Sun Pharma overturns block on alopecia drug launch in US

Sun Pharma successfully removed an injunction in the US on the launch of its Leqselvi for alopecia areata, a common form of hair loss, that was sought by rival Incyte.

The decision in the US Court of Appeals for the Federal Circuit followed oral arguments in which Incyte had argued that its patents on its rival therapy would be infringed by the launch of Leqselvi (deuruxolitinib) – even though it is still some way off bringing its drug to market.

The court was unimpressed by its position that the temporary injunction awarded last November should be maintained over the long term and vacated the block – effective immediately.

In a brief filing with the National Stock Exchange (NSE) of India, Sun Pharma said that patent litigation with Incyte is still ongoing and – for now at least – it is not ready to disclose its launch plans for Leqselvi in the US. Making the drug available could risk financial consequences down the line if Incyte ends up winning the lawsuit.

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. Another competitor is Pfizer's JAK3/TEC inhibitor Litfulo (ritlecitinib), which was approved by the FDA in 2023.

Incyte's infringement lawsuit is claiming that Sun Pharma's drug infringes a US patent (No. 9,662,335) it holds on the use of a ruxolitinib – a JAK inhibitor it sells as Jakafi to treat various haematological cancers as well, in a topical form as Opzelura for atopic dermatitis and vitiligo – which extends to include deuterated forms of the drug.

Jakafi is its top-selling product, with sales of $2.8 billion last year, while Opzelura added another $508 million.

Leqselvi is also based on 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.

In February, Incyte updated the court on its development plans for ruxolitinib and deuruxolitinib, saying it had added a phase 1 trial of a foam formulation and intended to start phase 2/3 trials, although the timeline for those – and its expected filing date – have been redacted.

Sun Pharma acquired Leqselvi when it took over US-based Concert Pharma in 2023 in a deal valued at $576 million and has said Leqselvi offers "best-in-class" properties.

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