Gilead and GSK nab early ADCs

Despite recent setbacks, antibody-drug conjugates remain hot, as shown by two big pharma deals just this week. Although the agreements are small and early, further details on the projects in question will be eagerly awaited.

Gilead announced a collaboration on Tuesday, worth $20m up front, with Tubulis over an ADC against an unnamed solid tumour target. And on Wednesday GSK licensed DualityBio’s DB-1324 worldwide (excluding China) for $30m up front; the target of that project is also undisclosed.

DualityBio mystery

Both projects are preclinical, although Duality’s might be slightly further ahead. All the companies are saying is that the asset, which uses Duality’s topoisomerase inhibitor-based DITAC platform, hits a gastrointestinal target.

Duality has an extensive pipeline of ADCs, so it’s possible to deduce what DB-1324 is not. The Chinese group is developing three projects alongside BioNTech, targeting HER2, TROP2 and B7-H3. It also has a deal with BeiGene over a B7-H4-targeting project, and unpartnered assets against HER3 and DLL3.

DB-1324 might therefore hit something like Claudin18.2, a hot GI target that GSK isn’t currently involved in.

GSK’s existing ADC efforts comprise the BCMA-targeting Blenrep, and B7-H3 and B7-H4 projects licensed from Hansoh for $270m in aggregate.

Tubulis tie-up

Gilead, meanwhile, already has an approved TROP2 ADC, Trodelvy, gained via its much maligned $21bn purchase of Immunomedics.

This week’s much smaller deal with privately held Tubulis will give the big biotech access to its partner's so-called Alco5 and Tubutecan technology; the latter is a topoisomerase inhibitor linker-payload platform.

Tubulis reckons it could address current ADC limitations such as lack of durability and off-target toxicity. Still, the group has much to prove: its lead assets, the 5T4-targeting TUB-030 and Napi2b-targeting TUB-040, are in early-stage trials, with no clinical data yet.

In 2023 Bristol Myers Squibb also signed a licensing deal with Tubulis worth nearly $23m up front.

At least if Gilead's Tubulis tie-up comes to nothing it won’t get accused of overpaying this time.