Sacituzumab Govitecan Plus Pembrolizumab Misses Primary Endpoints in First-Line PD-L1-High Metastatic NSCLC
核心洞察
Phase 3 EVOKE-03/KEYNOTE-D46 found sacituzumab govitecan plus pembrolizumab did not significantly improve progression-free survival versus pembrolizumab alone in PD-L1 (搜索)-high metastatic NSCLC.
Median progression-free survival was 11.8 months with the combination versus 7.7 months with pembrolizumab alone, but the result missed the prespecified significance threshold.
Interim overall survival was 21.5 months with the combination versus 22.8 months with monotherapy, with grade 3 or higher treatment-related adverse events in 55.7% versus 16.5% of patients.
The Phase 3 EVOKE-03/KEYNOTE-D46 trial has failed to show a statistically significant progression-free survival benefit for sacituzumab govitecan plus pembrolizumab compared with pembrolizumab alone as first-line treatment for patients with metastatic non-small cell lung cancer (搜索) (NSCLC) and a PD-L1 (搜索) tumor proportion score (TPS) of 50% or greater. Primary results were presented at the International Association for the Study of Lung Cancer (搜索) (IASLC) 2026 World Conference on Lung Cancer (WCLC) in Seoul, Republic of Korea.
The trial tested whether adding an antibody-drug conjugate to standard first-line immunotherapy could displace pembrolizumab monotherapy in a population selected for strong predicted responsiveness to checkpoint inhibition. It did not.
Trial Design and Patient Population
EVOKE-03/KEYNOTE-D46 is an open-label Phase 3 study that enrolled 620 patients with previously untreated metastatic NSCLC, a PD-L1 (搜索) TPS of at least 50%, and no EGFR, ALK or ROS1 alterations. Those molecular subgroups were excluded because they are typically managed with targeted therapies rather than immunotherapy alone.
Participants were randomized to receive sacituzumab govitecan at 10 mg/kg intravenously on days 1 and 8 plus pembrolizumab 200 mg intravenously on day 1 of each 21-day cycle, or pembrolizumab alone. The dual primary endpoints were progression-free survival (PFS) by blinded independent central review and overall survival (OS).
Progression-Free Survival Falls Short of Significance
Median PFS by blinded independent central review was 11.8 months with sacituzumab govitecan plus pembrolizumab compared with 7.7 months with pembrolizumab alone (HR, 0.81; 95% CI, 0.66-1.00; P=0.0252). Although PFS was numerically longer with the combination — roughly four additional months without disease progression — the result did not meet the prespecified threshold for statistical significance required by the trial design.
Interim Overall Survival Leans Toward Monotherapy
At the interim analysis, median overall survival was 21.5 months with the combination and 22.8 months with pembrolizumab alone (HR, 1.07; 95% CI, 0.85-1.35; P=0.7155). Overall survival was not significantly improved with the addition of the antibody-drug conjugate, and the point estimate leaned slightly in favor of monotherapy.
Response Rates Higher, Response Duration Unchanged
Secondary measures of tumor response favored the combination. The confirmed objective response rate was 55.6% with sacituzumab govitecan plus pembrolizumab versus 43.7% with pembrolizumab alone. The disease control rate reported in the study table was 83.3% versus 73.1%, respectively. Median duration of response was nearly identical between arms at 21.4 months versus 21.3 months, indicating that the combination induced responses in more patients but did not prolong the responses that occurred.
Substantially Higher Toxicity With the Combination
Treatment-related adverse events occurred in 93.2% of patients receiving the combination and 65.4% of those receiving pembrolizumab alone. Grade 3 or higher treatment-related adverse events occurred in 55.7% and 16.5% of patients, respectively — a more than threefold increase in severe toxicity.
The most common treatment-related adverse events in the combination arm included anemia, alopecia, neutropenia, diarrhea and nausea, a profile consistent with the known toxicity signature of sacituzumab govitecan. The safety profile was consistent with the known profiles of the individual agents, with no new or additional toxicities observed with the combination.
Investigator Interpretation
"While the combination of sacituzumab govitecan and pembrolizumab produced a numerically longer progression-free survival and a higher response rate, EVOKE-03/KEYNOTE-D46 did not meet statistical significance for its primary PFS endpoint, and overall survival was not significantly improved at this interim analysis," said Giannis Mountzios, M.D., of the Henry Dunant Hospital Center, Athens, Greece. "These findings provide important information as we continue to evaluate treatment strategies for patients with PD-L1 (搜索)-high metastatic NSCLC."
Dr. Mountzios concluded that, despite a numerical improvement in PFS and a higher response rate, sacituzumab govitecan plus pembrolizumab did not meet statistical significance for PFS compared with pembrolizumab monotherapy in patients with untreated PD-L1 (搜索)-high metastatic NSCLC, and that overall survival also did not meet statistical significance at the interim analysis.
Rationale Behind the Combination Strategy
Sacituzumab govitecan links a topoisomerase I inhibitor payload to an antibody targeting TROP-2 (搜索), a protein widely expressed on many epithelial cancers, including a substantial proportion of non-small cell lung tumors. The drug has already secured regulatory approvals in previously treated metastatic settings. Combining antibody-drug conjugates with immune checkpoint inhibitors has become one of the most active areas of clinical research, based on the hypothesis that chemotherapy payload-induced tumor cell death can release antigens and render tumors more visible to the immune system. Pembrolizumab, an anti-PD-1 (搜索) antibody, is the established first-line standard for metastatic NSCLC with PD-L1 (搜索) TPS of 50% or greater when no targetable alterations are present.
The results leave pembrolizumab monotherapy in its longstanding position as the reference standard for this population, while raising questions about whether the modest numerical gains in progression-free survival justify the substantially higher toxicity burden and the absence of any demonstrated survival benefit at this interim analysis.
The IASLC, founded in 1974, is the only global organization dedicated solely to the study of lung cancer and other thoracic malignancies, with a membership of more than 10,000 lung cancer specialists across all disciplines in over 100 countries. It publishes the Journal of Thoracic Oncology and convenes the WCLC, the world's largest meeting dedicated to lung cancer and other thoracic malignancies, which attracts nearly 7,000 researchers, physicians and specialists from more than 100 countries each year.