Is New Type 1 SMA Treatment in Sight?

On April 24, at the 2018 American Academy of Neurology Annual Meeting, preliminary data was released from Part 1 of the ongoing FIREFISH clinical trial monitoring the dose-finding portion of RG7916 for patients with Type 1 spinal muscular atrophy (SMA). RG7916 is currently being developed by Roche and Genentech in collaboration with PTC Therapeutics, Inc and the SMA Foundation.

The trial has shown that RG7916, at all dose levels, has been well tolerated and there have been no drug-related safety findings leading to withdrawal to date. Additionally, since the study’s initiation, no babies have lost the ability to swallow, and none have required a tracheostomy or permanent ventilation. Participating babies have received RG7916 for a duration of up to 14.8 months, and 6.7 months was the median age of the first dose.¹

Dr Giovanni Baranello, Fondazione Istituto Neurologico Carlo Besta in Milan, Italy, stressed the data’s significance. "SMA Type 1 is a devastating disease in which babies rarely live past the second year of life without permanent nutritional and/or ventilatory support. This early data on the infants' ability to swallow and lack of need of permanent ventilatory support is very encouraging."

RG7916 is a splicing modifier that changes the way the pre-mRNA is spliced, causing the full-length SMN mRNA to be produced, thus enabling it to encode for functional SMN proteins.²

SMA is a genetic neuromuscular disorder and is the leading cause of mortality in infants and toddlers. It is caused by a missing or defective survival of motor neuron 1 (SMN1) gene, which results in reduced levels of the SMN protein.

FIREFISH, an ongoing, global multi-center, open-label, seamless Phase 2 study, is assessing RG7916’s efficacy and safety in babies with Type 1 SMA and two SMN2 gene copies aged 1—7 months at enrollment. Based on data from 21 patients from the completed Part 1 portion, RG7916 is suggested to produce a dose-dependent increase in SMN protein levels in babies with Type 1 SMA.

Stuart W. Peltz, PhD, Chief Executive Officer of PTC Therapeutics, expressed his content with the drug’s performance thus far. “RG7916 continues to demonstrate compelling results in SMA patients and we look forward to making further gains to combat this devastating, fatal disease. We are encouraged by this promising data as we continue our ongoing global recruitment efforts for the SMA programs."

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References:

1. Preliminary Clinical Data from FIREFISH Trial in Type 1 SMA Patients Presented at the American Academy of Neurology Annual Meeting. prnewswire.com/news-releases/preliminary-clinical-data-from-firefish-trial-in-type-1-sma-patients-presented-at-the-american-academy-of-neurology-annual-meeting-300635946.html. Accessed April 25, 2018.
2. RG7916. smanewstoday.com/rg7916-rg7800-roche-ptc-smaf. Accessed April 25, 2018.