MHRA clears third JAK inhibitor for severe alopecia areata, but NHS funding fight looms

The UK's Medicines and Healthcare products Regulatory Agency has approved deuruxolitinib, sold as Leqselvi, for adults with severe alopecia areata, giving Sun Pharma UK a licence for an oral JAK1/JAK2 inhibitor taken twice daily at 8mg. The agency based its decision on the THRIVE-AA1 and THRIVE-AA2 trials, which enrolled roughly 1,223 patients and found about 30% reached at least 80% scalp coverage after 24 weeks, with 23% reaching 90% coverage. The MHRA says it will keep the drug's safety and effectiveness "under close review," language that matters more than it might appear given what has happened to this drug's two closest competitors.

Leqselvi becomes the third JAK inhibitor licensed in the UK for severe alopecia areata, joining Pfizer's ritlecitinib (Litfulo) and Eli Lilly's baricitinib (Olumiant). Having an MHRA licence is not the same as having NHS funding, and the record for this drug class on that second hurdle is uneven. The National Institute for Health and Care Excellence initially issued a negative draft recommendation for ritlecitinib before reversing course after Pfizer offered a larger confidential discount, a reversal formalized in NICE's Technology Appraisal 958. Baricitinib fared worse: NICE declined to recommend it for NHS funding in this indication, and an appeal brought by the charity Alopecia UK was dismissed. Patients seeking baricitinib on the NHS now have to go through an Individual Funding Request and demonstrate what the appraisal process calls "clinical exceptionality," a high bar that has left many without access despite the drug carrying an MHRA licence of its own.

Sun Pharma has not yet disclosed what price it will propose for Leqselvi in the UK, and that number, measured against ritlecitinib's discounted NICE-accepted price, will likely decide whether the drug follows ritlecitinib's path to NHS funding or baricitinib's path to rejection. NICE's appraisal of deuruxolitinib is expected around October 2026, according to the research timeline cited by Alopecia UK, which has pushed for a positive recommendation and will be a stakeholder in that process. Until NICE rules, MHRA approval gives patients and clinicians a prescribing option but not a funding guarantee.

The MHRA release does not mention that Leqselvi has already been through a rockier regulatory path in the United States, where the FDA approved it in July 2024, nearly two years before this UK decision. That approval did not translate into an immediate launch. Incyte Corporation sued Sun Pharma for patent infringement over US Patent 9,662,335, tied to Incyte's own JAK inhibitor franchise, and won a preliminary injunction in a New Jersey federal court around November 1, 2024, blocking Sun from commercializing the drug just as it was preparing to launch, as reported by Fierce Pharma. Sun Pharma appealed, the injunction was lifted, and the companies reached a settlement under which Sun agreed to pay Incyte an upfront fee plus ongoing royalties until the disputed patent expires in December 2026, according to Fierce Pharma's follow-up reporting. Leqselvi subsequently launched in the US market. Incyte's own SEC filings will carry the most current account of whether that settlement fully resolved the litigation.

That royalty arrangement runs through the end of next year and applies to a drug now entering a separate pricing negotiation in the UK, where Sun Pharma will have to weigh US litigation costs against whatever discount it needs to clear NICE's cost-effectiveness threshold. The company has not said whether the Incyte settlement terms will factor into its UK pricing strategy.

Leqselvi's US label carries a boxed warning covering four risks: serious infections including tuberculosis reactivation, malignancy, major adverse cardiovascular events such as death, heart attack and stroke, and thrombosis including cerebral venous sinus thrombosis, deep vein thrombosis and pulmonary embolism, according to the FDA label filed with the agency. That warning was extrapolated from trial data on a different JAK inhibitor, tofacitinib, studied in rheumatoid arthritis patients rather than in deuruxolitinib's own alopecia trials, a practice that has applied across the JAK inhibitor class since the FDA's 2021 ORAL Surveillance findings on tofacitinib. It is a boxed warning inherited rather than generated by Leqselvi's own clinical program, and it sits behind the MHRA's promise to keep watching the drug once it reaches UK patients.