Diving into the Developmental Milestone Survey with Dan Gallo and Tessa Clarkson from Jaguar Gene Therapy

In this episode of the Phelan-McDermid Syndrome Podcast: Sharing Research, Progress, and Hope, Lauren is joined by Dan Gallo, Executive Vice President and Head of Clinical Development and Medical Affairs at Jaguar Gene Therapy, and Tessa Clarkson, Clinical Development Consultant at Jaguar Gene Therapy.They discuss Jaguar’s Developmental Milestone Survey, a study designed to better understand how people with Phelan-McDermid syndrome gain, lose, and potentially regain meaningful developmental skills. The goal is to identify developmental patterns that could help researchers measure meaningful treatment effects and inform future clinical trials—including potentially reducing the need for placebo-controlled designs.The conversation covers the survey’s scientific rationale, lessons from a similar approach in Rett syndrome, eligibility and participation, and why family participation is especially important as Jaguar prepares for discussions with the FDA about future JAG201 development.JAG201 update: As of August 21, 2026, Jaguar reported that Cohort 1 dosing in its Phase 1/2 trial was complete and Cohort 2 dose escalation was underway. Jaguar described early indications of clinical benefit across neurodevelopmental domains and an emerging safety profile with no treatment-related serious adverse events reported to date, while emphasizing that more follow-up and complete analysis are needed before conclusions can be drawn.Learn more about the Developmental Milestone Survey: pmscaregiverstudy.com