Company Overview - Enanta is a virology and immunology company with a historical focus on hepatitis C, having developed two products in collaboration with AbbVie, including glecaprevir, which is part of the hepatitis C drug MAVYRET that has cured over 1 million patients with chronic hepatitis C [3]. Current Focus - The company has expanded its focus beyond liver virology to respiratory virology, with respiratory syncytial virus (RSV) as its first target, addressing a significant unmet medical need as no safe and effective treatment has been developed for this virus despite its characterization over six decades [4].

Enanta Pharmaceuticals FY Conference Summary Company Overview - Enanta Pharmaceuticals is a virology and immunology company with a history in hepatitis C, having developed the drug Glecaprevir, part of Mavyret, which has cured over a million patients with chronic hepatitis C [2][3] - The company has expanded its focus to respiratory virology, particularly targeting respiratory syncytial virus (RSV) and has also branched into immunology with new programs [2][3] Key Programs and Developments Respiratory Syncytial Virus (RSV) - RSV has a significant unmet medical need, with no safe and effective treatments available despite its long history [3] - In the 2024-25 RSV season, there were approximately 6.5 million outpatient visits, hundreds of thousands of hospitalizations, and tens of thousands of deaths in the U.S. [4] - Vaccination rates for RSV are low, with only about 20% of the eligible population vaccinated [5] - Enanta's lead asset, Ziresovir, has shown promising results in two Phase 2 studies, particularly in high-risk populations, including adults over 65 and those with comorbidities [6][9] - Ziresovir reduced the time to complete resolution of symptoms by about one week compared to placebo and lowered hospitalization rates from 5% to 1% [9] - The company is preparing for a Phase 3 study of Ziresovir and is in discussions with the FDA regarding the study design [24] Immunology Programs - Enanta has initiated several immunology programs, including: - **EDP-978**: A KIT inhibitor aimed at mast cell-driven diseases, with an IND filing expected in Q1 2026 [13][25] - **EDP-3903**: A STAT6 inhibitor designed to provide an oral alternative to Dupixent, with an IND filing planned for the second half of 2026 [15][25] - **X2 Program**: Targeting mast cell activation, with a development candidate expected in the second half of 2026 [20][25] Competitive Landscape and Strategic Considerations - Enanta is exploring business development opportunities in the RSV field and is considering partnerships for commercialization [25][27] - The company aims to maintain its leadership position in the RSV treatment space, especially as competitors have faced setbacks [27][28] - The potential for combination therapies using EDP-323 and Ziresovir is being evaluated for severely immune-compromised patients [30] Additional Insights - The company emphasizes the importance of maintaining drug concentrations above the effective threshold to ensure efficacy, particularly in the context of viral infections [32] - Enanta's approach to drug development focuses on small molecule inhibitors, which offer predictable dosing and pharmacokinetic properties [19][38] - The X2 program has potential applications beyond mast cell-driven diseases, including conditions like migraines due to its expression on peripheral neurons [37][38] Conclusion - Enanta Pharmaceuticals is positioned to address significant unmet needs in both virology and immunology, with promising data from ongoing studies and a strategic focus on maintaining leadership in the RSV treatment landscape [25][27]