CAMBRIDGE, Mass., Oct. 04, 2016 (GLOBE NEWSWIRE) — Dimension Therapeutics, Inc. (NASDAQ:DMTX), a biopharmaceutical company advancing novel, adeno-associated virus (AAV) gene therapies targeting the liver, a key organ for human metabolism, today announced that the U.S. Food and Drug Administration (FDA) granted orphan drug designation for the Company’s product candidate, DTX401, the first AAV gene therapy to enter IND-enabling studies for the treatment of GSDIa. Designed to address the underlying genetic defect, DTX401 delivers stable expression and activity of the enzyme glucose-6-phosphatase (G6Pase). DTX401 has been shown to improve G6Pase activity and reduce hepatic glycogen levels, a well-described biomarker of disease progression, in multiple in vivo preclinical models.

“We are pleased to receive U.S. orphan designation for our second inherited metabolic disease candidate, DTX401, recognizing the substantial need for a new approach to treating individuals with GSDIa,” said Dr. Annalisa Jenkins, MBBS, FRCP, Chief Executive Officer of Dimension. “Affected individuals are unable to tolerate a fast and are at high risk for hypoglycemia, or low blood sugar, coma and potentially death. Today, there are limited options, requiring patients to adhere to burdensome dietary regimens in order to maintain blood glucose at an appropriate level. DTX401 continues to advance in part through a cooperative research and development agreement, or CRADA, with Janice Chou, Ph.D., and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and we look forward to developing a treatment alternative that we believe holds great potential for addressing unmet needs for patients.”

The FDA Office of Orphan Products Development grants orphan designation to drugs and biologics intended for treatment of rare diseases or conditions that affect fewer than 200,000 people in the United States. Orphan drug designation provides certain benefits to sponsors planning to test a product for use in a rare disease or condition. These benefits include tax credits for qualified clinical trials costs, and exemption from FDA user fees, and upon approval, the product may qualify for seven years of market exclusivity.

Background on GSDIa
GSDIa, the most common genetically inherited glycogen storage disease, has significant unmet needs. Patients have a defective gene for the enzyme glucose-6-phosphatase, resulting in the inability to regulate blood sugar (glucose). Hypoglycemia in GSDIa patients can be life-threatening, while the accumulation of the complex sugar glycogen in certain organs and tissues can impair the ability of these tissues to function normally. If chronically untreated, patients develop severe lactic acidosis, can progress to renal failure, and die in infancy or childhood. There are no approved pharmacological therapies, and no ongoing clinical development beyond dietary approaches. An estimated 6,000 or more patients are affected by GSDIa worldwide.

About Dimension Therapeutics
Dimension Therapeutics, Inc. (NASDAQ:DMTX) is the leader in discovering and developing new therapeutic products for people living with devastating rare diseases associated with the liver, based on the most advanced, mammalian adeno-associated virus (AAV) gene delivery technology. Dimension is actively progressing its broad pipeline, which features programs addressing unmet needs for patients suffering from inherited metabolic diseases, including OTC deficiency, GSDIa, citrullinemia type 1, PKU, Wilson disease, a collaboration with Bayer in hemophilia A, and a wholly owned clinical program in hemophilia B. The company targets diseases with readily identifiable patient populations, highly predictive preclinical models, and well-described, and often clinically validated, biomarkers. Founded in 2013, Dimension maintains headquarters in Cambridge, Massachusetts.

For more information, please visit http://www.dimensiontx.com.

Cautionary Note Regarding Forward-Looking Statements
This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding the progress of Dimension’s portfolio and lead programs, including DTX401, the timing, scope or likelihood of regulatory filings and approvals, the progress and results of preclinical studies, and our ability to develop and advance product candidates into, and successfully complete, clinical studies. All such forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include the risks that Dimension’s product candidates, including DTX401, will not successfully be developed or commercialized in the times indicated or at all; and the risks described under the caption “Risk Factors” in Dimension Therapeutics’ Quarterly Report on Form 10-Q for the quarter ended June 30, 2016, which is on file with the Securities and Exchange Commission, as well as other risks detailed in Dimension Therapeutics’ additional filings with the Securities and Exchange Commission. All information in this press release is as of the date of the release, and Dimension Therapeutics undertakes no duty to update this information unless required by law.

CONTACT: CONTACT:

Jean Franchi
Chief Financial Officer
Dimension Therapeutics
617-714-0709
[email protected]

Burns McClellan, on behalf of Dimension Therapeutics
Media: Justin Jackson
212-213-0006, ext.327
[email protected]