(Patients with disseminated metastatic disease from breast cancer are likely to have liver involvement in >50% of cases at some point during disease progression. These patients have poor prognosis; and, when treated with the standard of care systemic therapy they have a median survival of <9-months.)
June 17, 2025, (Syracuse, New York) — Zetagen Therapeutics, a private, clinical-stage, biopharmaceutical company developing first-of-its-kind targeted therapies for primary and metastatic breast cancer, announced today the peer-reviewed publication in PLOS-One of their dose optimization in-vivo study results of ZetaMast™ (Zeta-MBC-005).
Zetagen identified two concentrations of ZetaMast™ (Zeta-MBC-005) which demonstrated superior effectiveness, reduction in tumor burden, and increased survival rate over control Doxorubicin.
“Patients with disseminated metastatic breast cancer involving the liver, face a poor prognosis and new approaches are urgently needed., stated Debasish Tripathy, MD, Professor and Chairman, Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX “Although some therapies have been designed for direct administration for liver metastases, they have not demonstrated efficacy in significantly improving survival. ZetaMast™ is an innovative therapeutic approach that has demonstrated systemic biological effects potentially extending beyond liver metastases in preclinical models, offering promising potential to enhance outcomes in this setting.”
ZetaMast™ (Zeta-MBC-005) Increased Survival in a Mouse Xenograft Liver Metastases Model. The 4T1, TNBC cell line, tagged with luc2 luciferase (4T1-luc2), was implanted directly into the liver of BALB/c mice. Seven days after tumor inoculation, mice were treated with various concentrations via a single administration of ZetaMast™ (Zeta-MBC-005) (30-, 60-, 120-, 180-, 240-, or 480-μg) in combination with 5-mg/kg doxorubicin. Mice in the Control group received 5 mg/kg of doxorubicin and the ZetaMast™ (Zeta-MBC-005) carrier without Zetagen’s small molecule, administered every72-hours.
ZetaMast™ (Zeta-MBC-005) has the ability to deliver Zetagen’s small molecules intratumorally as well as other therapies, avoiding off-target side effects.
“Effective locoregional therapies are likely the key to reducing breast cancer mortality for patients with disseminated metastatic disease and increasing 5-year survival above 31%. If treatments like ZetaMast™ (Zeta-MBC-005) can be given when and where needed, increasing the duration of overall tumor control, which may be enough to tip the balance towards a favorable impact on survival.,” stated Bryan S. Margulies, MS, Ph.D., CSO of Zetagen.
To view the ZetaMAST™ (Zeta-MBC-005) dose optimization study results go to https://doi.org/10.1371/journal.pone.0323621.
ZetaMast™ (Zeta-MBC-005) is a proprietary drug eluting carrier designed for locoregional administration, controlled release of two small molecules in the treatment of multifocal, unresectable, liver metastases from breast cancer with the potential to increase survival rates.
The USPTO has granted Zetagen a “Composition of Matter” patent for ZetaMast™ (Zeta-MBC-005), and Zetagen has also submitted a filing to the FDA for Orphan Drug Designation.
Zetagen is finalizing preparations for an FDA IND submission this fall, with a Phase Ib clinical trial set to commence early 2026.
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Zetagen has three novel drugs in development, ZetaMet™ (Zeta-BC-003), for the treatment of metastatic breast cancer to bone, ZetaMast™ (Zeta-MBC-005) for breast cancer liver metastases (BCLM), and (NEW) ZetaPrime™ (Zeta-PBC-007) for the treatment of primary HR+ breast cancer, all with inspiring results. To learn more, visit www.zetagen.com.
The FDA has acknowledged Zetagen’s innovative research with multiple Breakthrough Designations, notably ZetaMet™ (Zeta-BC-003). Under FDA and Health Canada (HC) approval through the Expanded Access (Compassionate Use) programs, Zetagen has treated eight patients with ZetaMet™ (Zeta-BC-003), with results featured in several peer-reviewed journals. Furthermore, Zetagen has completed enrollment for its Phase 2a open-label clinical trial focused on treating metastatic breast cancer in the spine.
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