Enanta Pharmaceuticals Announces Positive Topline Results from First-in-Pediatrics Phase 2 Study Evaluating Zelicapavir for the Treatment of Respiratory Syncytial Virus (RSV)

About this update from Enanta Pharmaceuticals, Inc.

Observed an antiviral effect for the primary and secondary virology endpoints in the overall population, with a viral load decline of 1.4 log at the end of treatment in Part 2 Demonstrated a viral load decline of 1.2 log compared to placebo at the end of treatment in prespecified analysis of patients randomized within 3 days of symptom onset Zelicapavir was well-tolerated with a favorable safety profile Conference call and webcast to discuss data at 8:30 a.m. ET today WATERTOWN, Mass. --(BUSINESS WIRE)-- Enanta Pharmaceuticals, Inc. (NASDAQ:ENTA), a clinical-stage biotechnology company dedicated to creating small molecule drugs for virology and immunology indications, today announced positive topline results from the first-in-pediatrics Phase 2 study evaluating zelicapavir in hospitalized and non-hospitalized children aged 28 days to 36 months with respiratory syncytial virus (RSV). An antiviral effect was observed for the primary and secondary virology endpoints in the overall pooled efficacy population. The primary endpoint in Part 2 of the study, which focused on virology, showed a pronounced antiviral effect with a 1.4 log decline in viral load at Day 5 compared to placebo. Additionally, a rapid and robust virologic effect was observed in a prespecified subset of patients who were randomized within 3 days of symptom onset, with a 1.2 log decline in viral load at Day 5 compared to placebo. The study also showed that zelicapavir demonstrated a favorable safety profile and was well-tolerated in this pediatric population. Zelicapavir, which received Fast Track designation from the U.S. Food and Drug Administration (FDA), is a novel N-protein inhibitor in development as a once-daily oral treatment for RSV. “We are excited to share these positive results from our first-in-pediatric Phase 2 study of zelicapavir, which we believe confirm a strong profile for our lead RSV antiviral and strengthen Enanta’s position as a leader in developing treatments for RSV. Zelicapavir demonstrated an antiviral effect on both primary endpoints, as well as secondary virology endpoints. Furthermore, patients who joined the study within 3 days of symptom onset showed a robust 1.2 log reduction in viral load at Day 5. These data provide us with continued confidence in zelicapavir and valuable insights to inform the design of a potential registration enabling trial,” said Scott T. Rottinghaus , M.D., Chief Medical Officer of Enanta Pharmaceuticals . “There is a substantial need for safe and effective oral treatments for RSV, and we believe that these important antiviral data along with the favorable safety profile observed in this young, vulnerable population support further clinical evaluation of zelicapavir.” “In my practice, I see many children requiring hospitalization for severe RSV infection during the RSV season. The impact of RSV is felt not only by patients and caregivers, but also broadly by public health. I believe that a safe and effective antiviral therapeutic is critical in addressing this significant and unmet need,” said Jaime Deville , MD, FAAP, a Principal Investigator in the Phase 2 pediatric clinical trial of zelicapavir and Professor of Clinical Infectious Diseases in the Department of Pediatrics at the David Geffen School of Medicine , University of California, Los Angeles and UCLA Mattel Children’s Hospital. “These results support further evaluation of zelicapavir and suggest the potential for zelicapavir to improve patient outcomes. I’m excited to see this compound move forward, to possibly deliver the first safe and effective antiviral to treat children with RSV infection.” Zelicapavir Phase 2 Study Topline Results This Phase 2 study was a randomized, double-blind, dose ranging, placebo-controlled study in hospitalized and non-hospitalized pediatric patients with RSV aged 28 days to 36 months. The primary objective of Part 1 of the study was to evaluate the safety and pharmacokinetics of zelicapavir and to determine the optimal dosing for Part 2 of the study. The primary objective of Part 2 of the study was to evaluate the antiviral activity of zelicapavir, with assessment of symptom severity as an exploratory objective. Because exposure was similar across all cohorts and doses, and all patients received a therapeutic dose, primary efficacy analyses were able to be performed across all dosed patients from Parts 1 and 2. A total of 96 patients received zelicapavir (n=70) or placebo (n=26). Part 1 evaluated multiple doses and patients were treated with zelicapavir (n=36) or placebo (n=16) once-daily (QD) for 5 days. In Part 2, patients received the selected dose of zelicapavir (n=34) or placebo (n=10) QD for 5 days. Demographics and baseline characteristics were balanced across treatment groups, with the majority of patients being hospitalized at enrollment, and a mean duration of RSV symptoms prior to randomization of 4 days. Zelicapavir demonstrated a favorable safety profile over the initial 5-day dosing period and through 23 days of follow-up. Adverse events (AEs) were similar between zelicapavir and placebo and there were no AEs leading to treatment discontinuation or study withdrawal. Furthermore, zelicapavir achieved target drug exposure levels across all age groups and dosing cohorts. Exposure was similar across cohorts and doses, and all patients received a therapeutic dose. A dose of 5 mg/kg was selected for age ≥ 28 days to

View stock analysis, news, and events for Enanta Pharmaceuticals, Inc.