Gilead follows Roche in hitting immune system suppression

Yesterday’s deal between Gilead and Jounce shows biopharma’s continued interest in T regulatory cells, or Tregs, a relatively poorly understood cell type. It is also, of course, yet another oncology tie-up for Gilead, following deals with Forty Seven, Arcus, Pionyr and Tizona. The latest collaboration focuses on Jounce’s JTX-1811, a preclinical antibody against CCR8, a receptor expressed on intratumoural Tregs. The idea is that targeting CCR8 can deplete specific Tregs – these damp down immune response – eliminating one mechanism cancer uses to evade the immune system. Two years ago Roche paid $81m to buy Tusk Therapeutics, another preclinical player looking at Treg depletion, in its case by hitting CD25 and CD38. A parallel approach to tipping the balance in favour of anti-tumour immunity is to deplete immunosuppressive myeloid cells, and here Gilead already has a presence through the Pionyr deal. Interestingly JTX-1811 did not appear in Jounce’s pipeline when the company was floating in 2017, and no other industry assets appear to be targeting CCR8. The $120m from Gilead could add further confidence after Celgene last year opted out of Jounce’s lead asset, the anti-Icos MAb vopratelimab.