Celladon Anticipates Layoffs After Its Gene Therapy Trial Fails

Xconomy San Diego — 

The swiftly turning fortune of San Diego-based Celladon (NASDAQ: CLDN) could bring a note of caution to the hot field of gene therapy.

One year ago, Celladon said the FDA had granted its “breakthrough therapy” designation for Mydicar, Celladon’s gene therapy treatment for patients with severe heart failure. The company sought the designation based on its long-term analysis of Cupid1, a mid-stage clinical trial of Mydicar that showed a dramatic 88-percent reduction in heart failure-related hospitalizations among 39 patients.

But Celladon shares plunged more than 80 percent today after the company said an expanded follow-up study with 250 heart patients failed to meet both its primary primary and secondary goals. Celladon lost $11.04 a share, and closed at $2.64 a share.

During a conference call this morning, Celladon CEO Krisztina Zsebo characterized the results as surprising and disappointing, and her chief financial officer Paul Cleveland said layoffs and “other cost-cutting measures” are expected.

At the end of 2014, Celladon had about $85 million in available cash, which Cleveland said should last for at least the next 12 months. The company has yet to release first-quarter financial results.

Zsebo said Celladon is “still deep in data analysis” of the expanded study, dubbed Cupid2, and so she declined to provide much detail about the results. She said it’s unclear whether the treatment that showed so much promise last year wasn’t working, or if sufficient levels of the biologic drug had not been delivered to the heart.

“We are evaluating our remaining development programs in order to determine the best path forward to maximize shareholder value,” Szebo said during the call.

In a statement issued Sunday evening, Celladon quoted Barry Greenberg, a UC San Diego professor of medicine who is chairman of the executive clinical steering committee for the trial, saying, “This trial was extremely well-executed and adequately tested the hypothesis… [and] there were no safety issues.”

Celladon’s gene therapy is intended to boost production of an enzyme, SERCA2a, which plays a key role in recycling calcium in the heart’s muscle cells. Celladon’s treatment uses a small, benign virus to deliver a fresh supply of SERCA2a enzymes into the muscle cells of the heart. The company says Mydicar is intended for an estimated 350,000 patients in the United States who have been diagnosed with advanced chronic heart failure.

Current treatment options for such patients are usually expensive and involve a heart transplant or the surgical implantation of a pump known as a left ventricle assist device.

Out of hundreds of gene therapy clinical trials being done in the United States, Celladon said last April that it was the first U.S. company to win the FDA’s “breakthrough therapy” designation for a gene therapy program. It could not immediately be determined if any other gene therapy programs have since obtained the agency’s breakthrough therapy designation.