FDA Extends Review of Exelixis' Zanzalintinib Plus Tecentriq in Metastatic Colorectal Cancer to March 2027
核心洞察
The FDA extended its review of Exelixis' NDA for zanzalintinib plus atezolizumab in metastatic colorectal cancer (搜索) by three months, setting a new PDUFA date of March 3, 2027.
The extension followed Exelixis' submission of updated safety and efficacy data in response to an FDA information request, which the agency classified as a major amendment.
The filing is based on the Phase 3 STELLAR-303 trial, where the combination reduced the risk of death by 20% versus regorafenib in the intent-to-treat population.
The U.S. Food and Drug Administration (搜索) has extended its review of Exelixis' New Drug Application for zanzalintinib in combination with atezolizumab (Tecentriq) for previously treated metastatic colorectal cancer (搜索) (mCRC) by three months, pushing the updated Prescription Drug User Fee Act (PDUFA) action date to March 3, 2027. The prior target decision date was December 3, 2026, and a March decision would push a possible U.S. launch out of this year and into 2027.
According to the company's filing, the FDA requested additional information, and Exelixis responded with updated safety and efficacy data, which the agency classified as a major amendment to the application. The revised PDUFA date reflects the standard three-month extension applied when an applicant submits new data during an ongoing review cycle.
STELLAR-303 Efficacy Data
The NDA is based on the Phase 3 STELLAR-303 trial, which randomized 901 patients 1:1 to zanzalintinib plus atezolizumab or regorafenib in previously treated non-microsatellite instability (non-MSI)-high mCRC. The combination demonstrated a statistically significant 20% reduction in the risk of death versus regorafenib in the intention-to-treat (ITT) population (stratified hazard ratio: 0.80; 95% confidence interval: 0.69–0.93; P=0.0045), with median overall survival (OS) of 10.9 months versus 9.4 months. The results were presented at the 2025 European Society for Medical Oncology Congress and published in The Lancet.
The trial carried dual primary OS endpoints — one in the full ITT population and one in patients without active liver metastases (non-liver metastases, NLM). The ITT endpoint was met, but the final NLM analysis reported in June 2026 produced a non-statistically significant trend favoring the combination (hazard ratio: 0.83; 95% CI: 0.66–1.05; P=0.1185), with median OS of 15.9 versus 12.7 months. The FDA accepted the NDA in February 2026 on the basis of the ITT result, covering the broader previously treated mCRC population.
The FDA accepted the application for adults with metastatic colorectal cancer (搜索) who had already received standard chemotherapy; patients whose tumors lacked a common RAS (搜索) mutation also had to have tried a separate targeted drug first. Friday's filing did not state whether the new data requested by the FDA came from the NLM subgroup.
Mechanism and Positioning
Zanzalintinib is an oral kinase inhibitor that targets the TAM kinases (搜索) (TYRO3, AXL, MER), MET, and VEGF receptors (搜索). Exelixis designed the molecule as a successor to its approved cabozantinib (Cabometyx), with an improved pharmacokinetic half-life. The combination with atezolizumab, a PD-L1 (搜索) checkpoint inhibitor, is intended to reduce immune evasion through TAM kinase blockade while suppressing angiogenesis.
In the late-line mCRC setting, approved options include regorafenib, trifluridine/tipiracil (Lonsurf), and fruquintinib (Fruzaqla). For the BRAF V600E (搜索)-mutant subset, encorafenib-based regimens are approved. The combination of nivolumab and ipilimumab is approved for MSI-high or mismatch repair-deficient CRC, a population excluded from STELLAR-303. Zanzalintinib plus atezolizumab would represent a chemotherapy-free option targeting the larger non-MSI-high population, where STELLAR-303 is described as the first Phase 3 trial to demonstrate a statistically significant overall survival improvement with an immunotherapy-based regimen.
Analyst Perspective
William Blair (搜索) wrote on Friday, "While we are surprised by the three-month delay, we believe the risk of rejection remains low, given that the combination of zanzalintinib plus Tecentriq demonstrated an overall survival (OS) benefit across the intent-to-treat population in the Phase 3 STELLAR-303 study." The firm kept an 'Outperform' rating and said the extra wait should not materially cut the drug's long-term sales, though the stock may swing more in the near term.
Analyst Andy Hsieh acknowledged the challenge of pinpointing the regulator's exact motives but outlined three plausible reasons for the request: regulators might require additional clinical data comparing the 100 mg dose against the 60 mg dose of zanzalintinib; health officials could be seeking clearer evidence regarding the individual therapeutic contributions of zanzalintinib and Tecentriq; or regulators may be addressing a specific technical query not previously highlighted during earlier review phases.
Commercial and Market Context
Zanzalintinib is Exelixis's bid for a second commercial franchise after Cabometyx, the cabozantinib tablet that still accounts for nearly all of the company's product sales. Cabometyx is approved for kidney, liver, and neuroendocrine cancers and generated about $2.12 billion in U.S. net product revenue in 2025.
Exelixis shares were down 1.81% to $56.39 at the time of publication on Friday, according to Benzinga Pro data, with other reports citing a roughly 2% decline. On Stocktwits, retail sentiment around EXEL stock fell from 'neutral' to 'bearish' over the past 24 hours, while message volume rose from 'normal' to 'high' levels. EXEL stock has gained 28% year-to-date.
Broader Zanzalintinib Development Program
Beyond the mCRC filing, Exelixis is running multiple zanzalintinib pivotal trials, including STELLAR-304 in non-clear cell renal cell carcinoma, STELLAR-311 in neuroendocrine tumors, and STELLAR-316 in resected stage II/III CRC, the latter in collaboration with Merck (搜索) and Natera.