Breast Cancer Vaccine Study Shows Positive Results

A clinical trial funded by the U.S. Department of Defense that evaluated an alpha-lactalbumin (aLA) vaccine demonstrated an immune response in 74 percent of patients who presently have or are at high risk for triple-negative breast cancer (TNBC). The trial evaluated 35 patients across three cohorts:

Phase Ia, which evaluated patients who finished standard-of-care treatment for early-phase TNBC in the past three years and had no remaining tumors but remained at high risk of recurrence;

Phase Ib, which evaluated patients who did not have cancer but carried genetic mutations for breast cancer risk and opted for a preventive bilateral mastectomy (study of this cohort is ongoing to evaluate toxicity in the breast tissue); and

Phase Ic, which evaluated patients with early-stage TNBC who received surgery and chemotherapy followed by immunotherapy pembrolizumab but had residual disease that increased their risk of recurrence.

Patients enrolled in the study received a total of three aLA vaccinations, administered once every two weeks. They had blood draws at days 14, 28 and 56 after the first vaccination to gauge cellular response using enzyme-linked immunosorbent spot (ELISpot) and antibody response using enzyme-linked immunosorbent (ELISA) assays. Researchers also examined the breast tissue of patients in the Phase Ib cohort to check for inflammatory or occult lactational foci changes.

Resulted showed DL1 (10 (mcg) is the maximum tolerated dose, which produced an immune response in most patients. Of the patients who received this dose, all experienced grade 1 toxicity, which were injection site reactions. Study co-author G. Thomas Budd, MD, noted that the research team set a low bar for an acceptable level of side effects since adverse events need to be low for vaccines that may be used as a preventive strategy.

Based on the results of the Phase I trial, the new study sponsor, Anixa Biosciences Inc. plans to open the Phase II study late in 2026.