Kindler’s Centrexion posts knee pain data as phase 3 nears

Osteoarthritis of the left knee. (Courtesy of James Heilman, M.D. [CC BY-SA 3.0])(By James Heilman, MD (Own work) [CC BY-SA 3.0 ( or GFDL (], via Wikimedia Commons)

Jeffrey Kindler’s Centrexion Therapeutics has posted six-month data from a phase 2b trial of its nonopioid treatment for knee pain. Differences in pain levels experienced by patients who took the experimental synthetic form of trans-capsaicin and placebo narrowed over the second half of the trial but remained big enough for Centrexion to claim a victory.

When Centrexion reported three-month data on the treatment for moderate to severe knee osteoarthritis pain late last year, it found a -1.5 or -1.6 difference in pain levels between the treatment and placebo arms of the study depending on the scale used.

After six months, the difference on the two scales had fallen to -1.3 and -0.9. The difference of -1.3 amounted to a statistically significant p value of 0.0002. Centrexion also claimed statistical significance for the -0.9 difference, although at 0.067 its p value came in above the established cutoff point of 0.05. The biotech claimed statistical significance because it had prespecified a p value of 0.1 as statistically significant.

The importance of such distinctions is now disappearing into Centrexion’s rearview though as it barrels toward the start of a phase 3 trial. Centrexion is aiming to get the trial underway later this year. And CMO Randall Stevens, M.D., thinks the data generated to date are cause for confidence.

“Not only are we seeing an onset of pain reduction in days, treatment with CNTX-4975 resulted in much larger pain reductions than has been seen with other pain therapeutics in knee osteoarthritis and we are seeing this response endure for six months,” Stevens said in the statement. “Importantly, in the context of treating a chronic condition, we are seeing these exciting efficacy responses with a safety profile that looks like placebo.”

That safety profile is central to Centrexion’s pitch for CNTX-4975. If the drug can safely treat pain by inactivating the fibers that send signals to the brain, it could establish itself as the go-to option for patients suffering from chronic conditions.