Design Therapeutics presented updates on its lead program DT-216 for Friedreich ataxia at the 12th Annual Cantor Fitzgerald Global Healthcare Conference on September 9, 2026. The company highlighted its biomarker push and discussed its pipeline programs, clinical data, and regulatory strategy.
DT-216 is a small molecule designed to recognize unique long GAA repeat sequences and dial up endogenous natural frataxin. The compound has been reengineered from the first-generation version to DT-216P2, establishing a new dose-to-exposure relationship. In a 4-week study, DT-216 demonstrated a clean safety profile and clinical proof of concept. Doses evaluated were 0.3 mg/kg, 0.6 mg/kg, and 1 mg/kg. Increased endogenous, fully spliced mature mRNA was observed in whole blood starting at 0.3 and 0.6 mg/kg, with a clear protein response seen at 1 mg/kg. Drug activity was also confirmed in muscle tissue via RNA measurements. Sustained frataxin protein elevation was noted 2 weeks after the last dose. Functional improvements were observed, with a 6.4-point improvement from baseline in the Modified Friedreich's Ataxia Rating Scale (mFARS) and a 2.7-point improvement in the Upright Stability Score (USS).
Future study plans include a registrational strategy with a primary efficacy endpoint of endogenous frataxin blood protein. The study will involve approximately 10 patients dosed at 1 mg/kg weekly for 12 weeks, with data expected in Q1 2027. A higher-dose cohort is also being explored to inform long-term development.
Design Therapeutics also presented updates on its DM1 program, DT-818. DT-818 is designed to recognize long CTG repeats in the DMPK gene and reduce toxic RNA production at the DNA level. Preclinical and cell findings demonstrated over 90% elimination of toxic RNA in patient-derived cell systems, working similarly across very long repeats (2,600 repeats) and shorter repeats (330 repeats). The program is currently in a multiple ascending dose (MAD) study, with data expected in 2027.
The company also mentioned its Fuchs' Corneal Dystrophy program, with data expected in 2026, and its Huntington’s Disease program, which is in the preclinical stage.
Design Therapeutics is supported by a natural history dataset covering over 600 individuals worldwide with Friedreich ataxia, with up to 10 years of follow-up. The dataset links very long GAA repeats to very low frataxin and early onset, while higher frataxin levels correlate with later onset and delayed loss of ambulation/wheelchair dependence. The company is engaging with the FDA to test whether endogenous blood protein can serve as a reasonably likely surrogate endpoint to support an accelerated approval framework. A regulatory update on registrational plans is expected in Q4 2026.
