Astellas adds to claudin clout with $1.3bn+ Evopoint deal

Astellas was the first company to bring a drug against the claudin target CLDN18.2 to market, and has now added another to its cancer pipeline via a partnership with China's Evopoint Biosciences.

The new deal includes an upfront payment of $130 million for exclusive worldwide rights outside China, Hong Kong, Macao, and Taiwan to XNW27011, a CLDN18.2-directed antibody-drug conjugate (ADC) currently in phase 1/2 testing.

There's another $1.34 billion on offer if the ADC hits development, regulatory and commercial objectives, according to Astellas, which said XNW27011 is "a promising new asset that complements Astellas' pipeline and enhances our leading position in precision oncology." Around $70 million of "near-term," payments are included in that total.

The ADC uses a proprietary topoisomerase I inhibitor payload and linker technology, "an approach that has demonstrated clinical success in other approved cancer therapies," according to the Japanese group.

Astellas claimed approval last year for antibody-based Vyloy (zolbetuximab) as the first-in-class anti-CLDN18.2 drug, at its second attempt, getting a green light for the drug as a first-line therapy for locally advanced or metastatic HER2-negative, CLDN18.2-positive gastric or gastroesophageal junction adenocarcinomas that cannot be treated with surgery.

Sales of Vyloy came in at JPY 12.2 billion ($85 million) last year, after just a few months on the market and according, to some analysts, are tipped to reach $1 billion or more, although achieving those levels will depend on widespread adoption of CLDN18.2 testing, which isn't routinely carried out at the moment.

Vyloy said in its financial update for 2024 that sales of the drug had "expanded beyond expectation," which it put down to "faster-than-expected market penetration of claudin 18.2 testing." It is predicting sales will reach JPY 40 billion ($278 million) this year.

CLDN18.2 is a transmembrane protein expressed in approximately 38% of advanced gastric cancer cases, and is also expressed in some other solid tumours, including pancreatic cancer. It is not generally encountered in healthy tissues, making it almost completely tumour-specific, which should avoid off-target effects.

The deal with Evopoint boosts Astellas' claudin pipeline as other CLDN18.2 candidates come through the industry pipeline from the likes of Innovent Bio, AstraZeneca/Keymed, and others.

It also fulfils the company's strategic objective of building its presence in ADCs, which have emerged in recent years as a major force in cancer treatment.