Arcus Biosciences Highlights Casdatifan Data at Citi Summit

Arcus Biosciences presented its clinical progress for casdatifan, a HIF-2α inhibitor, at a Citi investor summit on September 9, 2026, signaling strong momentum ahead of upcoming data releases. The company’s late-line monotherapy program, Project Optimist, demonstrated a progression-free survival (PFS) of 12 to 15 months—substantially outperforming Merck’s belzutifan, which achieved 5.6 months in its pivotal LITESPARK-005 trial. Casdatifan’s pharmacokinetics offer a fivefold pharmacodynamic advantage over belzutifan’s 120 mg cap, with late-line doses yielding effects ranging from 2.5 to 7.5 times belzutifan’s efficacy in 120 evaluated patients. The company also highlighted a 7% primary progression rate in its frontline combination cohort with zimberelimab (anti-PD-1), compared to Merck’s belzutifan plus lenvatinib’s 14.7-month PFS in LITESPARK-011 and a 18% progression rate in ipilimumab/nivolumab’s CheckMate 214 benchmark. Arcus’ second-line study, PEAK-1, with 44 enrolled patients, is expected to deliver interim data by October 2024, while its frontline Phase III trial, ARC-20, is set to begin enrollment in late 2024 or early 2025. The company’s stock, trading at $28.44 as of the summit, has surged 157% over the past year, reaching a 52-week high of $31.73. With a market capitalization of $3.6 billion, Arcus targets a $4 billion or more first-line opportunity for casdatifan, roughly twice the size of its second-line potential, which could reach $1.5 billion to $2 billion. Competitor belzutifan’s late-line monotherapy sales run at about $1 billion annually. Arcus CEO Bob Goeltz emphasized overall survival as a key differentiator, noting it would bolster commercialization prospects in both the U.S. and international markets. The company anticipates interim OS data for Project Optimist by late 2028 or early 2029, following PEAK-1’s mid-2028 readout. A fourth-quarter 2024 interim analysis for its CD73 inhibitor, quemliclustat, in pancreatic cancer is also expected. Arcus’ pipeline includes early-stage immunology programs, such as its MRGPRX2 inhibitor, alongside ongoing efforts to refine casdatifan’s frontline and combination strategies.