Arcus Biosciences (NYSE:RCUS) used its fourth-quarter and full-year 2025 earnings call to highlight updated clinical data for its lead oncology program, casdatifan, and to outline near-term plans for late-stage development in clear cell renal cell carcinoma (ccRCC). Management also discussed an emerging inflammation and immunology (I&I) portfolio and provided 2026 financial guidance.
Casdatifan data update ahead of ASCO GU
CEO Terry Rosen and Chief Medical Officer Richard Markus emphasized Arcus’s goal of establishing casdatifan as a “best-in-class” HIF-2? inhibitor for ccRCC. The company said updated results from the ARC-20 study will be presented at ASCO GU, including efficacy and biomarker data intended to further differentiate casdatifan from belzutifan, the only marketed HIF-2? inhibitor.
- Confirmed ORR (100 mg QD cohort): increased from 35% at an August cutoff to 45%.
- Confirmed ORR (pooled analysis): increased from 31% to 35%.
- Median PFS (100 mg QD cohort): 15.1 months after 17.8 months median follow-up; Markus added that even if all censored patients progressed at the next scan, median PFS would still be 14.4 months.
- Median PFS (pooled analysis): remained 12.2 months, with patients continuing treatment beyond 12 months and even beyond 24 months.
Management compared those outcomes to belzutifan data from LITESPARK-005, citing a 5.6-month PFS figure for belzutifan in the same late-line setting, and argued that casdatifan monotherapy has shown longer progression-free survival and higher response rates.
Phase III plans: PEAK-1 and a TKI-sparing frontline strategy
Arcus’s first Phase III casdatifan study, PEAK-1, is evaluating casdatifan plus cabozantinib versus cabozantinib alone in immunotherapy-experienced ccRCC. Markus said PEAK-1 is actively enrolling and described it as a “fast-to-market strategy,” with a sole primary endpoint of PFS that could enable a relatively quick readout. Rosen added that the company’s goal is to complete PEAK-1 enrollment by year-end.
Rosen and Markus also repeatedly returned to a broader strategic objective: developing a TKI-free or TKI-sparing regimen in the frontline setting. Rosen argued that a key differentiator for casdatifan is a consistently low “primary progression” rate (progression at or before first scan), which management described as especially important early in therapy. He contrasted this with belzutifan’s reported primary progression rate of 35% as monotherapy in its Phase III trial, arguing belzutifan will likely require combination with a TKI in frontline disease to keep early progression low.
Arcus said it is using ARC-20 as a platform study to inform dose selection and combination strategy, noting that 100 mg once daily has been selected as the “optimal go-forward dose” and that the study design supports adding new cohorts efficiently across approximately 30 active sites in four countries.
Near-term clinical catalysts and benchmarking discussions
On the call, Rosen said the company expects “at least two” additional casdatifan data presentations later in 2026, including updated results from the casdatifan plus cabozantinib cohort with a minimum of 12 months follow-up on all patients, and new data from the ARC-20 casdatifan plus “Zim” cohort intended to establish casdatifan plus anti-PD-1 as a frontline backbone. Markus said Arcus plans to share data from the “CAS plus Zim” cohort in the second half of the year.
In Q&A, management pointed investors to ipilimumab/nivolumab as a key frontline benchmark for a TKI-sparing strategy. Rosen cited primary progression of about 20%–25% and PFS of roughly 12 months for ipilimumab/nivolumab, referencing CheckMate 214 and COSMIC-313 as trials where outcomes were “very, very similar.” Arcus said it wants to demonstrate “meaningful improvement,” with particular emphasis on reducing the primary progression rate.
Arcus also addressed an AstraZeneca collaboration evaluating casdatifan with volrustomig, an anti-PD-1/CTLA-4 bispecific, noting the study had been paused and volrustomig was dosed down while patients continued on casdatifan. Rosen said no additional immune-related adverse events had been seen since the dose reduction and said the company observed no primary progression in the small dataset, but he did not provide an update on whether the paused run-in would reopen.
Separately, management said it expects detailed results from Merck’s Phase III LITESPARK-011 (belzutifan plus lenvatinib versus cabozantinib) to be presented at ASCO GU and suggested the data could be “validating” and supportive of enrollment momentum for PEAK-1, which uses the same control arm. Rosen also stated that Merck’s KEYMAKER-U02A presence at ASCO GU is a “trial in progress” poster without belzutifan data.
Market opportunity commentary
Chief Commercial Officer Jen Liao framed RCC as a multi-billion-dollar opportunity, stating that RCC drug sales in select major markets exceed $10 billion annually and are anticipated to grow to $13 billion by 2030. She said HIF-2? inhibition is “the only new class” on the horizon and characterized the field as a “2-horse race” between belzutifan and casdatifan.
Liao also stated that belzutifan—approved in late-line ccRCC—is already generating an annual run rate of “nearly $1 billion.” She outlined Arcus’s focus on earlier lines of therapy and presented internal peak sales estimates for casdatifan, including $2.5 billion in the IO-experienced setting targeted by PEAK-1 and $3 billion or more in first line, while emphasizing these represent a revenue opportunity to Arcus rather than total addressable market. She also noted Arcus retains rights to casdatifan economics except in Japan and certain Southeast Asian countries.
Immunology pipeline and financial update
Chief Scientific Officer Juan Jaen described Arcus’s I&I portfolio as comprising five programs, with a focus on validated targets where small molecules have historically been difficult to develop. He highlighted an MRGPRX2 antagonist and a TNF inhibitor as the two most advanced programs expected to reach the clinic first. Jaen said the MRGPRX2 program is expected to enter the clinic later this year, beginning with a healthy volunteer Phase I study and then a proof-of-concept study in chronic inducible urticaria, with potential proof-of-concept data within nine to 12 months after clinical entry. For the TNF program, he said Arcus is aiming for a selective TNF receptor 1 approach and expects to enter the clinic in late 2026 or early 2027.
On financials, CFO Bob Go said Arcus ended the fourth quarter with $1.0 billion in cash, up from $841 million at the end of the third quarter, aided by a $288 million financing in November. The company reported:
- GAAP revenue: $33 million in Q4 (vs. $26 million in Q3), primarily driven by its Gilead collaboration.
- R&D expenses: $121 million in Q4 (vs. $141 million in Q3).
- G&A expenses: $26 million in Q4 (vs. $27 million in Q3).
- Stock-based compensation (non-cash): $15 million in Q4 (vs. $14 million in Q3).
For 2026, Arcus guided to $45 million to $55 million in full-year GAAP revenue and said it expects operating expenses to decrease meaningfully versus 2025. Go said the magnitude of the decrease could depend on the results of a forthcoming futility analysis for STAR-121, expected in the “next couple of months,” with more detailed R&D guidance to come on the Q1 call. Arcus expects its cash and investments to fund operations until at least the second half of 2028.
About Arcus Biosciences (NYSE:RCUS)
Arcus Biosciences is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel cancer immunotherapies. The company’s research platform centers on modulating tumor microenvironments and immune checkpoints through both small-molecule and antibody-based candidates. Arcus aims to enhance antitumor immune responses by targeting pathways such as the adenosine axis and inhibitory receptors on immune cells.
The company’s lead clinical programs include etrumadenant, an orally administered A2A adenosine receptor antagonist being evaluated in combination with anti-PD-1 therapy, and domvanalimab, an anti-TIGIT monoclonal antibody.
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