Gilead Sciences, Inc. (Nasdaq: GILD) and Arcus Biosciences, Inc. (NYSE: RCUS) have announced an amendment to their collaboration agreement, along with a separate equity investment by Gilead of $320 million in Arcus common stock at $21.00 per share. This equity investment and collaboration amendment aim to expedite the growth of the joint development programs between the companies, spanning multiple indications.
Johanna Mercier, Chief Commercial Officer at Gilead Sciences, will also join the Arcus Board, increasing Gilead’s total director designees to three. The amendment includes governance enhancements to facilitate streamlined decision-making, reflecting the ongoing expansion of the collaboration.
The amended collaboration allows Gilead to accelerate the domvanalimab program and permits Arcus to concentrate on advancing various pipeline assets, including both Gilead-optioned and non-optioned programs. The companies plan to prioritize the joint domvanalimab development program, focusing on advancing Phase 3 studies STAR-121 (lung cancer) and STAR-221 (gastrointestinal cancer), both expected to be fully enrolled by year-end. The companies also plan to initiate STAR-131, a new registrational Phase 3 lung cancer study that includes the domvanalimab plus zimberelimab regimen.
This prioritization aims to leverage the TIGIT pathway and the Fc-silent design of domvanalimab, potentially differentiating it in both efficacy and safety.
The collaboration amendment and equity investment provide financial support for Arcus, extending its cash runway into 2027, enabling the funding of Phase 3 studies of quemliclustat in pancreatic cancer and AB521 in kidney cancer, as well as preparations for potential product approvals.
As part of the prioritization, the Phase 3 ARC-10 study evaluating domvanalimab plus zimberelimab compared to pembrolizumab monotherapy in first-line locally advanced or metastatic, PD-L1-high NSCLC will be discontinued. Patients enrolled in ARC-10 may continue their treatment according to the study protocol.
The planned Phase 3 first-line study in pancreatic cancer evaluating the investigational small molecule CD73 inhibitor quemliclustat will become an independent Arcus study under the amended collaboration agreement.
Both Gilead and Arcus expressed gratitude to the patients and investigators involved in ARC-10, with a commitment to sharing data and insights generated by the study at future scientific conferences. Domvanalimab, zimberelimab, and quemliclustat are investigational molecules, and neither company has received regulatory approval for their use in treating lung, gastrointestinal, or pancreatic cancers, with the safety and efficacy yet to be established.
