November 14, 2023— A small clinical trial conducted by researchers at Washington University School of Medicine in St. Louis has shown promising results for the experimental vaccine meant to avert the recurrence of triple-negative breast cancer.
The Phase I clinical trial involved 18 patients diagnosed with triple-negative breast cancer that had not metastasized. Each participant received the standard of care—surgery, chemotherapy, and radiation therapy—followed by three doses of a personalized neoantigen DNA vaccine. This vaccine was tailored to target specific mutations unique to each patient’s tumor, training their immune systems to recognize and attack cancer cells bearing these mutations.
The vaccine was found to be well-tolerated, with minimal side effects reported. Fourteen of the 18 patients exhibited immune responses to the vaccine, and after three years of follow-up, 16 patients remained cancer-free. While the trial was primarily designed to assess the safety of the vaccine rather than its efficacy, these results are encouraging when compared to historical data, which suggests that approximately half of patients with similar diagnoses remain cancer-free three years after treatment.
“These results were better than we expected,” said Dr. William E. Gillanders, the senior author of the study and the Mary Culver Distinguished Professor of Surgery at Washington University School of Medicine. ““Obviously, it’s not a perfect comparison, and we acknowledge the limitations of this type of analysis, but we are continuing to pursue this vaccine strategy and have ongoing randomized controlled trials that do make a direct comparison between the standard of care plus a vaccine versus the standard of care alone. We are encouraged by what we’re seeing with these patients so far.”
Outlook and Future Implications
To patients struggling with triple-negative breast cancer—an especially aggressive form of the disease with few treatment options—new hope comes with these early trial outcomes. The development of personalized vaccines is a landmark in cancer therapy and signals the move to customized medicine, where treatment matches the person’s genetic composition.
As this research moves forward into larger and more comprehensive trials, there’s hope that this vaccine could become a standard part of treating triple-negative breast cancer. If it proves effective in these bigger studies, it could significantly improve survival rates and offer a new, much-needed defense against the cancer coming back.
Even more hearteningly, the viability of such individualized vaccination may be a pointer to related treatments being applicable in other forms of cancer. Based on the exploitation of one’s exclusive tumor mutations to activate responses of the immune system, this technique brings the hope to produce very specific medicine options able to realize fewer adverse effects than ordinary therapies.
About Washington University School of Medicine
Washington University School of Medicine in St. Louis was founded in 1891 and has been committed to disseminating medical knowledge and enhancing public health. The medical school at Washington University in St. Louis is recognized for its excellence in general education, research, and care given to patients. This institution has solidified its position among the nation’s top centers, particularly in the areas of medical investigation, primary health care provision, and treatment of patients suffering from diseases.
