteonecrosis or pathological fracture. Tanezumab is a monoclonal antibody that is part of an investigational class of non-opioid chronic pain medications known as nerve growth factor (NGF) inhibitors.
“We are analyzing these findings in the context of the recent Phase 3 results as we assess potential next steps for tanezumab,” said Ken Verburg, tanezumab development team leader, Pfizer Global Product Development. “We plan to review the totality of data from our clinical development program for tanezumab with regulatory authorities.”
“Lilly and Pfizer recognize the significant unmet needs for patients living with osteoarthritis,” said Christi Shaw, president, Lilly Bio-Medicines. “We are committed to understanding these results for people who suffer from chronic pain.”
In this study, tanezumab 2.5 mg or 5 mg was administered subcutaneously (SC) every eight weeks, for a total of 56 weeks. Preliminary safety data showed that the overall adverse event profile with tanezumab was generally consistent with previous studies of tanezumab in OA, though in this study, discontinuations due to adverse events were higher among those receiving tanezumab compared to NSAIDs during the 56-week treatment period. The study also included a 24-week safety follow-up period, for a total of 80 weeks of observation. There were 10 deaths in the study; nine occurred in the tanezumab treatment arms and one in the NSAID treatment arm. None were considered treatment-related: five occurred during the treatment period and five occurred after the treatment period.
The incidence of the primary composite joint safety endpoint was 7.1 percent in the tanezumab 5 mg arm, 3.8 percent in the tanezumab 2.5 mg arm and 1.5 percent in the NSAIDs arm. RPOA accounted for the majority of events observed in the composite joint safety endpoint. The incidence of RPOA overall was 6.3 percent in the tanezumab 5 mg arm, 3.2 percent in the tanezumab 2.5 mg arm and 1.2 percent in the NSAIDs arm. The majority of RPOA events (81 percent) observed with tanezumab were RPOA type 1. There was one patient with osteonecrosis in the tanezumab 5 mg arm, and no patients in the tanezumab 2.5 mg or NSAIDs arms. Subchondral insufficiency fracture was observed in seven, six and four patients receiving tanezumab 5 mg, tanezumab 2.5 mg and NSAIDs, respectively. There were no pathological fractures observed in patients treated with tanezumab or NSAIDs. The incidence of total joint replacement was 8.0 percent in the tanezumab 5 mg arm, 5.3 percent in the tanezumab 2.5 mg arm and 2.6 percent in the NSAIDs arm.
The full results from this study will be submitted for future scientific publication or presentation.