Ascendis Pharma announces topline results from Week 52 of COACH trial

Ascendis Pharma (ASND) announced topline results from Week 52 of COACH, the first Phase 2 clinical trial to evaluate combination therapy with once-weekly TransCon CNP and once-weekly TransCon hGH in children with achondroplasia. At Week 52, combination therapy showed durable growth without compromising safety or tolerability. In addition, combination therapy demonstrated benefits beyond linear growth with improvements in body proportionality and arm span, aligning with the increase in linear growth. Safety and tolerability of combination therapy were consistent with those observed for monotherapies of TransCon CNP and TransCon hGH and was generally well-tolerated, with generally mild TEAEs. The combination data underscore the potential of TransCon CNP to become the backbone therapy for addressing the underlying biology of achondroplasia, with TransCon hGH providing complementary benefit. For the TransCon CNP treatment-naive cohort, mean annualized growth velocity was 8.80 cm/year, with an improvement in mean ACH height Z-score of +1.02 over 52 weeks, indicating a tripling of efficacy compared to TransCon CNP monotherapy. For the TransCon CNP-treated cohort, mean AGV was 8.42 cm/year, representing an increase from baseline at Week 52 of 3.28 cm/year, with an improvement in mean ACH height Z-score of +0.86, increasing from 1.28 to 2.15 over 52 weeks. After 52 weeks, children treated with combination therapy exceeded the 97th-percentile AGV of average-stature children. Children treated with TransCon CNP and TransCon hGH demonstrated improvements in body proportionality after 52 weeks, aligning with the increase in linear growth. Arm span of children treated with combination therapy improved beyond the 84th-percentile of children with achondroplasia at Week 52. Bone age remained consistent with chronological age at Week 52. Safety and tolerability were consistent with those observed for TransCon CNP and TransCon hGH monotherapies. Combination treatment was generally well-tolerated, with a low incidence of injection site reactions and generally mild TEAEs. All children completed 52 weeks of treatment and remain on therapy in the COACH Trial.