Pfizer-Lily’s Anti-NGF approach for osteoarthritis pain, Tanezumab, falls on it’s face in Phase 3 clinical trials.


The results for Pfizer-Lily’s phase 3 clinical trials of their Anti-NGF osteoarthritis pain killer drug are in, and things are not looking good for this drug. However, this comes to no surprise to us at Regenerative Times.

The drug is an antibody which selectively binds to, and inhibits NGF ( Nerve growth factor ). NGF levels increase in the body as a result of injury or inflammation. NGF has multiple roles in the human body, including regulating the immune system and ensuring the survival of pancreatic beta cells ( which are responsible for synthesizing insulin )

Many approaches targeting NGF have failed in the past, and Tanezumab has actually had it’s clinical trials suspended by the FDA once before due to it worsening arthritis, but regardless, Pfizer-Lilly resumed developing the therapy and even received fast track designation by the FDA in 2017.

It’s understandable that some less than ideal approaches would be revisited in light of the recent focus on the opiod epidemic, but we find ourselves scratching our head why Pfizer-Lily continued developing this drug, knowing that there was a dose-dependent relation to rapidly worsening osteoarthritis symptoms in previous trials. The Phase 3 clinical data is just as grim:

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.

– Pfizer-Lily press release

One thing of note is that the lower 2.5mg dosage did not outperform common NSAIDs, but it did double the risk of rapidly progressing osteoarthritis ( versus NSAIDs ). A clinically effective dose, 5mg, more than tripled this risk! Again – they knew about this effect in earlier trials. We really hope some sanity prevails here and either Pfizer-Lily or the FDA hit the brakes on this approach.

Meanwhile, companies like Kolon Life Sciences, Merck, and many others are experimenting with growth factor / cell therapies that actually address the root cause of arthritic pain instead of focus on the symptoms. For example, Merck’s Sprifermin has shown cartilage regeneration and positive effects that last up to 3 years after an initial series of a few injections.

From the press release, Pfizer-Lily appears to be considering their options, but has not ruled out commercializing the drug. We hope that sanity prevails, and for the sake of osteoarthritis suffers, either Pfizer-Lily or the FDA decide to walk away from this approach.

You can read more at Pfizer-Lily’s press release here:


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