More positive results for Pfizer/Lilly’s non-opioid pain drug

Pfizer and Eli Lilly have announced more positive results from a phase 3 study of their non-opioid pain drug tanezumab, this time in chronic lower back pain (CBLP).

In the study, treatment with tanezumab 10mg met the primary endpoint, demonstrating a statistically significant improvement in pain at 16 weeks compared to placebo. The tanezumab 5mg arm demonstrated a numerical improvement in pain, but did not reach statistical significance compared to placebo at the week 16 analysis.

This is consistent with the drug’s results in osteoarthritis trials, where smaller doses were found to be less effective.

Tanezumab is also being investigated for cancer pain due to bone metastases.

Development of the nerve growth factor (NGF) inhibitor drug and rivals from the same class has been delayed by years because of the FDA’s concerns that they could accelerate joint destruction.

But the FDA allowed trials to restart in light of the opioid addiction crisis that has been linked with hundreds of thousands of deaths across America and has prompted action from the government – NGF inhibitors do not have the same addictive potential as opioid drugs such as fentanyl.

Preliminary safety data showed that tanezumab was generally well tolerated during the 56-week treatment period. Overall, rapidly progressive osteoarthritis (RPOA) was observed among 1.4 percent of patients receiving tanezumab and 0.1 percent of patients in the other treatment groups. The ratio of RPOA type 1 (accelerated joint space narrowing) to RPOA type 2 (damage or deterioration of the joint) observed with tanezumab in the study was 6:1.

Concerns are also growing about opioid addiction in the UK, where the use of opioid painkillers has dramatically increased over the past 20 years, rising by a third between 1998 and 2016. Earlier this week the Medicines and Healthcare products Regulatory Agency (MHRA) has convened an Expert Working Group to assess the risks and benefits of opioid medicines and see if current UK regulation is up to scratch.

An estimated 33 million Americans have CLBP, and approximately eight million of these patients suffer from moderate-to-severe CLBP. The condition is a leading cause of disability.