Dimension Therapeutics Goes Public on Nasdaq to Advance Gene Therapies for Hemophilia and Rare Liver Diseases

Dimension Therapeutics, a gene therapy company based in Cambridge, Massachusetts, specializing in hemophilia treatments, filed for an initial public offering (IPO) this September. The company aims to leverage public capital to support its ongoing research into gene therapies for hemophilia and other rare diseases. This IPO filing comes just five months after Dimension raised $65 million from crossover investors, including both public market and private equity firms. In recent years, crossover investors have poured significant capital into biotech startups, a trend that has undoubtedly facilitated Dimension’s path to going public.

Dimension was co-founded by Fidelity Biotechnology Co., Ltd. and RegenxBio, a company specializing in gene therapy, in October 2013. Within less than two years, it completed its IPO application and secured $90 million in venture capital funding, including a collaboration with Bayer established last year. Dimension’s primary products are gene therapies targeting liver-related rare diseases and genetic mutation disorders. The flagship products launched by Dimension are listed in the table below. Except for DTX201, a treatment for hemophilia A developed in partnership with Bayer, whose commercial rights are jointly owned by both parties, all other products’ commercial rights are solely owned by Dimension.



To those unfamiliar with Dimension, the company is merely one among the many gene therapy startups that have emerged in recent years. With the rise of gene therapy, attention has been drawn to a highly controversial pioneer in the field, James Wilson, a gene therapy expert at the University of Pennsylvania. He co-led the notorious 1999 human gene therapy clinical trial that resulted in the tragic death of 18-year-old Jesse Gelsinger. In the aftermath, however, Wilson gradually became a key figure in the field of gene medicine. He successfully identified adeno-associated viruses (AAVs) as effective vectors for drug delivery, thereby pioneering AAV-based gene therapies such as RegenX, which involve inserting correct gene sequences into patients’ defective genes to combat disease. Many gene therapy companies, including Dimension, were founded based on this technology.


Dimension aims to leverage this technology to develop treatments for hemophilia A and B, as well as several rare metabolic disorders. The two target rare diseases currently announced by Dimension are ornithine transcarbamylase (OTC) deficiency—the condition that affected Jesse Gelsinger—and glycogen storage disease type Ia. Currently, Dimension’s most advanced and in-depth research focuses on hemophilia B. On September 10, the company announced that the U.S. Food and Drug Administration (FDA) had granted orphan drug designation to its DTX101 therapy, with clinical trials for DTX101 planned by the end of the year.

Currently, there are at least seven therapies for treating hemophilia (a disease in which patients experience impaired blood clotting due to missing molecular structures); this is just one of them. Six publicly traded companies, including Spark Therapeutics (NASDAQ: ONCE), BioMarin Pharmaceutical (BMRN), Baxalta (BXLT), Biogen (BIIB), UniQure (QURE), and Sangamo Biosciences (SGMO), are conducting related research.


Through its collaboration with Bayer, Dimension has already commenced research on DTX-201, a gene therapy for hemophilia A. In June 2014, Dimension Therapeutics undertook a series of initiatives to advance its gene therapy programs, entering into an agreement with Bayer valued at approximately $250 million.

Under this agreement, Bayer will fund all preclinical studies and subsequent early-stage clinical trials for Dimension’s therapy targeting hemophilia A. Upon successful completion of these stages, Bayer will take responsibility for the final Phase III clinical trials and secure global commercial rights to the therapy. Meanwhile, Dimension will retain ownership of its hemophilia B therapy. Dimension’s major shareholders include Beacon Biosciences Risk Fund (effectively controlled by Fidelity), OrbiMed, and New Leaf Ventures, each holding more than 5% of Dimension’s shares.

Since gene therapy was “reborn,” marked by the discovery of drug “delivery vehicles” and promising early clinical data, the field has also encountered some setbacks. Several companies, including Avalanche Biotechnologies and Celladon, have seen their stock prices plummet due to disappointing clinical trial results.

In fact, regardless of the outcome of their IPO applications at the time, the current status of Dimension and RegenX, two gene therapy companies, serves as an excellent “barometer” for gauging investor sentiment toward gene therapies. Specifically, on October 21, Dimension announced its public offering of 5.5 million shares of common stock at $13 per share, and successfully listed on the Nasdaq Global Select Market on October 22 under the ticker symbol “DMTX.”

Translation: Liu Jianqiu

Editor: Zhang Nan