At the end of October, we attended the inaugural Neuromuscular Drug Development Summit. This new meeting brought together thought leaders from industry, academia, and the patient advocacy community to discuss scientific progress and issues affecting companies developing drugs for these mostly rare diseases.
Neuromuscular diseases — such as muscular dystrophies, motor neuron diseases, mitochondrial diseases, myopathies, and more — involve both central nervous system experts and muscle specialists. These conditions are individually rare, but as a group affect more than 250,000 patients in the United States. Treatment options for those affected are still limited. However, recent advancements in genetic testing, biomarker identification, and precision medicine approaches to treatment, including gene therapies, are greatly changing the prospects for helping such patients.
Excitement surrounding the approval and therapeutic impact of Spinraza (nusinersen) has particularly galvanized drug developers seeking to advance new neuromuscular disease therapies. The U.S Food and Drug Administration (FDA) approved Spinraza in December 2016 as the first treatment for spinal muscular atrophy (SMA). Spinraza addresses the underlying cause of motor neuron loss in these patients by increasing production of the survival motor neuron protein. In the clinical trials that led to Spinraza’s approval, half of the infants who were treated with the drug reached a major motor milestone compared to none of the children who received a placebo. In later-onset forms of the disease, the children on Spinraza experienced an improvement in their motor function, while those on placebo worsened over time. Spinraza’s development has been widely applauded. On October 17, the discoverers of the drug — C. Frank Bennett, head of research at Ionis Pharmaceuticals, and Adrian R. Krainer, St. Giles Foundation Professor at Cold Spring Harbor Laboratory — received a $3 million “Breakthrough Prize” (the “Oscars of Science”) for their role in discovering and developing Spinraza, which is now marketed by Biogen.
An important issue of discussion at the Summit, impacting the development of treatments for orphan neuromuscular diseases, was the small number of patients available for clinical trials. A few patient advocacy groups are taking an active role in helping to alleviate this problem, collaborating with pharmaceutical companies to promote clinical trials and to find trial participants. These groups are also calling for greater coordination between patients, drug developers, clinicians, and regulators to create consistency in the development and regulatory processes and to accelerate access to drugs, trials, and care.
Several talks at the Summit were devoted to novel therapeutics in development, and in particular to the early promise of gene therapies. Several diseases are being looked at in this context, including SMA, Duchenne Muscular Dystrophy (DMD), and X-Linked Myotubular Myopathy (XLMTM). Discussion focused on how payers will approach coverage and reimbursement of new therapies, both stand-alone approaches and combination therapies, given that many of these treatments may be a one-time event. Other discussion centered on the relative value of gene therapies compared to other, more traditional types of treatments for these diseases.