BioCardia rejigs phase 3 heart failure data to find a path forward for cell therapy

BioCardia’s data safety monitoring board already warned that the phase 3 CardiAMP cell therapy heart failure trial was not going to make the primary endpoint. And so the California biotech is showcasing some other endpoints instead, hoping to persuade investors that the autologous cell therapy has a future.

CardiAMP was tested in 110 patients with advanced chronic heart failure, with mean follow-up at 20 months. The cell therapy 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 primary endpoint was a three-pronged evaluation of the condition: all-cause death, nonfatal major adverse cardiac and cerebrovascular events (MACCE) and a six-minute walk distance test from baseline to 12 months. BioCardia revealed an interim look at the study at the Technology and Heart Failure Therapeutics 2024 annual meeting.

After 20 months, patients who received a dose of CardiAMP had a 37% relative risk reduction in all-cause heart death equivalents and a 9% relative risk reduction in nonfatal incidences of heart attacks, strokes and hospitalization due to heart failure. Patients also had a 5% lower rate of heart death equivalents at up to two years compared to control patients who received just heart failure medication.

BioCardia also said that CardiAMP was associated with “trends” toward reduced ventricular tachyarrhythmias, enhanced heart function as measured by left ventricular ejection fraction and improved NTproBNP, which is a marker of heart distress.

In a subgroup analysis that focused on patients with high NTproBNP at baseline, there was an 86.2% relative risk reduction in heart death equivalents and a 23.9% relative risk reduction in MACCE. This group also had a 17% lower rate of heart death equivalents at the two-year mark compared to the control group.

“While the trial’s data safety monitoring board determined that the study would not meet its composite primary endpoint that included six-minute walk distance per the trial design, the positive results for reduced heart death equivalents, reduced MACCE, and safety indicate potential for this therapy to improve outcomes for patients with advanced chronic heart failure,” said the trial’s co-principal investigator, Amish Raval, M.D., director of clinical cardiovascular research and professor of medicine at the University of Wisconsin-Madison.

BioCardia did not report updated results for the six-minute walk test nor any safety data.

The FDA has approved a follow-up phase 3 clinical trial to test CardiAMP in patients with elevated NTproBNP, which the biotech hopes will validate the interim results.

“We are encouraged by the totality of today’s results and anticipate that both the final 24-month data analysis and follow-on trial outcomes would be consistent with this highly positive data,” BioCardia CEO Peter Altman, Ph.D., said in a Monday statement.

In September 2023, BioCardia announced that the data safety monitoring board had determined the study would not meet its primary endpoint. 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. 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.

That disclosure sent BioCardia’s shares down to 62 cents. The stock has only once breached the $1 mark since then. As trading opened Monday, the shares plunged another 14% to 49 cents.