EGF-depleting vaccine plus nivolumab shows survival signal in advanced NSCLC

A single-arm phase II trial has reported that adding CIMAvax-EGF, a therapeutic vaccine that depletes circulating epidermal growth factor, to the PD-1 inhibitor nivolumab produced encouraging survival outcomes in patients with previously treated, immunotherapy-naïve advanced non-small cell lung cancer.

CIMAvax-EGF works through an unusual mechanism: rather than attacking tumor cells directly, it induces antibodies against EGF itself, clearing the free growth factor from the bloodstream and thereby starving EGF-dependent signaling in tumors. In the trial (NCT02955290), patients received 2.4 mg of the vaccine intramuscularly every two weeks for four loading doses, followed by monthly maintenance, while nivolumab was administered at 240 mg intravenously every two weeks. Overall survival and progression-free survival were estimated with Kaplan–Meier methods and 95% confidence intervals.

Twenty-one patients completed the loading phase and formed the per-protocol population. In this group, the disease control rate was 47.6%, corresponding to ten patients. Median overall survival was 11.9 months, with 48% of per-protocol patients alive at 12 months and 29% surviving to three years. The authors report that these outcomes compared favorably with historical cohorts of nivolumab monotherapy, although the single-arm design means such comparisons are not randomized and should be interpreted with caution.

A striking pattern emerged when outcomes were stratified by tumor genotype. Patients whose tumors were wild-type for EGFR, ALK and KRAS had a median overall survival of 31.7 months, with 67% alive at one year and 50% at three years. In contrast, patients with KRAS-mutated tumors had a median overall survival of 10.1 months, with 29% surviving one year and none reaching three years. This pattern suggests that the benefit of the combination may concentrate in tumors without these driver mutations.

The trial also generated a translational finding that may help explain the observed survival differences. Using serum samples collected from individual patients after vaccination, the researchers tested the ability of post-vaccination sera to inhibit EGFR phosphorylation. This capacity correlated with survival: patients whose sera showed greater inhibition of EGFR phosphorylation had a longer median overall survival of 11.3 months, compared with 6.5 months among those with lesser inhibition. The result links the vaccine’s pharmacodynamic effect on EGF signaling with clinical outcome, although it derives from a small sample and a correlative analysis.

The authors conclude that combining CIMAvax-EGF with PD-1 blockade is feasible and may have additive activity, particularly in EGFR/ALK/KRAS wild-type NSCLC. Because the trial was single-arm and small, with survival compared against historical rather than concurrent controls, the findings are hypothesis-generating rather than practice-changing. Randomized studies would be needed to establish whether the combination genuinely extends survival over nivolumab alone, and in which molecular subgroups. Nevertheless, the survival correlation with EGFR phosphorylation inhibition offers a measurable biomarker that could guide patient selection in future trials of this EGF-depleting approach.

Subject of Research: A phase II trial combining the EGF-depleting vaccine CIMAvax-EGF with nivolumab in previously treated, immunotherapy-naïve advanced NSCLC

Article Title: Phase II study of CIMAvax EGF plus nivolumab in previously treated, immunotherapy-naïve advanced NSCLC

Article References: Frascati, R., Gudkov, A., Reid, M. E., Lee, K., Muhitch, J. B., Mesa, C., Luaces, P. L., Santos-Morales, O., Bespalov, I. A., Minderman, H., Tario, J. D., Fitzpatrick, V., Dozier, A., Ford, C., Liu, X., Fountzilas, C., Gandhi, S., Attwood, K., Groman, A., … Dy, G. K. (2026). Phase II study of CIMAvax EGF plus nivolumab in previously treated, immunotherapy-naïve advanced NSCLC. Cancer Immunology, Immunotherapy. https://doi.org/10.1007/s00262-026-04615-5

Image Credits: AI Generated

DOI: 10.1007/s00262-026-04615-5

Keywords: CIMAvax-EGF, nivolumab, NSCLC, phase II trial, EGF depletion, overall survival, PD-1 blockade, KRAS mutation, EGFR phosphorylation, immunotherapy, lung cancer, biomarker