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Roche Genentech Releases Letter to DMD Community Announcing Discontinuation of Clinical Trials Program for DMD

Today, Roche Genentech released a letter to the Duchenne muscular dystrophy (DMD) community regarding its decision to discontinue its DMD clinical development program. The full letter follows.

Letter to the DMD community from Roche Genentech:

Dear members of the Duchenne community,

We are writing to share with you unfortunate news about our clinical development program studying RG6206 (RO7239361), an investigational anti-myostatin adnectin protein, in ambulatory boys with DMD.

We are disappointed to announce that the clinical development program studying RG6206 (RO7239361) in Duchenne will be discontinued. This concerns both RG6206 studies: the open-label extension study of the phase 1b/2 THUNDERJET study, evaluating the safety and tolerability of RG6206 in ambulatory boys with DMD; and the phase 2/3 SPITFIRE study, evaluating the efficacy, safety, and tolerability of RG6206 in ambulatory boys with DMD. Our decision to close this program was made based on the results of a pre-planned interim data analysis of the phase 2/3 SPITFIRE study, which indicated that RG6206 was highly unlikely to demonstrate clinical benefit as defined by meeting the primary endpoint (change from baseline in the North Star Ambulatory Assessment [NSAA] total score versus placebo). As you know, NSAA is a 17-item rating scale that is used to measure functional motor abilities in ambulant children with DMD. It was used to assess the treatment effects with RG6206 in the phase 2/3 SPITFIRE study. No safety signals were observed in this analysis and the overall safety profile was similar to that seen in previous trials.

We have notified all the clinical trial sites and the investigators are now in the process of informing the study participants and families. Because SPITFIRE is a global trial with clinical sites in several countries, spanning many time zones, this may take some time and we acknowledge that members of the community might find out at different times and in different ways. It is our intention to provide as much information as we can to the community. To that end, we will be holding two global community WebEx meetings to accommodate different time zones on Friday, Nov. 8, at 7 a.m. GMT and 4 p.m. GMT/11 a.m. EST. The link to participate in either WebEx is:

We recognize this news is deeply disappointing for the Duchenne community, especially in view of the historical challenges in DMD drug development and the ongoing need for new treatment options to treat this devastating disease. While the science and large body of research gave us hope that RG6206 would have offered people living with DMD and their families a safe and effective treatment option, the results of the SPITFIRE study at this time led us to the difficult conclusion that this approach will not be successful.

We thank the community for supporting our efforts to develop RG6206 and are especially grateful to the individuals and families who participated in our clinical studies for RG6206. We sincerely thank you for your time, your partnership, and your unwavering commitment to research.

Data from the phase 2/3 SPITFIRE study interim analysis will be presented at upcoming congresses, and additional data about RG6206 will be shared with the scientific and patient communities over the coming months in order to contribute to the broader community’s efforts to develop new treatment options for people with this condition.

Roche and Genentech will also continue to partner with the global Duchenne community on ongoing projects, including with World Duchenne Organization on its Psychosocial Program as well as its data-sharing initiative. We will also be sharing our data for RG6206 with other consortia, for example, the collaborative Trajectory Analysis Project (cTAP) consortium.

Again, we are saddened to have to announce this decision and we share the community’s disappointment.

  • If you are a study participant or family member, we encourage you to reach out to your study physician for more information and detailed next steps.
  • For more information or questions about the study or study sites, you can also reach out to us via email at or by phone at (888) 662-6728.


Eydith Comenencia Ortiz and Elena Zhuravleva, on behalf of the Roche and Genentech Global Duchenne Team

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