Moderna falls after FDA refuses to review flu vaccine application
Regulatory setback for mRNA-1010 seasonal influenza shot comes as biotech company faces declining revenue and pipeline diversification challenges
Moderna shares declined on Tuesday after the US Food and Drug Administration declined to review the company's seasonal influenza vaccine application, marking another regulatory hurdle for the biotechnology company as it seeks to diversify beyond its COVID-19 franchise.
The FDA's Center for Biologics Evaluation and Research issued a Refusal-to-File letter for Moderna's mRNA-1010 Biologics License Application, citing that the clinical trial's comparator arm "does not reflect the best-available standard of care." The decision means the agency will not proceed with a formal review of the application without additional action from the company.
The regulatory setback represents a significant delay for Moderna's efforts to establish a respiratory vaccine portfolio that includes influenza, respiratory syncytial virus (RSV), and combination shots. mRNA-1010 is one of the company's most advanced non-COVID vaccine candidates, positioning it as a critical component of Moderna's strategy to generate revenue beyond its pandemic-era vaccine sales.
Moderna pushed back against the FDA's reasoning, stating in a regulatory filing that the decision is inconsistent with previous written communications from CBER indicating that using a licensed standard-dose influenza vaccine as a comparator would be acceptable. The company emphasized that the FDA's letter did not identify any safety or efficacy concerns with mRNA-1010 itself, leaving the regulatory pathway potentially salvageable.
"We believe this decision is inconsistent with prior written feedback from CBER, which indicated that a licensed standard-dose influenza vaccine as a comparator would be acceptable," Moderna said in a statement reported by CNBC. "We have requested a Type A meeting with CBER to discuss the path forward."
The Cambridge, Massachusetts-based company said it does not expect the FDA action to impact its 2026 financial guidance. Meanwhile, mRNA-1010 applications remain under review in the European Union, Canada, and Australia, where Moderna anticipates potential approvals beginning in late 2026 or early 2027.
The regulatory headwinds come as Moderna faces mounting pressure to demonstrate a sustainable business model following the windfall of its COVID-19 vaccine. The company's revenue has declined 45.4% year-over-year, with analysts projecting a 41% sales decline for the current year as pandemic demand fades. Quarterly earnings have dropped 85.1% compared with the prior year, reflecting the challenges of scaling from a single-product pandemic success to a diversified biotechnology platform.
Moderna's stock, which closed at $41.99 on Tuesday, has fallen significantly from its pandemic-era highs but remains above some analysts' price targets. The company's analyst consensus target of $38.80 suggests additional downside potential, with ratings showing mixed sentiment—22 analysts rate the stock a hold, while three recommend buying and three suggest selling.
The FDA's refusal-to-file action follows previous regulatory challenges for Moderna's expansion efforts. In December 2025, shares declined following FDA commentary on approval standards for mRNA vaccines, and September 2025 saw similar stock pressure related to regulatory guidance. These setbacks have raised questions about the smooth translation of Moderna's mRNA technology platform from COVID-19 to other disease areas.
Moderna maintains a pipeline spanning cancer, rare diseases, cardiovascular disorders, and autoimmune conditions, with more than 40 programs in development. However, the flu vaccine represents a particularly important near-term opportunity, given the established market for seasonal influenza vaccines that generates billions in annual revenue for established competitors including Sanofi, GlaxoSmithKline, and Seqirus.
Investors will be watching for the outcome of Moderna's requested Type A meeting with FDA officials, which could clarify what additional data or study designs would satisfy regulatory requirements. The company has not provided a timeline for when such a meeting might occur.
The FDA's decision also raises broader questions about regulatory standards for mRNA-based vaccines, as the agency applies scrutiny developed during the COVID-19 pandemic to next-generation applications. The comparator arm issue suggests regulators are increasingly demanding state-of-the-art trial designs even for established vaccine targets, potentially raising the bar for mRNA companies seeking approvals in crowded therapeutic areas.