Incyte blocks US launch of Sun Pharma's alopecia drug

A US district court has granted an injunction sought by Incyte on the launch of Sun Pharma's recently approved Leqselvi for alopecia areata.

In a brief filing with the National Stock Exchange (NSE) of India, the company confirmed that on 1st November the New Jersey court decided to grant a preliminary injunction that will delay the launch of Leqselvi (deuruxolitinib), which was approved by the FDA in July.

"As a result of the court decision, Sun is stopped from launching Leqselvi until a subsequent favourable court decision or until the expiry of patent in lawsuit, whichever is earlier," said the company, adding: "We respectfully disagree with and intend to immediately appeal this decision."

Leqselvi is a rival to Incyte and parent Eli Lilly's Olumiant (baricitinib), which in 2022 became the first approved systemic therapy for alopecia areata, an autoimmune condition causing patchy hair loss that affects more than 700,000 people in the US. Both drugs are JAK 1/2 inhibitors and have been cleared for use in adults with severe hair loss caused by the condition.

Incyte filed a lawsuit to try to block the launch of Leqselvi, claiming that the drug infringed a US patent (No. 9,662,335) it holds on the use of ruxolitinib, a JAK inhibitor it sells as Jakafi to treat various haematological cancers and in a topical form as Opzelura for atopic dermatitis and vitiligo.

Deuruxolitinib is a deuterated form of ruxolitinib, which Incyte claims in the lawsuit has been "a cornerstone" of the company's "scientific and business efforts" for more than two decades. It makes the case that the '335 patent covers claims on deuterated forms of the compound – a modification used to improve pharmacokinetic properties – that are infringed by Sun Pharma's compound.

Ruxolitinib itself has shown efficacy in alopecia studies, but has side effects at the doses needed to have an effect.

Shares in Sun Pharma fell sharply after the NSE filing as investors reacted to the news. The drugmaker has previously said that it hopes to achieve $200 million in annual sales from the drug within the next three to four years, and was in the midst of pre-launch activities when Incyte's lawsuit was filed.

The Indian drugmaker acquired the programme when it took over US-based Concert Pharma last year, in a deal valued at $576 million, and has said Leqselvi offers "best-in-class" properties.

Other rivals include Pfizer, whose JAK3/TEC inhibitor Litfulo (ritlecitinib) was approved by the FDA for alopecia areata in June 2023, shortly after Olumiant's green light for the indication.

Photo by Andreas Haubold on Unsplash