TransCon PTH Shows 82% Responder Rate and 9.4 mL/min eGFR Gain Over Five Years
ASND•TransCon PTH sustained an 82% multi-component responder rate through five years, with 96% independence from active vitamin D and 95% independence from calcium in hypoparathyroidism patients. Mean eGFR rose by 9.4 mL/min/1.73 m2 and serum calcium normalized in 88% of patients, with quality-of-life and BMD improvements maintained.
1. Sustained Efficacy Over Five Years
At Week 266, TransCon PTH achieved an 82% responder rate for the composite endpoint of normocalcemia, no active vitamin D and ≤600 mg/day calcium. Serum calcium levels normalized in 88% of patients with a mean value of 9.0 mg/dL, and quality-of-life scores remained in the normative range through five years.
2. Independence From Conventional Therapy
By five years, 96% of patients achieved independence from active vitamin D (no calcitriol or alfacalcidol) and 95% achieved independence from therapeutic doses of calcium (<600 mg/day), eliminating the need for conventional supplementation.
3. Multi-Organ Benefits
Mean eGFR improved by 9.4 mL/min/1.73 m2 from baseline to 78.0 mL/min/1.73 m2, contrasting with expected age-related decline. Urine calcium normalized within 26 weeks and stayed stable, while bone mineral density Z-scores remained above baseline and SF-36 scores indicated sustained health-related quality-of-life improvements.
4. Safety and Immunogenicity
TransCon PTH was well tolerated over five years, with mostly mild or moderate adverse events and no drug-related discontinuations. One patient developed transient, low-titer non-neutralizing anti-PTH antibodies without any impact on safety or efficacy.
