PTC Therapeutics Announces Initiation of FIREFISH Study in Infant (Type I) SMA Patients

SOUTH PLAINFIELD, N.J., January 5, 2017 – PTC Therapeutics, Inc. (NASDAQ: PTCT) today announced that its joint development program in Spinal Muscular Atrophy (SMA) with Roche and the SMA Foundation (SMAF) initiated a clinical study in infants with Type I SMA. The study, named FIREFISH, will investigate the safety, tolerability and efficacy of RG7916 in babies aged 1 to 7 months. RG7916 is an oral small molecule splicing modifier that directly targets the underlying molecular deficiency of SMA by modulating SMN2 splicing to increase expression of stable full-length SMN protein from the SMN2 gene. SMA is a rare genetic disorder that results in neuromuscular disability beginning in infancy and is the leading inherited cause of mortality in infants and young children.

“In addition to the SUNFISH study, we are excited to initiate FIREFISH to investigate RG7916 in infants that have the more severe form of SMA,” said Stuart W. Peltz, Ph.D., Chief Executive Officer of PTC Therapeutics. “As an oral agent that targets all tissues and organs in the body, RG7916 has the potential to impact all aspects of the disease. We believe this is critical, especially in this vulnerable population.”

FIREFISH is a two-part study. Part one is an open-label, dose escalation study in at least 8 infants for a minimum of 4 weeks. The primary objective of part one is to assess the safety profile of RG7916 in infants and determine the dose for part two. Part two is an open-label, single-arm study in approximately 40 infants with Type I SMA for 24 months, followed by an open-label extension. The primary objective of part two is to assess the efficacy of RG7916 at the selected dose over a 12-month treatment period. A trial in childhood onset (Type II/III) SMA patients, SUNFISH, is currently enrolling the dose escalation portion of the study. Commencement of the pivotal portion of either study will trigger a $20 million milestone payment to PTC from Roche.

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.