Celladon Corporation (Nasdaq:CLDN), a clinical-stage biotechnology company developing novel therapies for patients with heart failure and other diseases characterized by SERCA enzyme deficiencies, today announced that its lead product candidate, MYDICAR^®, has been granted breakthrough therapy designation by the U.S. Food and Drug Administration (FDA) for reducing hospitalizations for heart failure in NYHA class III or IV chronic heart failure patients who are NAb negative. This designation is intended to expedite the development and review of drugs for serious or life-threatening conditions and where preliminary clinical evidence suggests it provides a substantial improvement over existing therapies. Celladon is developing MYDICAR as a novel, first-in-class therapy for patients with chronic heart failure due to systolic dysfunction. MYDICAR uses genetic enzyme replacement therapy to correct the deficiency in the enzyme SERCA2a, which is an enzyme that becomes deficient in heart failure patients and results in inadequate pumping of the heart. Celladon has developed a companion diagnostic to identify the patients who are AAV1 NAb negative and therefore eligible for MYDICAR treatment.

"We are looking forward to working with the senior staff at the FDA to determine the most expeditious path to bring MYDICAR to patients with advanced heart failure. This breakthrough therapy designation validates MYDICAR's unique characteristics and clinical data to date and underscores the urgent need for new treatments for heart failure," said Krisztina Zsebo, Ph.D., president and CEO of Celladon. "MYDICAR has the potential to provide transformative disease-modifying effects with long-term benefits in heart failure patients with a single administration. Our goal is to bring MYDICAR to market as quickly as possible in the United States, where we estimate approximately 350,000 heart failure patients with currently limited remaining treatment options could be eligible for therapy."

Celladon is currently evaluating MYDICAR in the Phase 2b CUPID 2 trial to determine its efficacy in reducing the frequency of and/or delaying heart failure-related hospitalizations. This randomized, double-blind, placebo-controlled, multinational trial is evaluating a single intracoronary infusion of MYDICAR versus placebo added to a maximal, optimized heart failure regimen in  patients with NYHA class III or IV symptoms of chronic heart failure due to systolic dysfunction. Patient enrollment has been completed and 250 patients have been randomized in this trial. The Company expects to report results in April 2015.