The only things I’m surprised about is how long it took to discover the damage from such medications.
A phase 3 trial has painted a mixed picture of the safety and efficacy of Eli Lilly and Pfizer’s painkiller tanezumab.
Neither dose of the nerve growth factor (NGF) inhibitor hit all the co-primary efficacy goals, and both fared worse than placebo on the safety assessments.
I was always convinced that taking an “anti-nerve-growth” medication long term would lead to all kinds of unexpected and undesired insidious effects. While preventing new nerves from growing could conceivably lead to fewer nerves signaling pain, these drugs are not localized and affect the whole body.
After a lot of research, I found these types of medications to cause global neurologic disruption with very little benefit:
- Phase 3 Chronic Pain Program For Tanezumab
- Current Status of Anti-Nerve Growth Factor for Pain
- Anti-Nerve Growth Factor for Pain: Jan 2018
- Anti-Nerve Growth Factor for Pain: Jun 2016
- Nerve Growth Factor: Neuroscience and Therapy – May 2015
Tanezumab has come through a series of late-phase tests over the past year, with at least one of the tested doses hitting the primary endpoints across three clinical trials in osteoarthritis and chronic lower back pain. However, the studies also failed to quash long-standing safety concerns, which laid waste to the once-hyped NGF inhibitor field around a decade ago.
Now, Lilly and Pfizer have reported a set of data that clarify the safety concerns and add to questions about efficacy, prompting Wolfe Research analyst Tim Anderson to sound the death knell for the drug.
“To us, the product is likely dead, if not from a regulatory standpoint (i.e., is it even approvable?) then from a commercial one (i.e., will it ever sell?),” Anderson wrote in a note to investors.
Good riddance. I think this family of drugs will prove to be more and more harmful the longer it’s taken.
Lilly and Pfizer captured the efficacy data, which looked at pain, physical function and patients’ views of their osteoarthritis, at 16 weeks but continued monitoring them long after that to gather safety results, most notably through an 80-week assessment of a primary composite joint safety endpoint.
The one case of osteonecrosis—a bone disease—seen in the trial occurred in the high-dose arm.
And 8% of patients in the high-dose cohort required total joint replacement, as compared to 2.6% in the control group. Nine of the 10 deaths in the trial occurred in the tanezumab arms, but Lilly and Pfizer think they were all unrelated to the study drug.
The safety issues illustrated by clinical data are in keeping with earlier studies of NGF inhibitors, a class of drugs that was derailed around a decade ago by reports of higher rates of joint replacement in patients receiving the experimental molecules.
Regeneron and Teva Pharmaceutical also have an NGF inhibitor, fasinumab, in late-phase development.