Replimune shares tumble after FDA flags skin cancer trial data, law firm launches probe

Kirby McInerney said it is investigating Replimune after FDA reviewers called the company’s RP1 study "non interpretable," a setback that drove the stock down 38% on July 28, 2026.

Summary

Replimune Group came under added investor scrutiny after FDA briefing documents on July 28, 2026 said the single-arm mid-stage study submitted to support approval of vusolimogene oderparepvec, or RP1, for skin cancer was "non interpretable." FDA reviewers said the assessment used in the study "confounds interpretation of the reported efficacy results and limits FDA’s ability to verify the reported results." Replimune’s stock fell $3.28, or about 38%, to close at $5.35 on July 28, 2026. Kirby McInerney LLP said it is investigating possible federal securities law violations tied to the company. An earlier investor-law-firm announcement had identified a similar probe by the Law Offices of Frank R. Cruz.

Terms & Concepts
  • single-arm mid-stage study: A clinical trial in which all participants receive the experimental treatment, typically used to assess activity and safety before late-stage testing.
  • briefing documents: Materials released ahead of a regulatory review that summarize the agency’s and the company’s positions on a drug application.
  • federal securities law violations: Potential breaches of U.S. rules governing disclosures, trading, and investor protections in public markets.