Former FDA Commissioner Makary's Rejections Became a Biotech Industry Flashpoint

Introduction

The U.S. Food and Drug Administration's repeated rejection of Replimune's melanoma therapy became one of the most closely watched regulatory controversies in the biotechnology industry in 2026. The case centered on RP1, later approved as Tudriqev, an engineered viral immunotherapy developed for patients with advanced melanoma.

The controversy intensified because the therapy was rejected twice during the tenure of former FDA Commissioner Marty Makary, before ultimately receiving accelerated approval after a third submission under new FDA leadership. The reversal turned the case into a broader debate about regulatory consistency, clinical-trial standards, and how the FDA evaluates innovative cancer therapies.

Why Replimune's Drug Became a Regulatory Flashpoint

Replimune initially submitted its application for RP1 in November 2024. The FDA rejected the application in July 2025 and rejected a second submission in April 2026.

At the center of the FDA's concerns was the design of the clinical study. RP1 had been evaluated in a single-arm trial, meaning there was no separate control group receiving a comparator treatment. In addition, patients received RP1 in combination with Opdivo (nivolumab), making it difficult for regulators to determine how much of the observed treatment effect was attributable specifically to RP1.

The FDA argued that additional evidence from a well-controlled trial was necessary to establish the drug's effectiveness.

Makary Defended the FDA's Decision

Former Commissioner Marty Makary publicly defended the agency's rejection as criticism from investors, biotechnology executives, physicians, and other industry observers grew.

In May 2026, Makary said the FDA had followed the scientific and regulatory process and pointed to the agency's complete response letter for the reasoning behind the decision.

The controversy became particularly intense because some cancer specialists and industry representatives argued that the available clinical evidence showed meaningful benefit for patients with advanced melanoma who had already stopped responding to anti-PD-1 therapies.

Critics questioned whether requiring a traditional controlled trial was appropriate for a patient population with limited treatment options, while FDA officials maintained that reliable evidence of effectiveness was necessary for approval.

The Debate Over the Clinical Trial

The lack of a control arm became the central scientific issue.

Replimune's study reported tumor responses among patients who had previously received immunotherapy. Supporters of the treatment argued that these responses were clinically meaningful and that using Opdivo alone as a control could be difficult to justify because the patients had already progressed on anti-PD-1 treatment.

Regulators, however, faced a different question: How confidently could the observed benefit be attributed to RP1 rather than the combination treatment or other factors?

This disagreement illustrated a broader challenge facing regulators as innovative therapies are developed for increasingly difficult-to-treat diseases.

Industry Concerns About Regulatory Consistency

The Replimune case became larger than a dispute over one cancer drug. It became a symbol for concerns within parts of the biotechnology industry about whether FDA decisions were becoming less predictable.

Industry observers pointed to disagreements between Replimune and the agency over previous regulatory discussions and trial requirements. The repeated rejection of RP1 raised questions about how companies should respond when regulatory expectations appear to change during the development process.

The issue was especially significant for smaller biotechnology companies, which can have limited financial resources and may struggle to survive prolonged regulatory delays or repeated requests for additional clinical evidence.

Leadership Change Opens the Door to a Third Attempt

The regulatory situation changed following leadership changes at the FDA.

After Makary's departure, Replimune reached an agreement with the agency on a path to submit the application for a third review. The company resubmitted its application, and the FDA agreed to an expedited review.

The new review became an important test of whether the FDA would take a different view of the existing clinical evidence.

In July 2026, an FDA advisory committee voted 10–3 that the available data were sufficient to be considered clinically meaningful. Although advisory committee recommendations are not binding on the FDA, the vote represented a significant change in the regulatory trajectory of RP1.

From Controversy to Approval

The FDA ultimately granted accelerated approval to Tudriqev, bringing the regulatory saga to an end after three submissions and two previous rejections.

The approval allows the treatment to be used in combination with Opdivo for eligible patients with advanced melanoma whose disease has progressed following prior anti-PD-1 therapy.

The decision represents a major turnaround for Replimune and provides the company with its first approved therapy. It also demonstrates how regulatory outcomes can evolve as new evidence, agency leadership, and expert assessments change.

What the Case Means for Biotech

The Replimune episode highlights several important issues for the biotechnology industry.

First, clinical-trial design remains critical. Innovative therapies may show promising results, but regulators still need sufficient evidence to distinguish treatment effects from other variables.

Second, regulatory predictability matters. Biotechnology companies invest years and substantial capital developing therapies, making clear and consistent communication with regulators particularly important.

Finally, the case demonstrates the potential role of the accelerated approval pathway in diseases where patients have serious unmet medical needs. Accelerated approval can allow promising treatments to reach patients while additional studies are conducted to confirm clinical benefit.

The Regulatory Debate Is Not Over

Tudriqev's approval does not completely end the scientific debate surrounding the therapy. Because it received accelerated approval, Replimune must conduct additional studies to confirm its safety and effectiveness.

The results of those confirmatory studies will ultimately help determine the treatment's long-term regulatory position.

This requirement also illustrates the balance the FDA must maintain: giving patients access to promising therapies while ensuring that initial evidence is followed by stronger data confirming clinical benefit.

Conclusion

The controversy surrounding Marty Makary's FDA tenure and Replimune's melanoma therapy became a major flashpoint for the biotechnology industry. Two rejections raised questions about clinical-trial standards, regulatory consistency, and the treatment of innovative therapies for patients with limited options.

The subsequent third review and accelerated approval of Tudriqev demonstrated that regulatory decisions can change as agency leadership, expert assessments, and the interpretation of clinical evidence evolve.

For the biotech industry, the Replimune case serves as a reminder that scientific evidence, regulatory communication, trial design, and agency consistency can all play decisive roles in determining whether an innovative therapy reaches patients.