BioCardia's cell therapy flunks phase 3 heart failure trial, driving stock down

BioCardia’s dive into its paused phase 3 heart failure trial has failed to identify reasons to be optimistic about the primary endpoint. Weeks after the monitoring board recommended pumping the brakes, the biotech has revealed the study is unlikely to meet its main objective, putting another dent in its share price. 

News that the phase 3 trial was in trouble emerged in late July, when BioCardia told investors that the independent data safety monitoring board had recommended pausing enrollment pending the analysis of patients that were then completing one-year follow-up. BioCardia has now seen results from the 102 randomized patients who have completed their one-year review—and the news is bad.

The primary endpoint is a composite measure with three elements. On the first element—all-cause death including cardiac death equivalents such as heart transplant or left ventricular assist device placement—BioCardia’s cell therapy CardiAMP was no better than the control. Specifically, the rate of all-cause death and cardiac death equivalents after one year was 5.6% in the CardiAMP cohort and 5.3% in the control group.

CardiAMP fared no better on the other two elements. The rate of nonfatal major adverse cardiac events was similar in the two cohorts, with 16.7% in the treatment group versus 15.8% in the control, and BioCardia saw no significant difference in the change in six-minute walk test distance.

CardiAMP involves delivering a patient’s bone marrow cells to the heart via a catheter-based procedure with the hope of stimulating the body’s natural healing response. The failure of the therapy to significantly improve outcomes on any aspect of the composite endpoint in the phase 3 trial led BioCardia to conclude that the study is unlikely to succeed. Study sites are completing the treatment of patients previously enrolled in the trial, and BioCardia will continue to follow the participants. 

The company's analysis of all available follow-up in the patients tracked up to 24 months contains glimpses of possible efficacy. The rate of all-cause death and cardiac death equivalents was lower in the CardiAMP cohort, 8.3%, than the control arm, 13.2%. BioCardia also linked CardiAMP to a numerical improvement, 16.7% versus 23.6%, in nonfatal major adverse cardiac events.

“We are actively engaged in identifying patients who responded the most to the therapy and are considering other learnings with respect to trial design to inform this program and our other two ongoing clinical programs,” Peter Altman, Ph.D., BioCardia’s president and CEO, said in a statement. “We anticipate working with the principal investigators and executive steering committee on these efforts.”

Investor expectations are low. The latest update sent BioCardia’s stock down around 20% to 62 cents in premarket trading, adding to losses that have seen the share price slide by more than 60% in six months.