Shares of Histogenics (HSGX), a clinical-stage company focused on the development of restorative cell therapies, fell nearly 64% in pre-market trading Wednesday after the company said its phase 3 trial of NeoCart failed to meet the primary endpoint of a statistically significant improvement in pain and function in a dual threshold responder analysis one year after treatment as compared to microfracture.

The company said 74.2% of the NeoCart patients in the modified Intent to Treat (mITT) population showed clinically meaningful improvements in pain and function compared to 62.0% of microfracture patients at one year. However, in this mITT population, patients who received NeoCart treatment attained a statistically significant improvement in pain and function six months after treatment as compared to those treated with microfracture.

Both NeoCart and microfracture were well tolerated and exhibited strong safety profiles, Histogenics said.

“We continue to analyze the data and are in the process of scheduling a meeting with the FDA to discuss the results and prepare for a potential submission of a biologics license application for NeoCart. We wish to acknowledge and thank the patients and investigators who participated in the trial and shared their positive experiences with NeoCart,” said Histogenics CEO Adam Gridley.