FDA Regulatory Decisions Expected for Three Drug Firms

Merck, Mirum, and Grail face key regulatory milestones with the FDA throughout the final week of September.

Updated on Sept. 21, 2026 in Healthcare

Isometric editorial illustration of three sleek, cylindrical metallic vials arranged on a flat surface, representing pharmaceutical regulatory assessment processes. — The FDA will conduct critical regulatory assessments for Merck, Mirum, and Grail between September 21 and 26, marking key milestones for their product pipelines. AI Illustration. Upload story photo >

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The Food and Drug Administration has scheduled critical regulatory assessments for Merck, Mirum, and Grail between September 21 and September 26. These updates include PDUFA dates for new drug applications and an advisory committee review for a novel cancer blood test.

Why it matters

These regulatory milestones represent significant inflection points for each company's product pipeline and long-term commercial strategy. Investors and the broader healthcare sector are closely watching these outcomes to assess potential market expansion and new diagnostic approvals.

Merck reported $588 million in second-quarter sales for Winrevair, while Mirum and Grail held $561.3 million and $767.6 million in cash, respectively, as of the end of June.

The players

Merck

Merck is a global pharmaceutical company focused on the development of prescription medicines and vaccines.

Mirum

Mirum is a biopharmaceutical company specializing in the treatment of rare diseases.

Grail

Grail is a healthcare company that develops multi-cancer early detection blood tests.

Incyte

Incyte is a biopharmaceutical company that discovers and develops therapeutics for oncology and inflammation.

FDA

The Food and Drug Administration is the federal agency responsible for regulating food and drug safety in the United States.

The details

Merck seeks an expanded application for Winrevair, while Mirum awaits a decision on Zilurgisertib, a treatment for FOP that involves an upfront acquisition cost of $16 million. Additionally, Grail will present its Galleri cancer test, which currently operates as a laboratory-developed test, to an advisory committee for potential approval.

September 21, 2026: PDUFA date for Merck's Winrevair application.
September 23, 2026: FDA advisory committee reviews Grail's Galleri test.
September 26, 2026: PDUFA date for Mirum's Zilurgisertib application.

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Allergies
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Cancer
Sept. 21
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Market Landscape

These regulatory milestones underscore the high-stakes nature of the pharmaceutical industry, where commercial viability depends on timely agency approvals. As these companies navigate the FDA process, the industry continues to see significant consolidation and investment in rare disease and diagnostic technologies.

Patients and healthcare providers should monitor these decisions as they could lead to the approval of new treatment options or diagnostic tools. Investors should note that company stock valuations may fluctuate based on the official FDA rulings announced this week.

The takeaway

Regulatory deadlines represent pivotal moments for pharmaceutical companies and their shareholders. These outcomes ultimately dictate which new medical innovations reach the market and become accessible to the public.