The European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) issued a negative opinion on July 23, 2026, recommending refusal of the Marketing Authorization Application (MAA) for arimoclomol (Miplyffa) submitted by Zevra Therapeutics (Nasdaq: ZVRA) for the treatment of Niemann-Pick disease type C (NPC) in the EU. The Boston-based company said it plans to request a formal re-examination of the opinion within the 15-day window permitted under European regulatory procedures.
The CHMP's rationale, published in the EMA's assessment report, centered on insufficient demonstration of efficacy. The agency concluded that uncertainties in data handling and analytical approach undermined the reliability of the pivotal trial results. Specifically, the committee found no benefit in ambulation or cognition domains, and while a subgroup of patients also receiving miglustat showed a treatment effect favoring arimoclomol, the CHMP did not consider this finding robust given the absence of a demonstrated effect in the overall study population. The pivotal trial enrolled 50 children and adolescents aged 2 to 18 years.
Arimoclomol received US FDA approval in September 2024 as the first approved treatment for NPC in the United States, indicated in combination with miglustat for neurological manifestations of the disease in patients aged two years and older. In Europe, miglustat (Zavesca) remains the only authorized pharmacological therapy for NPC neurological symptoms. The negative CHMP opinion means European patients currently have no access to arimoclomol outside of expanded access programs; Zevra said it will continue supporting eligible patients through its global Expanded Access Program while the re-examination proceeds.
The NPC treatment landscape is becoming more active. Thousand Oaks, California-based Beren Therapeutics P.B.C. has an NDA for adrabetadex under FDA Priority Review for infantile-onset NPC, with a PDUFA target action date of November 17, 2026. Adrabetadex targets the underlying cholesterol trafficking defect via a distinct cyclodextrin-based mechanism and carries an infantile-onset-specific indication, positioning it as complementary rather than directly competitive with arimoclomol in the near term.