Eisai settles Lenvima patent dispute with Torrent Pharma

Eisai has agreed a deal to settle patent infringement litigation with generic drugmaker Torrent Pharma, preventing it from launching a copycat version of Eisai's MSD-partnered cancer drug Lenvima in the US until 2030.

The deal sets aside litigation being heard in a New Jersey district court, which alleged that Torrent's marketing application for a generic of Lenvima (lenvatinib) infringed on two patents held by Eisai (Nos 10,407,393 and 11,186,547). The financial terms of the settlement have not been disclosed.

Eisai has already reached settlement agreements with two other companies seeking to market Lenvima generics in the US – Sun Pharma and Dr Reddy's Laboratories – which, like Torrent, are prevented from launching until 1st July 2030. That is, of course, unless something happens to overturn Eisai's patent protection.

That was put to the test in a patent dispute with Shilpa Medicare earlier this year, also heard in New Jersey, which resulted in the court upholding the validity of the '547 patent. That expires in February 2036, so the judgment prevents Shilpa from launching its generic before that date..

However, the lawsuit also claimed infringement of the '393 patent, although that was not upheld by the court, and Shilpa has since filed an appeal with the US Court of Appeals for the Federal Circuit.

Lenvima is a big earner for both Eisai and MSD, known as Merck & Co in the US and Canada, which licensed rights to the drug in 2018 in a near-$6 billion deal aimed at developing it as a partner drug to its blockbuster cancer immunotherapy Keytruda (pembrolizumab).

According to Eisai, sales of multikinase inhibitor Lenvima were $1.51 billion in the fiscal year ending 31st March, having rocketed in recent years thanks to FDA approvals alongside Keytruda for first-line therapy of kidney cancer and as a second-line treatment for some forms of endometrial cancer.

The drug is also approved by the FDA for use on its own in thyroid, kidney, and liver cancers and is being developed in various other combinations for kidney cancer and with Keytruda for other cancers, with mixed results.

There was a setback just last month, when the Lenvima/Keytruda regimen was unable to achieve an increase in overall survival (OS) compared to placebo in the LEAP-012 study involving patients with hepatocellular carcinoma (HCC), the most common form of liver cancer.

Other combination studies in lung, oesophageal, colorectal, and skin cancers have also disappointed.