PTC Therapeutics, Inc. announced the presentation of early interim data from Part 1, the dose-finding portion of the FIREFISH study. FIREFISH is a two-part seamless, open-label, multi-center study to investigate the safety and efficacy of RG7916 in infants and babies with Type 1 SMA. RG7916 has been safe and well tolerated at all doses and there have been no drug-related safety findings leads to withdrawal. In addition, data on the ability to swallow and requirements for tracheostomy or permanent ventilation, together with overall survival were also presented. Previously published natural history data indicate that in a comparable historic cohort the median age of event-free survival for SMA Type 1 infants to be between 8 and 10.5 months. FIREFISH (NCT02913482) is a multi-center, open-label, seamless pivotal study evaluating the safety and efficacy of RG7916 in babies aged 1–7 months at enrollment with Type 1 SMA and two SMN2 gene copies. The exploratory Part 1 (n=8–24) is assessing the safety, tolerability, pharmacokinetics and pharmacodynamics of RG7916 at different dose levels. In Part 1, patients receive RG7916 for at least 4 weeks (or 2 weeks after steady-state is achieved) of daily administration; patients then enter an extension phase with RG7916. The confirmatory Part 2 (n=40) will assess the safety and efficacy of RG7916 at the dose level selected from Part 1 over 24 months. The primary endpoint for Part 2 is the proportion of infants sitting without support for 5 seconds, assessed by the Gross Motor Scale of the BSID-III, after 12 months of treatment. In addition to the oral presentation, three posters were on display during the Congress: updated pharmacodynamic and safety data from SUNFISH Part 1, preliminary evidence for pharmacodynamic effects of RG7916 in JEWELFISH, and preclinical data demonstrating the relationship between central and peripheral SMN protein increase upon treatment with RG7916. The data presented demonstrate systemic and dose-dependent increase of SMN protein levels. The data from mice and other species suggest that SMN protein level increases seen in the blood of patients following RG7916 treatment reflect SMN protein level increases in the CNS, muscle and other key issues affected in SMA. In addition, RG7916 has been safe and well tolerated at all doses and there have been no drug-related safety findings leads to withdrawal. The U.S. Food and Drug Administration granted orphan drug designation to RG7916 for the treatment of patients with SMA. RG7916 directly targets the underlying molecular deficiency of SMA by modulating SMN2 splicing to increase expression of full-length SMN2 mRNA from the SMN2 gene. An interim analysis from the first part of SUNFISH of the five cohorts treated with RG7916 for 28 days or longer demonstrated an exposure-dependent increase in SMN protein. SMA is characterized by reduced levels of SMN protein, motor neuron loss, and muscle atrophy. To date, RG7916 remains well-tolerated in patients at all doses and there have been no drug-related safety findings leads to withdrawal. The SMA program was initially developed by PTC Therapeutics in partnership with the SMA Foundation in 2006 to accelerate the development of a treatment for SMA. In November 2011, Roche gained an exclusive worldwide license to the PTC/SMA Foundation SMN2 alternative splicing program. The development of these compounds is being executed by Roche and overseen by a joint steering committee with members from PTC, Roche, and the SMA Foundation.