After 2 share-crushing flops, Ampio claims phase 3 success

Osteoarthritis of the knee (Courtesy of Bruce Blaus [CC BY-SA 4.0])

Ampio Pharmaceuticals has claimed success in a phase 3 osteoarthritis trial at the third attempt.

Investigators enrolled 169 patients with pain due to severe osteoarthritis of the knee and assigned them to receive Ampion or placebo at a six-to-one ratio. The primary endpoint assessed how patients performed against osteoarthritis responder criteria. But, rather than limit the control cohort to patients in this study, Ampio pooled the results from the 206 subjects with severe osteoarthritis who received saline across its late-phase program.

The 144 patients who received Ampion in the latest trial outperformed this pooled cohort in terms of the responder criteria, resulting in Ampio reporting that the study met its primary endpoint with a p value of 0.001.

That was enough for Ampio to start looking forward to filing for approval.

“We look forward to working closely with the U.S. Food and Drug Administration as we prepare to submit our biologics license application for Ampion,” Ampio CEO Michael Macaluso said in a statement.

Investors were initially less effusive. While the two previous phase 3 failures each wiped 60% off the firm’s stock price, the readout from the latest trial triggered a single-digit bump in premarket trading. But things picked up later, driving the stock up 40%.

The previous trials assessed performance against the WOMAC osteoarthritis index. Ampio switched to OMERACT-OARSI responder criteria for the latest study. Had the earlier trials used the OMERACT-OARSI responder criteria, Ampio thinks they would have cleared the efficacy bar.