TNBC Vaccine Shows Promising Safety, Immune Response in Phase 1 Trial

Breast cancer, female anatomy: © peterschreiber.media - stock.adobe.com

An investigational breast cancer vaccine for triple-negative breast cancer (TNBC) showed encouraging results, with over 70% of patients exhibiting protocol-defined immune responses, according to findings from a phase 1 trial (NCT04674306) presented at the Society for Immunotherapy of Cancer (SITC) 39th Annual Meeting.¹

The α-lactalbumin vaccine demonstrated safety, tolerability, and immune activation across all 3 patient cohorts. Specifically, across all cohorts, the vaccine was well tolerated, with injection site irritation as the primary adverse event (AE). No major systemic AEs were observed, including in combination with pembrolizumab (Keytruda).

The maximum-tolerated dose has been successfully identified; however, additional dosages are being evaluated. Now, a phase 2 trial in the neoadjuvant setting is planned in patients with newly diagnosed breast cancer and set to begin in 2025.

“Triple-negative breast cancer is the form of the disease for which we have the least effective treatments," said G. Thomas Budd, MD, of Cleveland Clinic's Cancer Institute and principal investigator of the phase 1 study, in a press release. "Long term, we are hoping that this can be a true preventive vaccine that would be administered to individuals who are cancer-free to prevent them from developing this highly aggressive disease."

The phase 1 trial was conducted in collaboration with Cleveland Clinic and funded by the US Department of Defense.² Investigators evaluated the α-lactalbumin vaccine in 3 patient cohorts. Cohort 1a included women who were previously treated for TNBC (n = 21), cohort 1b included women at high genetic risk of TNBC undergoing prophylactic mastectomies (n = 2), and cohort 1c consisted of patients with TNBC receiving the vaccine alongside pembrolizumab (n = 3).

Primary end points of the study were to evaluate the MTD across cohorts, and secondary end points sought to determine the lowest immunologic dose of α-lactalbumin vaccine across cohorts.

For cohort 1a, the vaccine was safe and tolerable with strong immune responses noted.1 A similar safety profile was observed among those in cohort 1b, and enrollment and tissue analysis for this cohort is ongoing. Further, there were no major AEs from combination therapy seen in cohort 1c, and confirmed immune responses were noted.

With antigen-specific T-cell responses confirmed and no major AEs seen in women receiving the vaccine and pembrolizumab, experts plan to further assess the vaccine in a phase 2 study in the neoadjuvant setting for the potential treatment of patients with newly diagnosed breast cancer.

"We are pleased with the data we have observed in this clinical trial. The data continues to exceed our expectations. As we near completion of the phase 1 trial, with the very positive data to date, we are planning a phase 2 study which is expected to commence in 2025," stated Amit Kumar, PhD, chairman and chief executive officer of Anixa Biosciences, in a press release. "We want to thank all of the participants in this trial and also the extensive group of scientists and physicians (19 are listed as co-authors of the SITC presentation) who have worked on this study, along with the numerous additional personnel including nurses, pharmacists, phlebotomists and others who have provided support."

REFERENCES

1. Anixa Biosciences and Cleveland Clinic present new updated positive data from phase 1 study of breast cancer vaccine at the 39th Society for Immunotherapy of Cancer (SITC) Annual Meeting. News release. Anixa Biosciences, Inc. November 8, 2024. Accessed November 20, 2024. https://tinyurl.com/486scakv

2. Adjuvant therapy with an alpha-lactalbumin vaccine in triple-negative breast cancer. ClinicalTrials.gov. Updated November 19, 2024. Accessed November 20, 2024. https://clinicaltrials.gov/study/NCT04674306?tab=table