Neurogene negative reaction to competitor data ‘overblown,’ says William Blair

After Taysha Therapeutics (TSHA) reported updated results from the ongoing REVEAL Phase I/II trial of TSHA-102, an AAV9 gene therapy for the treatment of Rett syndrome, on Tuesday, June 18, at the 2024 International Rett Syndrome Foundation Rett Syndrome Scientific Meeting, William Blair notes that two serious adverse events, consisting of a grade 3 seizure that required hospitalization and grade 2 constipation, were reported in the second pediatric patient. The firm thinks Neurogene’s (NGNE) 24% slide in response to Taysha’s clinical data is “overblown” given that some clinical efficacy signals were observed, supporting the potential use of gene therapy for Rett syndrome. The firm argues that there are several fundamental differences between Neurogene’s and Taysha’s programs, including route of administration, dose, transgene, and duration of follow-up, that lead it to believe Neurogene could see greater clinical benefit compared to what has been reported with TSHA-120. The firm, which continues to view NGN-401 as “a potentially first-in-class and best-in-class gene therapy for Rett syndrome, reiterates an Outperform rating on Neurogene.