Sun Pharma and Celegene Settle Patent Dispute over Lenalidomide (Revlimid®)

Settling an over three old patent infringement dispute, Indian pharmaceutical major, Sun Pharmaceuticals and its subsidiary, including US subsidiary (“Sun”), has reached a settlement with Celgene Corporation (“Celgene”), a subsidiary of pharmaceutical major Bristol Myers Squibb (BMS), to resolve and settle the patent litigation regarding submission of an Abbreviated New Drug Application (ANDA) for a generic version of Revlimid® (lenalidomide) capsules in the US: Celgene Corp. (Bristol Myers Squibb) v. Sun Pharma Case. Celgene sued Sun Pharma for patent infringement in 2018.

While the settlement terms, including exact dates and amount that can be manufactured/sold, has been kept confidential, what has been disclosed is that Celgene will grant Sun Pharma a license to manufacture and sell (subject to USFDA approval) generic lenalidomide capsules in the US (a) limited quantity sometime after March 2022; (b) unlimited quantity after Jan 2026. On the other hand, all Hatch-Waxman litigation between Sun Pharma and Celgene, regarding the Revlimid patents will be dismissed.

Lenalidomide (brand name Revlimid by Celgene) is a thalidomide derivative used to treat multiple myeloma and anemia in low to intermediate-risk myelodysplastic syndrome. For Celgene/BMS Revlimid has turned out to be a blockbuster drug generating over USD 12 billion in revenue in the last year, making it the third-highest drug by worldwide sales in 2020. It was also surrounded by its share of controversy when a US Congressional investigation found that the drug was launched in 2005 at USD 215 per pill, but the price was increased more than 20 times to reach a high of USD 750 per pill.

The patents involved in the infringement suit and settlement are:

• S. Patents No. 7,977,357 titled Polymorphic forms of 3-(4-amino-1-oxo-1, 3 dihydro-isoindo1-2-yl)-piperidine-2,6-dione
• S. Patents No. 8,193,219 titled Polymorphic forms of 3-(4-amino-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione, and
• S. Patents No. 8,431,598 titled Polymorphic forms of 3-(4-amino-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione

The above patents are anticipated to expire around September 2024. Revlimid’s patent cliff was a big concern for Celgene/ BMS, but the companies got some reprieve when the U.S. Patent and Trademark Office rejected Dr. Reddy’s bid to invalidate three Revlimid patents.

Previously, Celgene made similar settlements over patent litigations of Revlimid with Indian pharmaceutical companies — Cipla Ltd., Natco Pharma Ltd., Zydus Cadila, and Dr. Reddy’s Laboratories Ltd., and the U.S. based company Alvogen. All these companies have licenses from Celgene to sell volume-limited amounts of generic lenalidomide capsules in the U.S. starting from sometime after March 2022, which would rise to unlimited sales after January 2026.