The US Food and Drug Administration (FDA) is reviewing a petition seeking to revoke the approval of Ocrevus, a blockbuster drug developed by Roche, for the treatment of Primary Progressive Multiple Sclerosis (PPMS).

The review follows concerns raised in an investigation published by The BMJ, which examined the circumstances surrounding the drug’s 2017 approval. The petition alleges that internal FDA reviewers had flagged limited effectiveness in certain patient groups, particularly women, as well as a potential increased risk of breast cancer.

Primary progressive multiple sclerosis, which affects around 15 percent of MS patients, is a chronic and debilitating neurological condition with limited treatment options. However, the petition argues that evidence supporting Ocrevus’ benefit in this group may have been overstated, particularly for women and patients without active disease.

According to the report, several FDA scientists expressed reservations during the review process, citing ‘near zero efficacy’ in some patients, concerns over data integrity at clinical trial sites and safety signals related to breast cancer incidence. Despite these concerns, the drug was approved for use in both men and women, with regulators opting to include cancer risk information in product labelling and mandate further post-approval studies.

Experts have since raised questions about the long-term benefit-risk profile of the therapy, noting that key safety studies on cancer risk are not expected to be completed until 2030. Some have called for a more restricted use of the drug, limiting treatment to patients who demonstrate clear short-term benefits.

Roche has defended the safety and efficacy of Ocrevus, stating that ongoing monitoring has not identified any new safety concerns. The company also cited additional data supporting the drug’s benefit, though interim findings related to cancer risk have not been publicly disclosed.

The case has renewed scrutiny of regulatory pathways designed to fast-track treatments addressing unmet medical needs, raising broader questions about approval standards and post-market oversight in the pharmaceutical industry.