Roche looks to Astex in $515m breast cancer deal

Roche's Genentech unit has forged an alliance with Astex, worth up to $515 million, to partner on a fragment-based drug discovery programme in breast cancer.

The UK-based biotech, a subsidiary of Japanese group Otsuka, is getting an upfront fee of $25 million in return for exclusive rights to a programme that has emerged from an earlier collaboration between Astex, Newcastle University, and Cancer Research UK's innovation unit Cancer Research Horizons.

There is another $490 million in potential milestone payments if the small-molecule drug candidates – which are described as having selective inhibitory activity against an unidentified target in breast cancer – reach the market and perform as hoped.

Astex's Pyramid drug discovery platform uses small fragments to identify hotspots on protein targets, which are then elaborated into larger drug-like molecules, and has already generated a number of approved drug therapies, including Novartis' CDK4/6 inhibitor Kisqali (ribociclib) for breast cancer, a $4.8 billion-a-year blockbuster.

Others include AstraZeneca's AKT inhibitor Truqap (capivasertib) for breast cancer, which grew 68% to $728 million last year, and Johnson & Johnson's FGFR inhibitor Balversa (erdafitinib) for bladder cancer, which had been tipped as a potential blockbuster but has underwhelmed so far due to a combination of strict biomarker testing barriers, challenging side effects, and fierce competition from newer drug combinations.

Astex is providing existing candidates from its pipeline and will also work with Genentech on optimisation and development of lead candidates for preclinical development.

"Working together with colleagues from Newcastle University, Astex's fragment-based drug discovery expertise has led to the discovery of a novel and innovative approach to selectively inhibit this key oncology target for breast cancer therapy," said the UK-based company's president, Michelle Jones.

"Genentech's focus on embracing innovation, its expertise in oncology and its longstanding dedication to innovation for breast cancer patients makes [it] an excellent partner for this collaboration."

Astex is also partnering with MSD and Taiho on KRAS inhibitors for cancer, headed by oral KRAS G12C inhibitor calderasib (MK-1084), which started a phase 3 programme in 2024 in non-small cell lung cancer (NSCLC) and colorectal cancer.

The company's in-house pipeline is headed by beroterkib. An ERK 1/2 inhibitor, partnered with Mosaic Therapeutics, which is being developed in mid-stage trials for solid tumours.