Exelixis Inc. (EXEL): STELLAR-303 NLM subgroup misses on OS

Research evidence excerpt

Exelixis Inc. (EXEL): STELLAR-303 NLM subgroup misses on OS

Equity Research

22 June 2026 | 12:32PM EDT

NLM subpopulation statistically shows a trend but misses in the final analysis; Paul Choi

+1(212)902-5217 | paul.k.choi@gs.com

PDUFA and commercial impact likely limited. EXEL shares are modestly Goldman Sachs & Co. LLC

underperforming (down -1.3% vs. XBI: +3.5% intraday) following the announcement Daniel Ni, Ph.D.

that final analysis of the dual primary endpoint in the NLM (non-liver metastases) +1(212)902-2365Goldman Sachs & Co.| daniel.ni@gs.comLLC

patients subset from the Phase 3 STELLAR-303 pivotal trial evaluating zanzalintinib +

atezolizumab in 3L+ metastatic-colorectal cancer (mCRC) did not reach statistical

significance. Specifically, the company reported the zanza + atezo combo showed a

non-statistically significant trend in OS favoring the combination in the NLM

subpopulation with HR of 0.83 (95% CI: 0.66–1.05; P=0.1185). The median OS of the

combo arm was 15.9 vs 12.7 months with regorafenib. Overall, we see the results

mildly disappointing but as unlikely to affect the upcoming PDUFA nor the

commercial opportunity in later line mCRC. Recall, the STELLAR-303 study was

designed with a dual primary endpoint trial of OS in the ITT population and in the

NLM subgroup of patients (i.e., one positive result from the dual endpoints is needed

to deem the overall trial a success). As such, from a statistical perspective, the trial

remain valid in meeting the primary endpoint. Additionally, as the ITT endpoint was

met, which includes both the non-NLM and NLM populations, we think physicians

would still have the flexibility to prescribe the combo therapy to both populations

when they see fit, if the combo therapy is approved. Ahead, we look for more