FRANKFURT, Germany: Novartis has agreed to acquire an experimental breast cancer drug from U.S.-based Synnovation Therapeutics in a deal worth up to US$3 billion, strengthening its pipeline of targeted cancer treatments.

The Swiss drugmaker will pay $2 billion upfront, with an additional $1 billion tied to development milestones, the companies said.

The drug candidate, SNV4818, is a selective PI3Kα inhibitor designed to treat HR-positive/HER2-negative breast cancer, as well as potentially other solid tumours. It represents a newer approach aimed at targeting specific cancer-driving mutations.

SNV4818 is currently in early-stage trials and has shown promising activity against tumours in laboratory studies, Novartis said.

The therapy is designed to target only the mutated form of the PI3Kα enzyme, which is commonly implicated in breast and other cancers, while avoiding the normal version present in healthy cells. The goal is to reduce side effects associated with existing PI3Kα-targeting treatments.

"While mutated PI3Kα is a well-established driver in HR+/HER2 breast cancer, there remains a challenge in achieving effective pathway inhibition with a tolerable therapeutic profile," said Shreeram Aradhye, Novartis' chief medical officer.

The acquisition adds to Novartis' growing portfolio of precision oncology treatments, including its work on radioligand therapies and other targeted approaches.

The company has been focusing on expanding its cancer drug pipeline with therapies that aim to improve effectiveness while minimising adverse effects, particularly in difficult-to-treat cancers.

The deal is expected to close in the first half of the year, subject to customary conditions.

With the addition of SNV4818, Novartis is looking to strengthen its position in oncology by advancing treatments that address unmet medical needs and improve outcomes for patients with specific cancer types.