In the relentless quest for groundbreaking cancer therapies, innovative drug trials are reshaping treatment landscapes and redefining patient hope. Arcus Biosciences Inc. ( RCUS ) on Monday announced new monotherapy data for casdatifan in late-line metastatic clear cell renal cell carcinoma (ccRCC).

ARC-20 is a Phase 1/1b dose-escalation and expansion study with four monotherapy cohorts (n=121): 50mg twice daily (BID), 50mg once daily (QD), 100mg QD (tablet), and 150mg QD.

New Casdatifan Data

In the 100mg tablet cohort, Phase 3 dose and formulation, casdatifan showed a 35% confirmed overall response rate (ORR), with two additional responses pending confirmation, and median progression-free survival (mPFS) had not been reached, even with a median follow-up of one year.

Pooled data for the 121 patients treated with casdatifan monotherapy, casdatifan showed a confirmed ORR of 31% and a median PFS of 12.2 months, which is meaningfully longer than published data from studies with the only marketed HIF-2a inhibitor and for TKIs alone in a similar patient population and setting, the company said on Monday.

At the time of data cut-off (Aug. 15, 2025), most patients (81%) had experienced disease control, with either a partial response or stable disease. Seventy-four percent (28 of the 38) of confirmed responders across all four cohorts remained on treatment.

No unexpected safety signals were observed, and casdatifan had an acceptable and manageable safety profile across all doses.

Across all four cohorts, one patient discontinued treatment due to anemia, and four (3%) discontinued due to hypoxia. Summaries of the efficacy and safety data are below.

Expansion into Immunology and Inflammation (I&I): Potential new drug candidates include:

MRGPRX2 small-molecule inhibitor, a potential treatment for atopic dermatitis and chronic spontaneous urticaria.

TNF-a (TNFR1) small-molecule inhibitor, a potential treatment for rheumatoid arthritis (RA), psoriasis, and inflammatory bowel disease (such as ulcerative colitis).

CCR6 small-molecule inhibitor, a potential treatment for psoriasis

CD89 monoclonal antibody, a potential treatment for RA.

CD40L small-molecule inhibitor, a potential treatment for multiple sclerosis and systemic lupus erythematosus.

RCUS Price Action: Arcus Biosciences ( RCUS ) shares were up 7.87% at $14.40 at the time of publication on Monday. The stock is trading within its 52-week range of $6.50 to $18.98, according to Benzinga Pro data.

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