Versartis Reports Data from Up to 30 Mos. of Somavaratan Treatment for Pediatric Growth Hormone Deficiency

Versartis, Inc.

, an endocrine-focused biopharmaceutical company that is developing somavaratan (VRS-317), a novel, long-acting form of recombinant human growth hormone (rhGH) for growth hormone deficiency (GHD), today announced that efficacy, safety, and adherence data from up to 30 months of somavaratan treatment in the Phase 2a trial and VISTA long-term safety study for pediatric GHD were presented during the 55th Annual Meeting of the European Society of Paediatric Endocrinology (ESPE). The meeting was held September 10-12, 2016, in Paris. "We are pleased to see that the safety profile of somavaratan has been maintained with 30 months of treatment in the VISTA study, and that dosing compliance, which is critical for children to achieve their final target height, was still robust after 24 months of at-home administration," said Bradley S. Miller, M.D., Ph.D., Associate Professor in the Department of Pediatric Endocrinology at the University of Minnesota Masonic Children's Hospital and a study investigator. "Height velocity in Year 2 at the current Phase 3 dose was as good as or better than our available benchmarks, so we look forward to the outcome of the Phase 3 VELOCITY trial around this time next year." In an oral presentation entitled, "Somavaratan (VRS-317) Treatment for Pediatric Growth Hormone Deficiency (GHD): Results at 2.5 Years," Dr. Miller reviewed efficacy and safety results from the Phase 2a clinical trial of somavaratan in treatment-naive, pre-pubertal GHD children (months 0-6 of treatment) and the subsequent VISTA study (Versartis Long-Term Safety Study of Somavaratan). The somavaratan dose increased during the VISTA study to 3.5 mg/kg of somavaratan twice-monthly (the dose currently being evaluated in Phase 3). Results suggest that somavaratan was safe and well tolerated through 30 months of drug exposure and at the Phase 3 dose, Year 2 Height Velocity (HV) was comparable to estimates from similar patients in the NCGS database of rhGH daily dosing in the US: Among the 57 patients evaluable for the Year 2 efficacy analysis, mean HV after the dose increase was comparable from Years 1 to 2 (8.1±2.2 vs. 7.8±2.3 cm/year), and mean height SDS continued to improve (-2.1±0.6 vs. -1.6±0.7). Catch up growth over the 2 year period was supported by mean bone age (BA) advancing by 2.4 years and mean height age by 2.7 years. The difference in mean years between chronological age and BA decreased over the course of the study: 1.5±0.8 at screening, 1.4±0.9 at Year 1, and 1.0±1.0 at Year 2. The frequency of Adverse Events (AEs) declined substantially after the initial 6 month exposure period, and the Phase 3 dose was safe and well tolerated in this study. Additionally, Eric Humphriss, Vice President of Global Clinical Operations at Versartis, presented a poster entitled, "Adherence with Twice-Monthly, At-Home Dosing Schedule of Somavaratan (VRS-317) Long-Acting Growth Hormone Treatment in Children with Growth Hormone Deficiency (GHD)." An estimated 66%–77% of adults and children with GHD are noncompliant with daily rhGH injections, and this has been associated with reduced annual HV. Somavaratan was designed to reduce injection burden for patients and a twice-monthly dosing schedule is currently being evaluated in Phase 3. In this VISTA study analysis, somavaratan was administered at-home and treatment adherence was recorded by caregivers using an electronic patient-reported outcome diary (eDiary; Bracket, Inc.). Following 24 months of at-home dosing and over 2200 doses at the current Phase 3 dose, treatment adherence rate was 99.6%. These data suggest that a twice-monthly dosing regimen has the potential to improve treatment adherence and associated outcomes.