Russia’s Enteromix Cancer Vaccine Shows Promise in Early Trials — But Not 100% Effective Yet

Russia has developed a personalized cancer vaccine called Enteromix, which has demonstrated high effectiveness and safety in preclinical studies and Phase I human trials.

Development and Preclinical Results

Enteromix is being developed by the National Medical Research Radiological Centre (NMRRC) in collaboration with the Engelhardt Institute of Molecular Biology under the Russian Academy of Sciences. The vaccine completed several years of regulated preclinical testing during which it reduced tumor growth and, in some cases, completely destroyed tumors in animal models. It also showed survival benefits and maintained safety profiles in repeated dosing studies.

Working Mechanism

Enteromix is not an mRNA vaccine, as some media reports have incorrectly claimed. It operates as an oncolytic vaccine, using a combination of four engineered non-pathogenic viruses. These viruses both directly kill malignant cells and stimulate the patient’s anti-tumor immune response. This dual mechanism engages innate immunity via viral oncolysis while activating adaptive immune responses, creating a comprehensive defense against cancer.

Russia is also developing a separate mRNA-based cancer vaccine, but this is a different program and should not be confused with Enteromix.

Clinical Trial Progress

Phase I clinical trials began in mid-2025, enrolling 48 volunteers in an open-label, single-center study at the St. Petersburg International Economic Forum. Interim reports note low toxicity and good tolerability among participants.

Reports of “100% success” are misleading. Officials announced that all patients mounted some immune response, which was incorrectly translated in media coverage as “100% efficacy.” In reality, tumor shrinkage was observed in around 60–80% of patients in early findings. Phase I trials are designed primarily to test safety, not to measure effectiveness.

Regulatory Status and Expansion Plans

Veronika Skvortsova, head of Russia’s Federal Medical and Biological Agency, stated that clinical documentation has been submitted to the Ministry of Health, and the vaccine is “ready for use,” pending regulatory approval. Enteromix will initially be applied to colorectal cancer, with development efforts also underway for glioblastoma and melanoma, including ocular melanoma.

Need for Further Evidence

Experts like Dr. Manan Vora, MBBS, MCh Orthopedics from The University of Edinburgh, caution that Phase I trials focus on safety, not definitive efficacy. No peer-reviewed scientific studies have been published yet, and experts emphasize that larger Phase II and III trials will be required before any conclusions can be drawn.

Simple Summary

• What it does: Enteromix combines four safe viruses to kill cancer cells and boost the body’s immune response against tumors.

• Current stage: It has shown encouraging results in animal studies and an early human trial, with no serious side effects reported.

• Next steps: Russian regulators are reviewing it, and further clinical trials are needed to establish its effectiveness across larger and more diverse populations.

  (Rh/Eth/TL/MSM)