A groundbreaking study from Duke Health reveals that a cancer vaccine trial conducted over 20 years ago has resulted in all participating women with advanced breast cancer remaining alive, a remarkable outcome for metastatic disease. This long-term survival draws attention to the potential of enhancing cancer vaccines, particularly through a key immune signal known as CD27.
The original trial, led by Herbert Kim Lyerly, M.D., the George Barth Geller Distinguished Professor of Immunology at Duke University School of Medicine, included a small group of women diagnosed with advanced breast cancer. Researchers investigated the immune systems of these women and discovered that they retained powerful immune cells capable of recognizing their cancer even after two decades. These cells exhibited a specific marker called CD27, which is crucial for the immune system’s memory and response to past threats.
Zachary Hartman, Ph.D., the senior author of the study, expressed surprise at the durability of these immune responses so many years later. He stated, “It made us ask: What if we could boost this response even more?” This inquiry led to further investigations into the role of CD27 in enhancing cancer vaccine efficacy.
Laboratory Experiments Yield Promising Results
To explore the potential of CD27, the research team conducted experiments with mice, combining a vaccine targeting HER2—a protein often found on breast cancer cells—with an antibody designed to activate CD27. The results were striking; nearly 40% of the mice that received this combined treatment experienced complete tumor regression. In contrast, only 6% of those treated with the vaccine alone showed similar outcomes.
The study revealed that the CD27 antibody significantly boosted the activity of CD4+ T cells, a type of immune cell often referred to as “helper” cells. According to Hartman, CD4+ T cells are frequently overlooked in cancer research, with most studies focusing on CD8+ “killer” T cells. This research suggests that the helper cells are equally important, aiding in the development of lasting immune memory and enhancing the effectiveness of other immune responses.
Implications for Future Cancer Treatment
Interestingly, the findings indicate that the CD27 antibody only needs to be administered once alongside the vaccine to maintain long-lasting effects. This simplicity could facilitate the integration of this approach with existing cancer treatments such as immune checkpoint inhibitors and antibody-drug conjugates currently in use.
Hartman believes this research could help unlock the full potential of cancer vaccines, stating, “We’ve known for a long time that vaccines can work against cancer, but they haven’t lived up to the hype. This could be a missing piece of the puzzle.” The study received funding from the National Institutes of Health and the Department of Defense.
The results of this study, published in Science Immunology, pave the way for future research into cancer vaccines and their potential to significantly improve patient outcomes. As researchers continue to explore the dynamics of the immune system, the hope is that strategies like enhancing CD27 could transform the landscape of cancer treatment, offering new hope to patients facing metastatic disease.
