Recently introduced cancer immunotherapies unleash patients’ immune systems to attack cancers. In a study published online on January 7 in Proceedings of the National Academy of Sciences, senior author Niraj Shenoy, M.D., M.S., and collaborators report that combining high-dose ascorbic acid (vitamin C) with a class of immunotherapies called anti-PD1 checkpoint inhibitors bolsters anti-tumor activity in a lymphoma mouse model.

The study shows that high-dose ascorbic acid treatment increases the ability of lymphoma cells to provoke an immune response; enables CD8+ T cells and macrophages to better infiltrate tumors; and synergizes with anti-PD1 checkpoint inhibitors by markedly activating the immune system’s cytotoxic cells (cytotoxic T cells and NK cells) and antigen presenting cells. The findings provide a compelling rationale for testing combinations of high-dose ascorbic acid and anti-PD1 inhibitors in patients with aggressive B cell lymphoma and in preclinical models of other malignancies. The study was an extension of Dr. Shenoy’s prior research with ascorbic acid in cancer epigenetics published in Blood Cancer Journal, Journal of Clinical Investigation and Cancer Cell.

Dr. Shenoy is an assistant professor of medicine at Einstein and attending physician in oncology at Montefiore Einstein Center for Cancer Care. Rebecca Luchtel, Ph.D., the first author of the study, is a research assistant professor of medicine at Einstein.