Advaxis, Inc. announced an update on the Phase 1 clinical study evaluating ADXS-504, the company's off-the-shelf neoantigen drug candidate, in patients with biochemically recurrent (early) prostate cancer that is being conducted at Columbia University Irving Medical Center. Karie Runcie, MD, assistant professor of medicine, and Mark N. Stein, MD, associate professor of medicine, in the division of hematology/oncology at Columbia University Vagelos College of Physicians and Surgeons and members of the Herbert Irving Comprehensive Cancer Center, are the study's principal and senior investigators, respectively. The study design of this phase 1 open-label dose escalation study for patients in both dose cohorts was presented at the 2022 ASCO Annual Meeting by Dr. Runcie (Abstract #: TPS5115).

The clinical assessment of three patients at the first dose level (1e7 CFU) and three at the second dose level (1e8 CFU) has shown that ADXS-504 monotherapy is safe and well-tolerated. In this study, ADXS-504 is being administered via infusion every four weeks for a total of six doses, followed by four additional maintenance doses every twelve weeks, in patients with biochemically recurrent prostate cancer, i.e., those with elevation of prostate-specific antigen (PSA) in the blood after radical prostatectomy or radical radiotherapy (external beam or brachytherapy) and who are not currently receiving androgen ablation therapy. Patients have experienced mild and short-lived flu-like symptoms after the infusion of ADXS-504 at both the first and second dose levels.

The trial is currently expanding enrollment at the second dose level by up to six additional patients for a total of nine patients. The study investigators will evaluate the immunogenicity data after all of the patients at the higher dose level have completed the study treatment. ADXS-504 is a novel Lm-based immunotherapy, bioengineered to elicit T cell responses against 24 tumor antigens, including 14 peptide antigens derived from hotspot mutations in patients with prostate cancer and 10 peptide antigens derived from sequence-optimized tumor-associated antigens (TAAs) that are differentially expressed or overexpressed in prostate cancer.

ADXS-504 is designed to express multiple tumor antigen targets, potentially leading to generation of a broad set of effector T cells and NK cells that may enhance tumor control. Similar to Advaxis's other Lm-based immunotherapies, ADXS-504 is expected to induce an innate immune response followed by the adaptive response and modification of the immunosuppressive tumor microenvironment (TME) by reducing regulatory T cells (Tregs) and myeloid- derived suppressor cell (MDSC) frequencies in the TME. The safety of ADX-504 and encouraging early data led to decision to increase enrollment at the second dose level to better characterize its clinical activity.