Gilead Sciences, Inc. (Nasdaq: GILD) and Arcus Biosciences, Inc. (NYSE: RCUS) have announced a significant amendment to their collaboration agreement, accompanied by a substantial $320 million equity investment by Gilead in Arcus common stock at $21.00 per share. This strategic investment and collaboration amendment are set to accelerate the growth of their joint development programs in multiple cancer indications.

Johanna Mercier, Chief Commercial Officer at Gilead Sciences, will enhance this partnership by joining the Arcus Board, bringing Gilead’s total director designees to three. The amendment includes governance enhancements for more efficient decision-making, reflecting the expanding collaboration scope.

Merdad Parsey, Chief Medical Officer at Gilead Sciences, emphasized the importance of this amendment: “This amendment allows Gilead to accelerate the domvanalimab program and enables Arcus to focus on progressing multiple pipeline assets, including both Gilead-optioned and non-optioned programs.” Parsey highlights the potential of these collaborations in transforming cancer treatment.

Gilead and Arcus have reprioritized their joint domvanalimab development program, focusing on the Phase 3 studies STAR-121 (lung cancer) and STAR-221 (gastrointestinal cancer), expected to be fully enrolled by year-end. The companies also plan to initiate STAR-131, a new Phase 3 lung cancer study involving the domvanalimab plus zimberelimab regimen.

Terry Rosen, CEO of Arcus, acknowledges the deepening partnership with Gilead since 2020. Rosen notes, “This investment and prioritization enable both companies to leverage their respective strengths and focus on efficiently advancing novel combinations that have the potential to change the landscape of cancer treatment.”

Notably, the partnership will discontinue further enrollment in the Phase 3 ARC-10 study, strategically prioritizing studies with higher unmet needs in lung and gastrointestinal cancers. This decision reflects the companies’ continued confidence in the TIGIT pathway and the unique properties of domvanalimab.

Additionally, the planned Phase 3 pancreatic cancer study evaluating quemliclustat will now be an independent Arcus study. This restructured collaboration is expected to extend Arcus’s financial runway into 2027, funding crucial Phase 3 studies in pancreatic and kidney cancer and preparing for potential product approvals.

Domvanalimab, zimberelimab, and quemliclustat remain investigational molecules, with their safety and efficacy for treating lung, gastrointestinal, and pancreatic cancers yet to be established.

A Fc-silent investigational monoclonal antibody, Domvanalimab targets the TIGIT protein on immune cells, potentially enhancing the immune response against cancer cells. It’s undergoing evaluation in three Phase 3 studies across lung and gastrointestinal cancers.

Zimberelimab, a potent anti-programmed cell death protein-1 (PD-1) monoclonal antibody, aims to restore the antitumor activity of T cells. It has gained approval in China for treating recurrent or metastatic cervical cancer and refractory classical Hodgkin’s lymphoma.

The amended collaboration and significant investment by Gilead Sciences in Arcus Biosciences represent a strategic move in the oncology sector. This partnership not only accelerates critical cancer research but also demonstrates a shared commitment to developing innovative therapies. The focus on domvanalimab and zimberelimab indicates a strong belief in their potential to advance cancer treatment, potentially leading to breakthroughs in patient care and therapeutic options.

  Arcus Biosciences, cancer, domvanalimab, Gilead Sciences, Merdad Parsey, Terry Rosen, zimberelimab