(CLDN) Announces Option Agreement With Servier

Servier Receives Exclusive Option to Enter Into Worldwide, Ex-U.S., Research Collaboration and License for Celladon’s Novel Small Molecule SERCA2b Modulators for the Treatment of Diabetes and Metabolic Diseases

SAN DIEGO, Feb. 24, 2014  — Celladon Corporation (Nasdaq:CLDN), a clinical-stage biotechnology company focused on developing novel therapies by applying its leadership position in the field of SERCA enzymes, today announced that Celladon and Servier have entered into an option agreement for a potential worldwide ex-U.S. research collaboration and license agreement for the discovery and development of novel SERCA2b modulators for the treatment of type 2 diabetes and other metabolic diseases. The collaboration would leverage Celladon’s novel compounds, proprietary assays, and screening technology for isolation of small molecule modulators of SERCA enzymes.

Under the terms of the agreement, Celladon granted Servier an exclusive option to license the worldwide, ex-U.S., rights to the small molecule program in the field of diabetes and other metabolic disorders for a certain period. Servier’s decision to exercise its option will be based upon the outcome of a series of pre-defined in vitro and in vivo studies to be performed by the parties. In the event Servier exercises its option, Celladon would receive certain upfront, research support and milestone payments, as well as royalties on sales. Celladon and Servier would jointly support the discovery effort, while Servier would be primarily responsible for all costs associated in and for its territory with a global development plan, as well as ex-U.S. regulatory approval and commercialization of any compound selected as a lead candidate. Celladon would retain all U.S. rights to any compounds and lead candidates developed through this collaboration and license agreement.

About Celladon’s Small Molecule Program targeting SERCA2b enzymes

The focus of our small molecule research program relates to the SERCA2b isoform of SERCA enzymes. Specifically, these enzymes control calcium movement in the endoplasmic reticulum (ER) in all human cells. SERCA2b enzyme levels become deficient when cells are stressed, and accumulate unfolded proteins in the ER, known as ER stress. There has been a proliferation of publications in scientific medical literature supporting the important role of ER stress in many diseases and conditions, including heart failure, diabetes and neurodegenerative diseases. We believe we are the industry leader in isolating small molecule modulators of the SERCA2b enzyme, which can correct underlying calcium dysregulation and ER stress. Our proprietary, novel, first-in-class, compounds have demonstrated activity in multiple preclinical models of diseases and conditions.

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, which is a clinical syndrome characterized by poor heart function, resulting in inadequate blood flow to meet the body’s metabolic needs, as well as 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 addition, we have identified a number of potential first-in-class compounds addressing novel targets in diabetes and neurodegenerative diseases with our small molecule platform of SERCA2b modulators.

About Servier

Founded in 1954, Servier is the first independent French pharmaceutical research company. Its development is based on relentless pursuit of innovation in the following therapeutic areas: cardiovascular diseases, metabolic diseases, neurologic diseases, psychiatric diseases, rheumatic diseases, and oncology.

In 2013, the company reported revenue of €4.2 billion. 92% of Servier medicines are prescribed internationally. At least 25% of revenue from Servier drugs is reinvested in R&D every year. Servier has a strong international presence in 140 countries and employs more than 21,000 people worldwide. The Servier Group contributed 35% to the 2013 French trade surplus in the pharmaceutical sector.

More information is available at: www.servier.com

Forward-Looking Statements

Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements regarding Servier’s exercise of its option to enter into a research collaboration and license agreement with Celladon, as well as Celladon’s small molecule program generally. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These forward-looking statements are based upon Celladon’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation, risks associated with the process of conducting product development activities and clinical trials and obtaining regulatory approval to commercialize product candidates, as well as our reliance on third parties and the need to raise additional funding when needed in order to conduct our business. These and other risks and uncertainties are described more fully in Celladon’s filings with the Securities and Exchange Commission, including without limitation its Registration Statement on Form S-1 that was originally filed with the Securities and Exchange Commission on October 10, 2013, and the amendments thereto. All forward-looking statements contained in this press release speak only as of the date on which they were made. Celladon undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

CONTACT: Fredrik Wiklund
         Vice President, Corporate Development and Investor Relations
         (858) 432-7215
         fwiklund@celladon.net

         Servier Communication Department
         Phone: +33 (0)1 55 72 60 37
         Email: presse@servier.fr

