Celladon tanks as gene therapy Mydicar fails in mid-stage trial

Shares of USA-based clinical-stage biotechnology company Celladon Corp (Nasdaq: CLDN) plunged 74% to $3.50 shortly after markets opened on Monday in New York, after the company revealed that its Phase IIb CUPID2 trial did not meet its primary and secondary endpoints.

CUPID2 is a randomized, double-blind, placebo-controlled, multinational trial evaluating a single, one-time, intracoronary infusion of the cardiovascular gene therapy agent Mydicar (AAV1/SERCA2a) versus placebo added to a maximal, optimized heart failure drug and device regimen.

In the study, the primary endpoint comparison of Mydicar to placebo resulted in a hazard ratio of 0.93 (0.53, 1.65 95%CI) (p=0.81), defined as heart failure-related hospitalizations or ambulatory treatment for worsening heart failure. The secondary endpoint comparison of Mydicar to placebo, defined as all-cause death, need for a mechanical circulatory support device, or heart transplant, likewise failed to show a significant treatment effect. The efficacy endpoint analyses were performed on the (n=243) modified intent to treat population (mITT), which excludes clinical events that occurred in patients who did not receive Mydicar or placebo, or which occurred prior to dosing. All other exploratory efficacy endpoints (improvement in New York Heart Association classification, 6 Minute Walk Test, and Quality of Life) were also inconsistent with a treatment effect. No safety issues were noted.