As Blenrep returns, GSK adds another ADC to cancer pipeline

GSK has boosted its pipeline of antibody-drug conjugates for cancer, licensing a prostate cancer candidate from Syndivia in a deal that could be worth up to £268 million ($358 million).

The object of GSK's attention is a preclinical-stage candidate, which has not been identified by the two partners, but which has potential as a "best-in-class" treatment for advanced castration-resistant prostate cancer (CRPC).

The UK pharma group – which is in the process of resuming sales of its multiple myeloma ADC Blenrep (belantamab mafodotin) after it was withdrawn from sale a few years ago – said that the new candidate would complement a "diverse pipeline" in prostate cancer.

That also includes a B7H3-targeted ADC (GSK5764227), licensed from China's Hansoh in a $1.7 billion deal in 2023, which generated encouraging data in osteosarcoma at the recent ESMO cancer congress.

For Strasbourg, France-based Syndivia, the deal is its first external partnership for an ADC derived from its proprietary GeminiMab conjugation technology, which aims to create ADCs that are highly specific to their targets, deliver potent cell-killing payloads, and have a low tendency for earlier, off-target release that could lead to side effects.

It already has an alliance in place with Auricula Biosciences, a company that it set up with TVM Capital Life Science in 2022 to advance a pan-KRAS-targeted albumin-drug conjugate through clinical development. That candidate – codenamed WEF-001/SDV-1001 – is in a phase 1/2 trial in KRAS-mutant solid tumours.

In a statement, GSK said Syndivia's drug "could provide a targeted treatment directly to the tumour, currently a gap in available therapies, along with a more easily accessible treatment in the community practice setting for mCRPC."

The deal includes an undisclosed upfront payment, development and commercial milestone payments, and tiered royalties on sales if the ADC reaches the market. GSK has global development, manufacturing, and commercialisation rights to the drug.

mCRPC is seen in up to 20% of the approximately 1.4 million men diagnosed with prostate cancer each year around the world, and has a low five-year survival rate of around 30% and a median survival in the region of two years.

The deal is the first announced by GSK since it announced the unexpected departure last month of chief executive Emma Walmsley, who will step down next month and be replaced by current chief commercial officer Luke Miels.