UPDATED: Celladon's heart drug grabs 'breakthrough' status at FDA

San Diego-based Celladon has nabbed a "breakthrough" drug designation from the FDA for its heart failure drug Mydicar. And its stock ($CLDN) jumped 12% on the news. The gene therapy uses a benign virus to insert the Serca2a gene into heart cells. The treatment is designed to spur an ailing heart to pump up blood flow in patients. The San Diego-based biotech, a 2012 Fierce 15 company, is currently conducting a Phase IIb study of the therapy with 250 patients. Results are expected next spring.

The BTD process could offer significant advantages for a small biotech like Celladon. In addition to attracting some positive attention in the industry, heart drugs in particular face a very high bar at the FDA. Getting an open door at the FDA could only work in Celladon's favor.

"We believe the BT designation will provide the opportunity to streamline our development program and more efficiently bring the product to market, including CMC, companion diagnostic, etc.," Celladon CEO Krisztina Zsebo tells FierceBiotech in an e-mail. "The question of how large a safety data base is required is going to be determined for the US by the CUPID 2 results. So far the FDA has asked for a total safety data base consistent with needing to conduct another Phase III trial roughly the size of CUPID 2, however they can reserve the right to reduce this requirement based on CUPID 2 results. Therefore, a Phase III trial may be required for MYDICAR in the US for approval. For EU, a safety data base of 205-230 MYDICAR treated patients may be acceptable for an MAA submission, so if CUPID 2 is successful, a second Phase III may not be required for EMA approval." Release