Arcus Biosciences pipeline update: casdatifan, quemliclustat, domvanalimab

Key Takeaways

• PRISM-1 (NCT06608927) compares quemliclustat + nab-paclitaxel + gemcitabine vs placebo + chemo in metastatic PDAC; status active not recruiting; estimated enrollment 610.
• Primary endpoint is overall survival; study start 13 December 2024; estimated completion 30 November 2030 (ClinicalTrials.gov).
• STAR-221 / NCT05568095 tests domvanalimab + zimberelimab + chemo vs nivolumab + chemo in unresectable/metastatic upper GI adenocarcinoma; enrollment 1,040.
• Casdatifan remains investigational; cite SEC/ClinicalTrials.gov rather than unverified ORR anecdotes when updating models.

What is the quemliclustat Phase 3 design?

ClinicalTrials.gov NCT06608927 (PRISM-1) is a randomized, double-blind Phase 3 study sponsored by Arcus Biosciences comparing quemliclustat with nab-paclitaxel and gemcitabine versus placebo with the same chemotherapy in metastatic pancreatic ductal adenocarcinoma.

• Status: Active not recruiting.
• Estimated enrollment: 610.
• Primary outcome: overall survival (up to 72 months).
• Start: 13 December 2024.

What does the domvanalimab GI Phase 3 test?

NCT05568095 randomizes domvanalimab + zimberelimab + FOLFOX/CAPOX versus nivolumab + chemo in locally advanced unresectable or metastatic gastric, GEJ and esophageal adenocarcinoma. Listed enrollment is 1,040; status active not recruiting.

Where does casdatifan sit?

Casdatifan (AB521) is Arcus’s HIF-2α inhibitor program in clear-cell renal cell carcinoma. Treat conference ORR figures as preliminary until Phase 3 PEAK-1 or related registry pages confirm design and endpoints. Prefer Arcus SEC EDGAR filings for cash runway and partnership language.

How should analysts weight Gilead collaboration risk?

Historical SEC exhibits describe a multi-year Gilead option collaboration covering several Arcus molecules. Option decisions and shared costs change peak-year ownership—read the latest 10-K/10-Q rather than recycling 2023 quotes.

What catalysts matter in 2026–2027?

Watch PRISM-1 event accrual, any STAR-221 topline disclosures, and new casdatifan Phase 3 postings. Do not assume positive OS without a primary-source release or registry update.

What remains unproven in the Arcus stack?

None of quemliclustat, domvanalimab or casdatifan has established FDA-approved efficacy for the Phase 3 settings above as of this writing. Safety and efficacy remain investigational until labeling exists.

How should 2026 models treat Arcus biosciences pipeline risk?

Arcus biosciences pipeline models for 2026–2027 should haircut quemliclustat until PRISM-1 (NCT06608927) posts OS events. With estimated enrollment 610, start date 13 December 2024, and primary completion projected toward 2030, near-term valuation hinges on interim disclosures—not on 2024 ARC-20 ORR anecdotes alone.

For domvanalimab, NCT05568095 lists 1,040 participants. Any 2026 topline must state the comparator (nivolumab plus chemo) and whether futility rules fired. Casdatifan Phase 3 timing belongs in a separate RCC line with SEC cash-runway footnotes.

Cash and partnership footnotes in 2024–2025 SEC filings still matter in 2026: option decisions can re-cut U.S. economics even if NCT06608927 enrollment stays at 610. Keep a dated memo with the three NCT IDs above and the latest 10-Q cash figure before changing peak-year models.

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Frequently Asked Questions

Primary Sources

1. ClinicalTrials.gov NCT06608927 (PRISM-1)
2. ClinicalTrials.gov NCT05568095 (STAR-221)
3. SEC EDGAR: Arcus Biosciences CIK 0001724521
4. FDA: drug development and approval process