Anixa Biosciences, Inc. has announced the presentation of final data from the phase 1 clinical trial of its investigational breast cancer vaccine at the 2025 San Antonio Breast Cancer Symposium (SABCS).
The trial was conducted in collaboration with Cleveland Clinic and funded by a grant from the U.S. Department of Defense.
Final phase 1 findings showed the investigational vaccine met all major primary endpoints, was safe and well tolerated at the maximum tolerated dose (MTD), and elicited protocol-defined immune responses in 74% of participants. The presentation, “Final Results of a Phase I Trial of Alpha-lactalbumin (aLA) Vaccine for Breast Cancer,” was delivered by Justin Johnson, program manager at Cleveland Clinic and co-inventor of the breast cancer vaccine technology.
“Triple-negative breast cancer remains one of the most challenging subtypes to address, and phase 1 trials are an important step in determining whether a new approach can be administered safely and activate the immune system as intended,” said G. Thomas Budd, of Cleveland Clinic’s Cancer Institute and principal investigator of the study.
“In this trial, the investigational α-lactalbumin vaccine was safe and well tolerated at the maximum tolerated dose and generated protocol-defined immune responses in 74% of participants—results that support continued clinical evaluation.”
All major primary endpoints were met, with 74% of participants demonstrating protocol-defined immune responses. α-lactalbumin (aLA)-specific T cell responses were observed per protocol-defined criteria.
The vaccine was safe and well tolerated at the MTD, with adverse events primarily injection-site irritation. Preliminary Immunohistochemistry (IHC) of primary tumours showed aLA expression ranging from absent to strong; analyses correlating expression to immune response and clinical outcomes are ongoing. Participants will be followed for five years after completing the study.
The combination of Keytruda and the vaccine also generated antigen-specific T cell responses and showed no major additional side effects.
Data will inform planned phase 2 study design, including a potential phase 2 combination study with Keytruda in the neoadjuvant setting among newly-diagnosed breast cancer patients.
The phase 1 study evaluated safety and monitored immune response to an investigational vaccine targeting α-lactalbumin (aLA). The trial enrolled 35 participants across three cohorts: Cohort Ia, women who completed standard-of-care treatment, including surgery, for early-stage TNBC within three years and were tumour-free but at elevated risk of recurrence; Cohort Ib, cancer-free women with BRCA1, BRCA2, or PALB2 mutations who elected preventive mastectomy and were vaccinated prior to surgery; and Cohort Ic, women with TNBC receiving pembrolizumab (Keytruda) in the adjuvant (post-surgery) setting, with evaluation of safety of combination administration and immune responses.
In Cohort Ia, at the MTD, the vaccine was reported as safe, with no flu-like symptoms (fever and myalgias), no abnormal clinical laboratory tests, and no other observed adverse side effects in this cohort; the primary notable adverse event was injection-site irritation. Participants demonstrated aLA-specific T cell responses, including production of interferon gamma and interleukin-17.
In Cohort Ib, safety and tolerability were similar to Cohort Ia. Immunohistochemistry analyses of resected breast tissue are ongoing and will be presented in a future scientific presentation.
In Cohort Ic, a key objective was to assess whether administration of the investigational vaccine in combination with pembrolizumab could create intolerable side effects. No major adverse side effects were reported; as in other cohorts, the primary adverse event was injection-site irritation. Two participants experienced Grade 3 adverse events consisting of greater irritation at an injection site.
The investigational vaccine targets α-lactalbumin, a lactation protein generally expressed in the breast during lactation but not at other times in life or in other normal tissues. In many breast cancers, malignant cells express α-lactalbumin. The vaccine is designed to activate the immune system to direct cytotoxic T cells toward tumour cells expressing α-lactalbumin, with the goal of providing pre-emptive immune protection against emerging tumours that express this antigen.
The vaccine is based on preclinical research led by the late Vincent Tuohy, who served as the Mort and Iris November Distinguished Chair in Innovative Breast Cancer Research at Cleveland Clinic.
“It was Dr. Tuohy’s hope that this vaccine would demonstrate the potential of immunization as a new way to combat breast cancer, and that a similar approach could someday be applied to other types of malignancies,” Johnson said.
“Our findings that the majority of participants across all three cohorts demonstrated an immune response to α-lactalbumin is an encouraging sign.”
Amit Kumar, chairman and CEO of Anixa Biosciences, said: “We are very encouraged that the final phase 1 data met all major primary endpoints, with the vaccine demonstrating a favourable tolerability profile at the MTD and protocol-defined immune responses in the majority of participants. We appreciate the support provided through the U.S. Department of Defense grant that enabled this study in collaboration with Cleveland Clinic, and we look forward to engaging with regulators and advancing plans for a phase 2 study.”
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