Does the FDA approve Exelixis's zanzalintinib for colorectal cancer?
Will the FDA approve Exelixis's zanzalintinib, in combination with atezolizumab, for previously treated metastatic colorectal cancer by its March 3, 2027 PDUFA target action date (extended three months from the original December 3, 2026 date)?
A genuine coin-flip-adjacent call — sell-side analysts see low rejection risk on the merits, but the FDA's own three-month extension to request more data is a real cautionary signal that keeps this from being a clear 'yes'
The case for approval: STELLAR-303 showed a statistically significant overall survival benefit in its primary analysis, William Blair's analysts believe rejection risk remains low given the broadly positive data, and Exelixis changed nothing about the underlying trial results when the FDA asked for updated data. The case against: the FDA's extension request itself signals unresolved questions, the trial missed statistical significance on a dual-primary-endpoint subgroup analysis, severe adverse events ran notably higher on zanzalintinib (59%) than on regorafenib (37%), and Leerink has flagged a real risk the agency excludes the non-liver-metastatic subgroup from any approved label.
Resolves Mar 3, 2027 · PDUFA target action date for Exelixis's NDA covering zanzalintinib plus atezolizumab in previously treated metastatic colorectal cancer, based on Phase 3 STELLAR-303 data; extended three months from the original Dec 3, 2026 date after the FDA requested updated efficacy and safety data
The FDA accepted Exelixis's NDA for standard review on Feb 2, 2026, based on the Phase 3 STELLAR-303 trial, which showed zanzalintinib plus atezolizumab improving overall survival over regorafenib (stratified hazard ratio 0.80; median OS 10.9 vs. 9.4 months) in previously treated, non-MSI-high metastatic colorectal cancer. On Sept 11, 2026, Targeted Oncology reported the FDA extended the PDUFA date by three months, to March 3, 2027, to review updated efficacy and safety data Exelixis submitted — the agency gave no public reason beyond needing more time. The trial missed significance on one of its dual primary endpoints in a subgroup, and severe or life-threatening adverse events occurred in 59% of the zanzalintinib arm versus 37% on regorafenib. William Blair's analysts have characterized overall rejection risk as low given the broadly positive data, while Leerink has flagged a risk the FDA could carve out the non-liver-metastatic subgroup from any approval.
The FDA either approves the combination by its PDUFA date or it issues a Complete Response Letter, requests more data, or otherwise does not approve by then — a discrete regulatory action with no partial outcome.
Researched Oct 27, 2026 · tracked since Oct 27, 2026
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FDA approves zanzalintinib for mCRCthis is “yes”
STELLAR-303 showed a statistically significant overall survival benefit in its primary analysis, William Blair's analysts believe rejection risk remains low given the broadly positive data, and nothing about the underlying trial results changed when the FDA requested updated data.
Worth knowing: The FDA's own three-month extension to review updated efficacy and safety data is a real cautionary signal — extensions sometimes precede a Complete Response Letter rather than a straightforward approval.
FDA delays or rejects the application
The trial missed statistical significance on a dual-primary-endpoint subgroup analysis, severe adverse events ran notably higher on zanzalintinib (59%) than on regorafenib (37%), and Leerink has flagged a real risk the agency excludes the non-liver-metastatic subgroup from any approved label.
Worth knowing: William Blair and other sell-side analysts have characterized the extension as administrative rather than substantive — don't read the delay alone as strong evidence of an impending CRL.
5 sources, leaning both ways
- mixedOncLive — FDA Accepts NDA for Zanzalintinib Plus Atezolizumab in Pretreated mCRCChecked Oct 27: confirms the Feb 2, 2026 FDA acceptance of the NDA under standard review with the original Dec 3, 2026 PDUFA date, based on STELLAR-303.
- yesExelixis (ir.exelixis.com) — NDA acceptance press releaseChecked Oct 27: Exelixis's own primary-source confirmation of FDA acceptance and the regulatory timeline this topic tracks.
- noTargeted Oncology — FDA Delays Decision on Zanzalintinib Combo for mCRCChecked Oct 27: reports the FDA's Sept 11, 2026 three-month PDUFA extension to March 3, 2027, to review updated efficacy and safety data — the clearest source of this topic's bear case.
- mixedFierceBiotech — FDA delays approval decision for Exelixis' tyrosine kinase inhibitor in colorectal cancerChecked Oct 27: covers the PDUFA delay while citing William Blair's view that overall rejection risk remains low given the promising Phase 3 data.
- noFierceBiotech — Exelixis' Cabometyx successor fails primary endpoint colorectal cancer trial amid FDA reviewChecked Oct 27: details the dual-primary-endpoint subgroup miss and the elevated severe-adverse-event rate (59% vs. 37% for regorafenib) underlying the bear case.