Enanta Pharmaceuticals, Inc.

What they do

Enanta uses chemistry-driven drug discovery to develop small molecule drugs for virology and immunology. Its only marketed product exposure is the HCV protease inhibitor glecaprevir, which it discovered and out-licensed to AbbVie and which is sold as part of MAVYRET (U.S.)/MAVIRET (ex-U.S.). Its active pipeline includes zelicapavir for RSV, clinical programs for SARS-CoV-2 and HBV, and oral immunology candidates targeting KIT and STAT6 for type 2 inflammatory diseases such as urticaria and atopic dermatitis.

Revenue drivers

• HCV royalty revenue from AbbVie — Essentially all reported revenue is royalty revenue on worldwide net sales of AbbVie's MAVYRET/MAVIRET (glecaprevir/pibrentasvir) HCV regimen. Revenue has declined every year from $97.1M in 2021 to $65.3M in 2025, and was $14.4M in the quarter ended June 30, 2026.
• Retained portion of HCV royalties — Under a royalty sale transaction with OMERS affecting royalties earned after June 2023, 54.5% of ongoing MAVYRET/MAVIRET royalty revenue is paid to OMERS, capped at 1.42 times the $200.0M purchase price, through June 30, 2032. After the cap is reached, Enanta retains 100% of the cash royalty payments.
• Clinical-stage pipeline (no current revenue) — Zelicapavir for RSV, EDP-978 (KIT inhibitor) for urticaria, EPS-3903 (STAT6 inhibitor), and an MRGPRX2 program are in development and generate no revenue. Management aims for zelicapavir to become the first approved antiviral treatment for RSV.

Recent performance

Total revenue for the quarter ended June 30, 2026 was $14.4 million, all from MAVYRET/MAVIRET royalties, down from $18.3 million in the same quarter of 2025. The decline was primarily attributable to AbbVie's lower reported HCV sales. R&D expense was $22.1 million versus $27.2 million a year earlier, reflecting lower RSV clinical trial costs partly offset by higher immunology spending, and G&A was $9.5 million versus $10.0 million. Interest expense rose to $4.1 million from $1.6 million due to increased forecasted royalty revenue, and operating cash flow improved to -$19.3 million for fiscal 2025 from -$78.8 million in fiscal 2024.

Strategy

Enanta is prioritizing clinical execution in RSV and immunology while its HCV royalty stream funds operations. Dosing has begun in LOTUS, a Phase 2b pediatric trial of zelicapavir in Thailand, with topline data expected in 2027. The company plans to initiate RESOLVE, a registrational Phase 2b/3 trial of zelicapavir in high-risk adults, in the fourth quarter of 2026. In immunology, it expects topline Phase 1 data for EDP-978 in urticaria in the fourth quarter of 2026, to file an IND for EPS-3903 and select an MRGPRX2 development candidate in the second half of 2026.

Risks

• Concentrated royalty dependence — Substantially all revenue comes from a single royalty stream on AbbVie's MAVYRET/MAVIRET, which has declined annually from $97.1M in 2021 to $65.3M in 2025.
• Ongoing operating losses — Enanta has recorded annual net losses every year from 2021 through 2025, including a $81.9M net loss in fiscal 2025, and expects to continue incurring losses while its pipeline remains pre-approval.
• Third-party clinical and regulatory risk — The pipeline value depends on zelicapavir and immunology candidates succeeding in trials; management notes no approved antiviral therapies currently exist for RSV, and development is subject to risks and uncertainties that could delay or prevent approval.
• OMERS royalty obligation — 54.5% of MAVYRET/MAVIRET royalty cash is paid to OMERS through June 30, 2032, subject to a 1.42x cap on the $200.0M purchase price, reducing near-term cash retained from the royalty stream.

Outlook

Management states that as of June 30, 2026 it had $211.5 million in cash and marketable securities plus continuing retained royalties, with a cash runway expected to fund operations into fiscal 2029. The company targets initiation of the registrational RESOLVE trial in high-risk adults with RSV in the fourth quarter of 2026, with Phase 2b topline data expected in 2027 and LOTUS pediatric topline data also expected in 2027. Immunology catalysts include Phase 1 topline data for EDP-978 in the fourth quarter of 2026, an IND filing for EPS-3903, and selection of an MRGPRX2 development candidate in the second half of 2026.