Over the past few years, there has been an increase in the number of pharmaceutical companies developing FSHD therapeutics. These strategies primarily focus on blocking DUX4, the toxic element that causes FSHD. These treatments are considered “disease modifying” because they target the root cause of the disease, and if effective, would stop the disease from progressing and becoming more debilitating.

People with FSHD have testified that stopping the disease from progressing is the highest priority. But for the next generation of therapies, strategies are being developed to address the loss of muscle tissue and function. Although this goal was once considered a long shot, there are now several approaches that aim to increase and possibly recover loss of muscle mass, which, if paired with disease-modifying drugs, could in turn reverse the impact of FSHD.

One of these approaches is to boost growth of the existing muscle. This should increase strength and extend functional use of the muscle over the course of the disease. There have already been several trials for this approach in FSHD which have generated mixed results. These include a trial of MYO- 029 by Wyeth Pharmaceuticals in 20082 and of ACE-083 by Acceleron Pharmaceuticals that concluded in 2019.