HP&M Attorney Mark Tobolowsky Co-Authors Article in Human Gene Therapy Advocating for the Acceptance of Microdystrophin Expression in DMD Patients as a Surrogate Endpoint for Accelerated Approval

March 19, 2023

Hyman, Phelps & McNamara, P.C.’s Mark Tobolowsky co-authored the peer-reviewed article “Microdystrophin Expression as a Surrogate Endpoint for Duchenne Muscular Dystrophy Clinical Trials” in the recently published edition of Human Gene Therapy.  The article arose out of work conducted by the Pathway Development Consortium, a partnership between stakeholders in the AAV gene therapy space.

The article describes the challenges facing development of AAV gene therapy treatments for Duchenne Muscular Dystrophy, a serious and life-threatening condition.  In particular, as the gene encoding the full-length dystrophin protein is too large to fit inside a single AAV vector used to deliver genes to human cells, development has focused on designing shortened versions of the dystrophin gene, known as microdystrophins, that can fit inside the AAV vector and retain the primary functionality of the full-length dystrophin protein.  The article describes the evidence supporting microdystrophin expression as a reasonably likely predictor of clinical benefit from AAV DMD gene therapy treatment and advocates for the use of accelerated approval for such therapies, as appropriate.