BioVaxys Reports Positive Phase 1 Results for Cancer Immunotherapies in Breast and Bladder Cancer
Key Insights
BioVaxys announced positive Phase 1 results for maveropepimut-S (MVP-S) combined with letrozole in hormone receptor positive HER2 negative breast cancer (search), showing all three patients achieved at least 50% reduction in Ki67 (search) proliferation marker.
The company also reported successful Phase 1 outcomes for both MVP-S and DPX-SurMAGE vaccines in non-muscle invasive bladder cancer (search), with 55% of MVP-S patients and 33% of DPX-SurMAGE patients showing significant T cell responses.
Both studies demonstrated the safety and tolerability of BioVaxys' DPX platform-based immunotherapies, which target survivin (search) and MAGE-A9 (search) cancer antigens to generate sustained immune responses.
BioVaxys Technology Corp (search). has announced positive Phase 1 clinical results for two of its cancer immunotherapies, demonstrating promising efficacy signals in both breast and bladder cancer (search) patients. The Vancouver-based biotechnology company reported successful outcomes for its maveropepimut-S (MVP-S) vaccine in hormone receptor positive HER2 negative breast cancer (search) and for both MVP-S and DPX-SurMAGE vaccines in non-muscle invasive bladder cancer (search).
Breast Cancer Study Shows Strong Anti-Tumor Activity
In a Phase 1 study led by Dr. Sasha Stanton at the Earle A. Chiles Research Institute, Providence Cancer Center, three postmenopausal patients with HR+/HER2- breast cancer (search) and Ki67 (search) levels >10% received two doses of MVP-S combined with seven weeks of neoadjuvant letrozole prior to surgery.
All three patients achieved at least a 50% decrease in Ki67 (search) between biopsy and surgery, with median levels dropping from 24% (range 12% to 43%) before treatment to 6% (range 5% to 8%) after treatment. The Ki-67 marker measures cancer cell proliferation, with elevated scores indicating more aggressive tumors.
One patient demonstrated an 8-fold increase of survivin (search)-specific circulating Interferon-gamma (IFN-γ) T cells at surgery, indicating robust immune activation. IFN-γ is a critical messenger molecule that promotes effective cell-mediated immune responses against cancer.
The global market for HER2-negative breast cancer (search) was valued at $14.4 billion in 2024 and is projected to reach $21.5 billion by 2030, with HR+/HER2- tumors representing the largest subgroup at 57.77% of total revenue share.
Bladder Cancer Trial Demonstrates Dual-Target Approach
The company also reported results from a Phase 1 study in non-muscle invasive bladder cancer (search) (NMIBC) led by Dr. Yves Fradet at Université Laval. The two-arm study evaluated 12 patients who had failed intravesical therapy, with 9 patients receiving MVP-S (targeting survivin (search) only) and 3 patients receiving DPX-SurMAGE (targeting both survivin and MAGE-A9 (search)).
Both treatments were well tolerated and induced significant systemic antigen-specific T cell responses. Among MVP-S recipients, 55% showed significant responses that peaked at Day 28, while 33% of DPX-SurMAGE patients demonstrated significant responses that were stronger at Day 49.
"Despite the small number of patients tested, we were very impressed by the strength and duration of the T cell responses to a combination of immunogenic peptides against two molecules with very distinct biological activity," noted Dr. Fradet.
After an average two years of follow-up, many patients remained free of recurrence, suggesting potential clinical benefit. The global bladder cancer (search) market is projected to grow from $3 billion in 2023 to $16 billion in 2033, with NMIBC treatments for BCG-unresponsive patients driving growth.
DPX Platform Technology
Both studies utilized BioVaxys' proprietary DPX platform, which delivers antigens through a novel "no release" mechanism. Rather than releasing active ingredients at the injection site, the platform forces active uptake by immune cells and delivery to lymphatic nodes, creating sustained T cell activation over longer durations than traditional vaccines.
MVP-S delivers antigenic peptides from the survivin (search) family, well-recognized cancer antigens commonly overexpressed in advanced cancers, along with an innate immune activator and universal CD4+ T cell helper peptide. DPX-SurMAGE combines survivin peptides with MAGE-A9 (search) antigens to target two distinct cancer pathways simultaneously.
Clinical Development Plans
Kenneth Kovan, President and Chief Operating Officer at BioVaxys, stated: "We are very encouraged by the positive clinical data from this study, as the use of MVP-S together with neoadjuvant hormone therapy could lead to a treatment for women with hormone receptor positive HER2 negative Stage II-III breast cancer (search)."
The company plans to pursue Phase 2 studies for both indications. For breast cancer (search), BioVaxys and Dr. Stanton will conduct expanded profiling of biopsy samples compared to post-treatment surgical samples to support Phase 2 development. For bladder cancer (search), the results warrant further investigation in a Phase 2 trial as a potential alternative to current intravesical and systemic treatments.
The successful dual-antigen approach with DPX-SurMAGE also validates the platform's ability to package and deliver multiple dissimilar antigens, supporting development of new multivalent vaccines for both cancer and infectious diseases.