Replimune Group, the Woburn-based biotech behind the oncolytic immunotherapy RP1, is cutting roughly 63 jobs at its local facility after the U.S. Food and Drug Administration rejected its Biologics License Application. The company says the decision makes continued development and U.S. manufacturing of RP1 “not viable” without an accelerated-approval pathway. Employees learned the news this week through a WARN filing, and Replimune says it will substantially scale back domestic manufacturing operations.
What the FDA said
The FDA’s review team wrote that a reanalysis of the resubmission found the available data “insufficient to conclude substantial evidence of effectiveness,” citing difficulty isolating RP1’s contribution when used with nivolumab, heterogeneity in study populations and response-assessment issues. Regulators detailed concerns about the single-arm RPL-001-16 study and an early analysis from RP1-104 and said those data cannot support approval as submitted, according to the agency’s complete response letter from the FDA.
Replimune's response and next steps
Replimune pushed back, arguing the agency’s conclusions contradict prior discussions and the company’s read of the IGNYTE data. "As we previously communicated, without timely accelerated approval, the development of RP1 will not be viable," CEO Sushil Patel said in the company’s statement reported by StreetInsider. The company noted it had already launched a global Phase 3 IGNYTE-3 confirmatory trial but said the resubmission still failed to satisfy FDA reviewers.
Local impact: WARN filing and jobs
A state WARN notice filed this week shows Replimune notified officials it plans to eliminate 63 roles at its Woburn site, with layoffs scheduled to take effect between April 13 and April 24, as reported by local outlets. The filings and company statements indicate the reductions are concentrated in U.S. manufacturing and operations, landing a direct hit on Woburn’s life-sciences workforce.
Market reaction and industry fallout
Investors punished the company after the complete response letter, with coverage noting a steep share decline and swift analyst downgrades that highlighted how binary late-stage biotech outcomes can be for both jobs and investors. The regulatory setback and Replimune’s warning about cutting U.S. manufacturing were widely cited in national business coverage.
What this means for patients and the plant
The FDA letter underscores that regulators are looking for adequate, well-controlled evidence, a standard that will likely require larger randomized data or a robust confirmatory study before approval is granted. That expectation stretches timelines for patient access and, according to Replimune, undercuts the economics of continuing domestic manufacturing without regulatory flexibility. The company says it will update employees and stakeholders as it evaluates its next steps.
For Woburn, the cuts serve as a stark reminder that late-stage regulatory swings can have immediate local consequences. Replimune said it will provide additional information to affected employees and will continue to engage with regulators as it considers its path forward.
