PTC Therapeutics (PTCT) Q1 FY26 earnings call: guidance and Q&A

PTC Therapeutics reported a record quarter for product revenue, largely driven by the continued strong global launch of Sephience. Global revenue for Sephience was $125 million, a 36% sequential increase, with U.S. revenue contributing $112 million. The company has achieved 1,244 commercial patients globally as of March 31, 2026, and surpassed 1,500 U.S. patient starts, maintaining a consistent cadence of approximately 140 new prescriptions per month. The launch demonstrates broad adoption across age groups, disease severities, and treatment histories, with over 90% of U.S. PKU centers of excellence now prescribing Sephience, and low double-digit discontinuation rates.

The company announced positive top-line results from the 24-month interim analysis of the PIVOT-HD long-term extension study for votoplam. The data showed a dose-dependent slowing of disease progression on cUHDRS, with an average slowing of 52% relative to a matched natural history cohort at the 10-milligram dose level in participants with Stage 2 disease. The safety profile remained favorable across all doses and disease stages, increasing confidence in the ongoing global Phase III INVEST-HD study, which is funded and led by partner Novartis and targets 770 individuals with early symptomatic disease.

Following a Type C meeting with the FDA in April, PTC Therapeutics is moving forward with an open-label study for vatiquinone to support an NDA resubmission. The study will enroll approximately 120 individuals with Friedreich's ataxia aged 7 to 21, utilizing a matched natural history control group from the FACOMS disease registry. The primary endpoint will be the change in mFARS from baseline to 24 months, with the company expressing confidence in the study design's increased probability of success, leveraging learnings from previous studies and the well-characterized natural history of FA.

PTC Therapeutics is advancing its earlier-stage pipeline, with plans to initiate a Phase I study for PTC612, an oral NLRP3 inhibitor, in the second quarter of 2026. This study will include a dosing cohort with elevated inflammatory biomarkers to assess PK/PD. Additionally, good progress is being made on the wholly owned MSH3 oral splicing program for Huntington's disease and DM1, which could complement the votoplam program, and several programs from the Inflammation and Ferroptosis platform, including the Phase II-ready PTC844 DHODH program.

The Duchenne Muscular Dystrophy (DMD) franchise delivered solid performance despite significant headwinds. Translarna revenue was $59 million, boosted by a large one-time^📎 government purchase order in Brazil. Emflaza generated $22 million in quarterly revenue, supported by strong brand loyalty and high-touch patient services, even amidst multi-generic erosion with 10 generics now in the market. The company acknowledges the uncertainty in predicting the longevity of Translarna's European business without a license and expects continued erosion for Emflaza.

U.S. payer dynamics for Sephience remain favorable, with most commercial and government policies in place, covering over two-thirds of the U.S. population with limited restrictions. Prior authorizations are typically based on label requirements and are processed efficiently, leading to improved time from prescription to dispense. Internationally, Japan's pricing and reimbursement are finalized and locked for 10 years, while European markets are actively reviewing health technology assessment dossiers, with pricing negotiations expected to conclude in late 2026 or early 2027. The company aims for commercial sales in up to 30 countries by year-end.