Arcus Biosciences: late-line median survival 35 months

Median follow-up was three months for the first-line triplet cohort and 28 months across four pooled late-line monotherapy cohorts.

Rhea-AI Filing Summary

Arcus Biosciences, Inc. (RCUS) presented ARC-20 platform study data on casdatifan in clear cell renal cell carcinoma (ccRCC), covering first-line combinations, a second-line combination and late-line monotherapy. Data cutoff was September 4, 2026.

With first-line casdatifan plus zimberelimab (n=30), median follow-up was 11.5 months; confirmed objective response rate (cORR) was 50%, and landmark progression-free survival (PFS) was 86% at six months and 69% at 12 months. With casdatifan, ipilimumab and zimberelimab, one of 24 patients reaching a first scan had primary progression after three months of median follow-up; no unexpected safety signals were observed among 31 patients who received at least one dose.

In the second-line casdatifan plus cabozantinib cohort (n=43), after 21.3 months of median follow-up, median PFS was 14.5 months, 18-month landmark overall survival was 77%, cORR was 44%, and primary progression was 5%. Across four pooled late-line monotherapy cohorts (n=121), after 28 months of median follow-up, median overall survival was 35 months, median PFS was 13 months, and cORR was 36%. Monotherapy adverse events were described as acceptable and manageable.

8-K Event Classification

Item 8.01 — Other Events

1 item

Item 8.01 Other Events Other

Voluntary disclosure of events the company deems important to shareholders but not covered by other items.

Key Figures

Six-month landmark progression-free survival: 86% 12-month landmark progression-free survival: 69% Confirmed objective response rate: 50% +4 more

7 metrics

Six-month landmark progression-free survival 86% First-line casdatifan plus zimberelimab; n=30; median follow-up 11.5 months.

12-month landmark progression-free survival 69% First-line casdatifan plus zimberelimab; n=30; median follow-up 11.5 months.

Confirmed objective response rate 50% First-line casdatifan plus zimberelimab; n=30.

Median progression-free survival 14.5 months Second-line casdatifan plus cabozantinib; n=43; median follow-up 21.3 months.

18-month landmark overall survival 77% Second-line casdatifan plus cabozantinib; n=43.

Median overall survival 35 months Four pooled late-line casdatifan monotherapy cohorts; n=121; median follow-up 28 months.

Confirmed objective response rate 36% Four pooled late-line casdatifan monotherapy cohorts; n=121.

Key Terms

clear cell renal cell carcinoma, landmark progression-free survival, confirmed objective response rate, primary progression, +2 more

6 terms

clear cell renal cell carcinoma medical

"clear cell renal cell carcinoma (“ccRCC”)"

A type of kidney cancer that starts in the tubes of the kidney and is identified by tumor cells that appear clear under a microscope. Think of it as a distinct “breed” of kidney cancer with its own behavior and treatment options; that matters to investors because diagnosis rates, clinical trial outcomes, drug approvals, and treatment costs directly affect the market size and revenue prospects for companies developing therapies or diagnostics.

landmark progression-free survival medical

"landmark progression-free survival (“PFS”) was 86% and 69%"

confirmed objective response rate medical

"confirmed objective response rate (“cORR”) was 50%"

The confirmed objective response rate is the percentage of patients in a clinical trial whose tumors shrink or disappear by a predefined amount and then show that same response again on a subsequent assessment, confirming the change was real and not temporary. It matters to investors because it is a standard measure of a drug’s measurable activity against disease and is often used by regulators, analysts, and partners to gauge clinical progress and commercial potential—think of it as counting only treatment successes that pass a second check.

primary progression medical

"primary progression (progression at or before the first scan)"

immune-mediated adverse events medical

"Grade 3 and higher immune-mediated adverse events"

Immune-mediated adverse events are harmful side effects that occur when a treatment causes the body's immune system to overreact or mistakenly attack healthy tissues, similar to friendly fire. They matter to investors because such reactions can slow or stop regulatory approval, trigger costly additional testing or label warnings, and affect sales and legal risk, all of which can materially change a drug’s commercial prospects.

tyrosine kinase inhibitor medical

"tyrosine kinase inhibitor (“TKI”)"

A tyrosine kinase inhibitor is a type of drug that blocks specific proteins in cells that act like on/off switches for growth and survival signals, often used to stop cancer cells from multiplying. For investors, these drugs matter because their clinical trial results, regulatory approvals, safety profiles, and patent status drive sales potential and company valuation—think of them as precision tools whose effectiveness and market exclusivity determine commercial success.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What were RCUS’s second-line casdatifan and cabozantinib results?

