Enanta Pharmaceuticals, Inc. · NASDAQ:ENTA

Enanta Pharmaceuticals — ATS 2026 International Conference

14 slides from Enanta Pharmaceuticals's conference presentation, May 2026

  1. Slide 1: Zelicapavir Reduces Symptom Duration and Hospitalization in a Phase 2 Trial

    Zelicapavir Reduces Symptom Duration and Hospitalization in a Randomized, Double-Blind, Placebo-Controlled, International Phase 2 Trial C. Harris, J. DeVincenzo, S. Chen, T. Ngo, A. Ahmad, M. Turnak, S. Rottinghaus Enanta Pharmaceuticals, Inc. - Watertown, Massachusetts (United States) ATS 2026 Inte

  2. Slide 2: Disclosure to Learners

    Disclosure to Learners Financial Relationships with “ineligible companies” within the past 24 months: Company name, type of relationship: Enanta Pharmaceuticals, Employee, Stock holder Vertex Pharmaceuticals, Former Employee, Stock holder

  3. Slide 3: Zelicapavir (EDP-938): N-Protein Inhibitor for RSV

    Zelicapavir (EDP-938): N-Protein Inhibitor for RSV • N-inhibitor in clinical development for RSV – Replication inhibitor: shuts down the production of new RSV virions (vs. fusion inhibitors that block viral entry) • Granted Fast Track designation by the FDA • Strong preclinical profile – Nanomolar p

  4. Slide 4: Respiratory Syncytial Virus Disease: Effects in CHF and COPD Patients

    Respiratory Syncytial Virus Disease: Effects in CHF and COPD Patients • Congestive Heart Failure • Chronic Obstructive Pulmonary Disease – A recent study showed that, among those with – A case-control study of 11887 patients RSV infection, CHF hospitalizations were showed that RSV hospitalization wa

  5. Slide 5: Zelicapavir Phase 2b RSV High-Risk Adult Study: Design & Objectives

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Design & Objectives Double-Blind Treatment Phase 5 days 186 adults with at least • Primary Objective: one of the following: Placebo (QD) Time to resolution** of RSV • COPD 28 Day Follow-up LRTD symptoms (RiiQTM • Congestive heart failure Zelicapavir •

  6. Slide 6: Phase 2b Baseline Characteristics (Safety & HR3 Population)

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Baseline Characteristics (Safety & HR3 Population) • Baseline characteristics were balanced across treatment groups • Majority of patients (~2/3) enrolled within 48 hours of symptom onset prior to randomization Safety Population HR3 Population* Zelicap

  7. Slide 7: Phase 2b RSV High-Risk Adult Study: Favorable Safety Profile

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Favorable Safety Profile • Adverse events (AEs) were similar between zelicapavir dosing groups and placebo • No AEs led to treatment discontinuation or study withdrawal in zelicapavir group Zelicapavir Placebo Description, n (%) (N=121) (N=65) Treatmen

  8. Slide 8: Faster Time to Complete Symptom Resolution Across Multiple RiiQ Measures

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Faster Time to Complete Symptom Resolution Across Multiple RiiQ Measures Efficacy Population HR3 Population* 20 7.2d (34%) 18 Placebo 3.6d 6.7d (19%) (35%) 16 Zelicapavir symptom resolution by RiiQ 2.2d Median days to complete 14 (14%) 3.0d (20%) 12 0.

  9. Slide 9: Time to Complete Resolution of All RSV Symptoms: CHF and COPD

    Time to Complete Resolution of All RSV Symptoms: CHF and COPD (Efficacy Population) • Faster time to complete resolution of all RSV symptoms in CHF and COPD populations CHF COPD Zelicapavir Placebo Zelicapavir Placebo (n=26) (n=8) (n=43) (n=24) Complete Resolution of All RSV Symptoms Resolved – n (%

  10. Slide 10: Symptom Summary for Zelicapavir Compared to Placebo

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Symptom Summary for Zelicapavir Compared to Placebo Symptoms Measured by RiiQ • Faster time to complete resolution of all RSV symptoms to absent – Symptom reduction of ~one week in the HR3 population for all 13 RSV symptoms and total RiiQ – Time to com

  11. Slide 11: Hospitalization and Death Endpoints

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Hospitalization and Death Endpoints • Lower hospitalizations for patients treated with zelicapavir Zelicapavir Placebo All-cause-hospitalizations 1.7% (2/115) 5.0% (3/60) RSV-associated hospitalizations • Blinded investigator attribution 0% (0/115) 5.0

  12. Slide 12: Virology Results for Zelicapavir Compared to Placebo

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Virology Results for Zelicapavir Compared to Placebo • Larger viral load decline at end of treatment (Day 5) RSV PCR viral load decline of 0.7 log for HR3 – Efficacy Population: 0.6 log population at the end of treatment – HR3 population: 0.7 log • Gre

  13. Slide 13: Pharmacokinetics

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Pharmacokinetics • Zelicapavir target exposures were achieved and were consistent with exposures observed in previously treated subjects • Mean predose (Ctrough) concentrations were 1100 and 1141 ng/mL on Days 3 and 5, respectively Visit n Mean % CV Da

  14. Slide 14: Phase 2b RSV High-Risk Adult Study: Conclusions

    Zelicapavir Phase 2b RSV High-Risk Adult Study: Conclusions • Zelicapavir demonstrated compelling results on multiple clinically meaningful endpoints measuring different aspects of RSV disease  Up to one week improvement in complete symptom resolution in the HR3 population  3.5 to 7.4 day symptom

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