Arcus Biosciences (RCUS) Morgan Stanley 22nd Annual Global Healthcare Conference summary

Pipeline and clinical data updates

• AB521 (Casdatifan), a HIF-2alpha inhibitor, will have new data presented later this year, focusing on a 100 mg cohort in clear cell RCC, with over 30 patients and endpoints including primary progression rate, ORR, and PFS.

• The 100 mg cohort is the go-forward dose for phase III, with data showing a substantially better primary progression rate than belzutifan; 50 mg and 150 mg cohorts are also being studied, with the 150 mg data expected next year.

• Patient population in the 100 mg cohort is more advanced than in comparator studies, with 25% having received four or more prior lines of therapy.

• The PEAK-1 phase III trial will use Cabo as the combination partner, targeting IO-experienced clear cell RCC patients, aiming for rapid enrollment due to high interest.

• Additional studies are planned for frontline settings and other combinations, with more details expected in the coming weeks.

Strategic partnerships and financials

• Gilead's opt-in decision for the program is expected around year-end or early next year, with a 50-60 day window after data delivery; the recent debt facility is unrelated and extends runway into mid-2027.

• Collaboration with Gilead remains strong and operationally seamless, regardless of CMO transitions.

• Development plans for Casdatifan are set to proceed with or without Gilead's opt-in, and there is external interest in the program.

TIGIT program and competitive landscape

• Domvanalimab (Dom), an Fc-silent anti-TIGIT, is differentiated from Fc-enabled competitors, with mature ARC-10 and ARC-7 data expected to be positive and address prior concerns about control arm performance.

• The STAR-121 phase III lung cancer trial is fully enrolled, comparing domzim chemo to Keytruda chemo, with interim analyses not disclosed.

• The STAR-221 gastric cancer study is fully enrolled and could be the first anti-TIGIT approval, targeting a $3B+ market with dual primary endpoints for broad patient inclusion.

• The competitive threat from TROP-2 and LAG-3 is seen as limited, and confidence is high in the potential for first-to-market in lung cancer.