The second-line casdatifan plus cabozantinib cohort had median PFS of 14.5 months, 18-month landmark overall survival of 77%, cORR of 44% and primary progression of 5%, with 21.3 months of median follow-up in 43 patients. Efficacy was similar whether or not patients had previously received TKI therapy.

What did RCUS report for late-line casdatifan monotherapy?

Across four pooled monotherapy cohorts (n=121), median overall survival was 35 months, median PFS was 13 months and cORR was 36%, after 28 months of median follow-up. PFS data were similar whether patients had received one, two or three prior TKI-inclusive treatments.

What safety findings did RCUS report for the first-line casdatifan triplet?

Among the 31 patients enrolled who received at least one dose of casdatifan, ipilimumab and zimberelimab, no unexpected safety signals were observed at data cutoff. Grade 3 and higher immune-mediated adverse events were generally consistent with those associated with ipilimumab and nivolumab in frequency, severity and timing.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 10/20/2026 - 08:33 AM EDT Accepted by SEC EDGAR 10/20/2026 - 08:33 AM EDT Learn about SEC filing dates

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

________________________________________________________

FORM 8-K

________________________________________________________

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 20, 2026

________________________________________________________

Arcus Biosciences, Inc.

(Exact name of Registrant as Specified in Its Charter)

________________________________________________________

Delaware

001-38419

47-3898435

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

3928 Point Eden Way

Hayward, California

94545

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: (510) 694-6200

(Former Name or Former Address, if Changed Since Last Report)

________________________________________________________

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
o			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
o			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
o			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, Par Value $0.0001 Per Share

RCUS

The New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Item 8.01 Other Events.

On October 20, 2026, Arcus Biosciences, Inc. presented new data from the ARC-20 platform study evaluating casdatifan, alone or in combination, as a first-, second- and late-line treatment for clear cell renal cell carcinoma (“ccRCC”). This presentation included the following data as of the data cutoff date of September 4, 2026:

First-line TKI-free combinations

•Casdatifan plus anti-PD-1 zimberelimab (n=30): with 11.5 months of median follow up, landmark progression-free survival (“PFS”) was 86% and 69% at six and 12 months, respectively, the confirmed objective response rate (“cORR”) was 50%, and the rate of primary progression (progression at or before the first scan) was 6.7%. No unexpected safety signals were observed at the time of data cutoff. The regimen showed safety data that are consistent with those observed in other cohorts or prior studies of each molecule.

•Casdatifan plus anti-CTLA-4 ipilimumab and zimberelimab: with three months of median follow up, only one patient out of 24 patients (4%) who had reached a first scan experienced primary progression. There were no unexpected safety signals observed in the 31 patients enrolled that received at least one dose of casdatifan plus ipilimumab and zimberelimab at the time of data cutoff. Grade 3 and higher immune-mediated adverse events were generally consistent with those associated with ipilimumab and nivolumab in frequency, severity and timing.

Second-line combination

•Casdatifan plus tyrosine kinase inhibitor (“TKI”) cabozantinib: with 21.3 months of median follow up (n=43), median PFS was 14.5 months, 18-month landmark overall survival was 77%, cORR was 44% and primary progression was 5%. Casdatifan plus cabozantinib demonstrated similar efficacy, whether or not patients previously received TKI therapy. TKI-pretreated patients represent approximately 60% of 2L patients in current practice and derive diminished benefit from subsequent TKI therapies. No unexpected safety signals were observed at the time of data cutoff (n=44). The regimen showed safety data that are consistent with those observed in other cohorts or prior studies of each molecule.

Late-line monotherapy

•Casdatifan monotherapy (n=121): with 28 months of median follow up in the four pooled monotherapy cohorts, median overall survival was 35 months, median PFS was 13 months and cORR was 36%. PFS data were similar whether patients had received one, two or three prior TKI-inclusive treatments. No unexpected safety signals were observed, and casdatifan showed acceptable and manageable adverse events across all doses.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

			ARCUS BIOSCIENCES, INC.
Date: October 20, 2026			By:			/s/ Terry Rosen, Ph. D.
						Terry Rosen, Ph.D.
						Chief Executive Officer (Principal Executive Officer)

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