Novartis bid to block generic Entresto in US suffers setback

A federal appeals court in the US has declined to overturn an attempt by Novartis to block the launch of a generic version of its blockbuster heart failure drug Entresto.

The US Court of Appeals for the Federal Circuit sided with a lower court that blocked the Swiss pharma group's request for an injunction on the launch of the generic, developed by MSN Pharma.

MSN Pharma was given FDA approval for its Entresto (sacubitril and valsartan) generic on 24th July, prompting a legal complaint from Novartis seeking to block its launch. In August, a Delaware court denied its request for a preliminary injunction, but introduced a temporary three-day stay to allow time for the big pharma to lodge its appeal.

The case revolves around Novartis' contention that MSN's generic contains small amounts of crystalline forms of the active ingredients in Entresto that would infringe a patent on the drug (No. 11,096,918) that confers protection until 8th November 2026.

The appeals court ruled, however, that Novartis had failed to provide enough evidence to suggest that it was very likely to win the patent infringement suit on those grounds, saying it saw "no clear error in the district court's analysis."

Novartis said it disagrees with the verdict and is "considering all available options to vigorously defend our intellectual property rights, including further appellate options." The patent infringement lawsuit is scheduled to start next week.

A lot is riding on the case for Novartis, as Entresto is its top-selling product, contributing more than $5.6 billion in the first nine months of the year – 19% of its total revenues for the period – with a rise of nearly a third on the same period of 2023. It's still a major growth driver for the company, even though it is nearly a decade since it was first launched in the US.

It is one of three major Novartis products that are nearing the end of their patent lives, along with cancer drug Tasigna (nilotinib) and Promacta (eltrombopag) for thrombocytopaenia, which brought in $1.3 billion and $1.6 billion, respectively, in the first three quarters of 2024.

In its third-quarter results update, Novartis said it was modelling the entry into the US market of Entresto, Promacta, and Tasigna in the middle of 2025, but noted that the timing could change depending on the outcome of litigation.

Entresto has been approved by the FDA since 2015 to reduce the risk of cardiovascular death and hospitalisation for heart failure in adult patients with chronic heart failure, with its label extended to include paediatric patients and patients with higher left ventricular ejection fraction (LVEF) measures.

The Delaware district court also struck down a so-called 'combination patent' (No. 8,101,659) on Entresto last year in a case that has also gone to appeal. Meanwhile, Novartis has also sued the FDA, claiming that its approval of the generic was unlawful, after the regulator rejected a Citizen's Position submitted by the company asking it to reconsider.

Image by Sergei Tokmakov from Pixabay