Enanta Pharmaceuticals (ENTA) Is Up 33.3% After Positive Phase 2b RSV Results Propel Zelicapavir Forward

• In late September 2025, Enanta Pharmaceuticals announced positive topline results from its Phase 2b trial of zelicapavir for treating respiratory syncytial virus (RSV) in high-risk adults, observing faster symptom resolution and a lower hospitalization rate despite not meeting the trial's primary endpoint.
• This proof-of-concept success provides the company with clear support to advance zelicapavir into Phase 3 development, potentially addressing significant unmet needs in the RSV market for vulnerable populations.
• We'll examine how the strong symptom improvement results from the Phase 2b RSV trial may impact Enanta's investment narrative.

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What Is Enanta Pharmaceuticals' Investment Narrative?

For anyone considering Enanta Pharmaceuticals, the investment thesis hinges on a belief that the company’s pipeline can create significant value, despite ongoing losses and a history of market underperformance. The positive Phase 2b results for zelicapavir in high-risk RSV patients mark an important shift, offering a fresh catalyst and potentially reducing near-term clinical development risk. This news arrives alongside a sizeable equity raise, which strengthens the balance sheet and may support further development. Previously, Enanta’s immediate risks centered on funding gaps, long product development cycles, and a need for clear clinical wins after years of losses. With recent trial results, one of the largest uncertainties around clinical progress has eased, for now, though the company still faces execution risks, competition in RSV, and the challenge of moving a candidate to market amid ongoing cash burn. The next major milestones are likely centered on advancing zelicapavir through Phase 3, FDA interactions, and keeping investor confidence during ongoing losses and recent management transitions. Yet, even with positive momentum, big setbacks remain a possibility as the company remains unprofitable and further clinical or regulatory hurdles could arise.

Our valuation report here indicates Enanta Pharmaceuticals may be undervalued.

Exploring Other Perspectives

The Simply Wall St Community’s two fair value estimates span from US$19.14 to a very large US$149.10, showing widely varied expectations. Despite recent clinical progress, execution risk and cash burn remain open questions affecting how the market could price upcoming milestones. Investor perspectives may differ, so reviewing alternative insights can be valuable.

Explore 2 other fair value estimates on Enanta Pharmaceuticals - why the stock might be a potential multi-bagger!

Build Your Own Enanta Pharmaceuticals Narrative

Disagree with this assessment? Create your own narrative in under 3 minutes - extraordinary investment returns rarely come from following the herd.

• A great starting point for your Enanta Pharmaceuticals research is our analysis highlighting 2 key rewards and 2 important warning signs that could impact your investment decision.
• Our free Enanta Pharmaceuticals research report provides a comprehensive fundamental analysis summarized in a single visual - the Snowflake - making it easy to evaluate Enanta Pharmaceuticals' overall financial health at a glance.

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This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.

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