Servier Receives Exclusive Option to Enter Into Worldwide, Ex-U.S., Research Collaboration and License for Celladon’s Novel Small Molecule SERCA2b Modulators for the Treatment of Diabetes and Metabolic Diseases

SAN DIEGO, Feb. 24, 2014 (GLOBE NEWSWIRE) — Celladon Corporation (Nasdaq:CLDN), a clinical-stage biotechnology company focused on developing novel therapies by applying its leadership position in the field of SERCA enzymes, today announced that Celladon and Servier have entered into an option agreement for a potential worldwide ex-U.S. research collaboration and license agreement for the discovery and development of novel SERCA2b modulators for the treatment of type 2 diabetes and other metabolic diseases. The collaboration would leverage Celladon’s novel compounds, proprietary assays, and screening technology for isolation of small molecule modulators of SERCA enzymes.

Under the terms of the agreement, Celladon granted Servier an exclusive option to license the worldwide, ex-U.S., rights to the small molecule program in the field of diabetes and other metabolic disorders for a certain period. Servier’s decision to exercise its option will be based upon the outcome of a series of pre-defined in vitro and in vivo studies to be performed by the parties. In the event Servier exercises its option, Celladon would receive certain upfront, research support and milestone payments, as well as royalties on sales. Celladon and Servier would jointly support the discovery effort, while Servier would be primarily responsible for all costs associated in and for its territory with a global development plan, as well as ex-U.S. regulatory approval and commercialization of any compound selected as a lead candidate. Celladon would retain all U.S. rights to any compounds and lead candidates developed through this collaboration and license agreement.

About Celladon’s Small Molecule Program targeting SERCA2b enzymes

The focus of our small molecule research program relates to the SERCA2b isoform of SERCA enzymes. Specifically, these enzymes control calcium movement in the endoplasmic reticulum (ER) in all human cells. SERCA2b enzyme levels become deficient when cells are stressed, and accumulate unfolded proteins in the ER, known as ER stress. There has been a proliferation of publications in scientific medical literature supporting the important role of ER stress in many diseases and conditions, including heart failure, diabetes and neurodegenerative diseases. We believe we are the industry leader in isolating small molecule modulators of the SERCA2b enzyme, which can correct underlying calcium dysregulation and ER stress. Our proprietary, novel, first-in-class, compounds have demonstrated activity in multiple preclinical models of diseases and conditions.

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, which is a clinical syndrome characterized by poor heart function, resulting in inadequate blood flow to meet the body’s metabolic needs, as well as 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 addition, we have identified a number of potential first-in-class compounds addressing novel targets in diabetes and neurodegenerative diseases with our small molecule platform of SERCA2b modulators.

About Servier

Founded in 1954, Servier is the first independent French pharmaceutical research company. Its development is based on relentless pursuit of innovation in the following therapeutic areas: cardiovascular diseases, metabolic diseases, neurologic diseases, psychiatric diseases, rheumatic diseases, and oncology.

In 2013, the company reported revenue of €4.2 billion. 92% of Servier medicines are prescribed internationally. At least 25% of revenue from Servier drugs is reinvested in R&D every year. Servier has a strong international presence in 140 countries and employs more than 21,000 people worldwide. The Servier Group contributed 35% to the 2013 French trade surplus in the pharmaceutical sector.

More information is available at: www.servier.com

Forward-Looking Statements

Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements regarding Servier’s exercise of its option to enter into a research collaboration and license agreement with Celladon, as well as Celladon’s small molecule program generally. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These forward-looking statements are based upon Celladon’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation, risks associated with the process of conducting product development activities and clinical trials and obtaining regulatory approval to commercialize product candidates, as well as our reliance on third parties and the need to raise additional funding when needed in order to conduct our business. These and other risks and uncertainties are described more fully in Celladon’s filings with the Securities and Exchange Commission, including without limitation its Registration Statement on Form S-1 that was originally filed with the Securities and Exchange Commission on October 10, 2013, and the amendments thereto. All forward-looking statements contained in this press release speak only as of the date on which they were made. Celladon undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

CONTACT: Fredrik Wiklund
         Vice President, Corporate Development and Investor Relations
         (858) 432-7215
         fwiklund@celladon.net

         Servier Communication Department
         Phone: +33 (0)1 55 72 60 37
         Email: presse@servier.fr