News & Events

--Continued reduction in cardiovascular events and no safety concerns observed through three years of follow up in the MYDICAR high dose group—

--Oral Presentation by Dr. Barry H. Greenberg at 9 AM CET on November 19, 2013 --

San Diego, California, November 18, 2013/PRNewswire/ --

Celladon Corporation, a clinical stage biotechnology company focused on developing novel therapies by applying its leadership position in the field of SERCA enzymes, today announced that on behalf of the CUPID 1 Trial investigators, Dr. Barry H. Greenberg will present the full three year long-term follow up results from Phase 2a of the CUPID 1 trial in an oral presentation at the American Heart Association Scientific Sessions 2013 Conference held in Dallas, Texas. Phase 2a of the CUPID 1 trial investigated Celladon’s product candidate MYDICAR in three dose groups for the treatment of advanced heart failure.

The details of the presentation are as follows:

�?� Session Type: Abstract Oral Session

�?� Session Title: 502. Novel Cell, Tissue Engineering, and Gene Based Strategies For Heart

Failure

�?� Abstract Title: Long Term Follow-up Of Patients With Advanced Heart Failure

Following A Single Intracoronary Infusion Of AAV1/SERCA2a

�?� Presentation Date/Time: 11/19/2013 9:00:00 AM Central time

�?� Presenter: Barry H. Greenberg M.D., FACC, Director, Advanced Heart Failure Treatment

Program; Professor of Medicine, University of California, San Diego

Dr. Greenberg stated, “The results of the long-term follow up of the CUPID patients at 36 months are a major step forward in the development of a promising new therapy for treating heart failure. Evidence of continued reduction in events with high dose MYDICAR compared to placebo extending out to 36 months and the persistence of transgene expression in the heart are very encouraging findings that support the possibility that MYDICAR has an important impact on the clinical course of heart failure patients.”

“The durability of treatment effect and lack of safety concerns observed through 36 months in the MYDICAR high dose group are very encouraging,” said Krisztina Zsebo, Ph.D., President and Chief Executive Officer of Celladon Corporation. “The continued clinical deterioration seen in the placebo patients receiving ongoing optimal standard therapy emphasizes the tremendous unmet medical need in people with advanced heart failure.’

In the additional two year follow up period of the CUPID 1 trial, the durability of reduced cardiovascular and terminal events previously observed in the MYDICAR high dose cohort at 12 months was maintained. The following recurrent cardiovascular and terminal events were tracked over the three years in all MYDICAR dose groups: myocardial infarction, worsening heart failure, heart failure-related hospitalization, left ventricular assist device (LVAD) placement, heart transplantation, and all-cause death. The risk of pre-specified recurrent

cardiovascular events through full three years of follow up was reduced by 82% in the high dose group compared to the placebo group (p=0.048, where p-value is the statistical probability of a result due to chance alone).

In addition, the survival probability over time was higher for patients in all MYDICAR dose groups compared to the placebo group, especially in the high dose group. At three years post administration, there were 13 deaths: six in the placebo group, three in the low-dose group, three in the mid-dose group and one in the high-dose group. Finally, persistence of the vector DNA as assessed by qPCR testing was demonstrated in three high dose MYDICAR patients in whom a biopsy was feasible, but not from patients in the placebo or lower dose groups. No safety concerns were noted during the three year follow-up period.

About the CUPID 1 Trial

Phase 2a of the CUPID 1 trial was a clinical trial using Celladon’s lead product candidate

MYDICAR in patients with advanced heart failure. In this 39-patient trial, MYDICAR was found to be safe and well-tolerated, reduced heart failure-related hospitalizations, improved patients’ symptoms and quality of life, and improved key markers of cardiac function predictive of survival, such as elevated levels of natriuretic peptides and end systolic volume. Three dose levels of MYDICAR were administered, and the high-dose MYDICAR group met the primary endpoint versus placebo at six months, and all positive trends were confirmed at 12 months. The hazard ratio at 12 months for the high-dose MYDICAR group versus placebo for recurrent adjudicated clinical events was 0.12 (p=0.003) representing a risk reduction of 88% with MYDICAR versus placebo. No safety concerns were noted.

About Celladon

We are a clinical-stage biotechnology company applying our leadership position in the field of calcium dysregulation by targeting SERCA enzymes to develop novel therapies for diseases with tremendous unmet medical needs. Sarco/endoplasmic reticulum Ca2+-ATPase, or SERCA, enzymes are a family of enzymes that play an integral part in the regulation of intra-cellular calcium in all human cells. Calcium dysregulation is implicated in a number of important and complex medical conditions and diseases, such as heart failure, diabetes and neurodegenerative diseases. Our therapeutic portfolio for diseases characterized by SERCA enzyme deficiency includes both gene therapies and small molecule compounds. MYDICAR, our most advanced

product candidate, uses gene therapy to target SERCA2a, which is an enzyme that becomes deficient in patients with heart failure. In a 39-patient randomized, double-blind, placebo controlled Phase 2a trial in patients with systolic heart failure, which we refer to as CUPID 1,

MYDICAR was found to be safe and well-tolerated, reduced heart failure-related hospitalizations, improved patients’ symptoms, quality of life and serum biomarkers, and improved key markers of cardiac function predictive of survival, such as end systolic volume.

We expect to complete enrollment of CUPID 2 in the first half of 2014 and announce results from this trial in mid-2015.

For further information, please contact:

Fredrik Wiklund

Vice President, Corporate Development and Investor Relations

+1- 858-432-7215

[email protected]