The funding round closed with strong demand from private investors—led by JSTAR Capital Investments—demonstrating deep confidence in our clinical efficacy.

SYRACUSE, N.Y.–(BUSINESS WIRE)–Zetagen Therapeutics, Inc., a privately held, clinical-stage biopharmaceutical company pioneering first-of-its-kind, intratumoral treatments for metastatic and primary breast cancer, today announced the successful closure of its Series B1 financing round of $12,908,000. The round was 100% oversubscribed, reflecting strong investor confidence in the company’s proprietary Zeta Platform and its potential to transform breast cancer care.

Proceeds from this round will support the advancement of Zetagen’s lead candidate, ZetaMet™ (Zeta-BC-003) towards commercialization, accelerate clinical development of ZetaMast™ (Zeta-MBC-005), and complete preclinical studies & GMP manufacturing of ZetaPrime™ (Zeta-PBC-007).

“The strong demand in our Series B1 round highlights the promise of our Phase 2a clinical data for ZetaMet in treating metastatic breast cancer to bone,” said Joe C. Loy, CEO of Zetagen Therapeutics. “At the core of these encouraging results is our discovery of a novel molecular pathway—triggered by our compounds activating a conserved nuclear receptor—which enables promising predictability in dosing and outcomes from bench to bedside.”

Advancing the Zeta Platform

Zetagen’s Zeta Platform is the development of first-of-its-kind therapies for metastatic and primary breast cancer. Our novel approach via proprietary carriers with a singular injection, delivers tumoricidal compounds which minimize severe off-target side effects while increasing survival rates.

The platform includes:

• ZetaMet™ (Zeta-BC-003): Targets metastatic breast cancer in bone, ceasing lytic activity, inhibiting pain, and regenerating new bone, all via a singular intratumoral injection, without systemic limitation, minimizing skeletal related events (fractures). We have completed a Phase 2a clinical trial at the University of British Columbia demonstrated Complete Response in treated lesions, full bone regeneration, and no skeletal-related events. Preliminary results to be presented at the upcoming SABCS conference.
• ZetaMast™ (Zeta-MBC-005): is a novel hydrogel delivering two synergistic tumoricidal agents via a single intratumoral injection for breast cancer liver metastases (BCLM). Designed to localize treatment and reduce systemic toxicity, it has shown promising preclinical results—published in PLOS ONE and co-authored by Dr. Debu Tripathy—demonstrating reduced tumor burden, prevention of soft tissue metastases, and improved survival. A Phase 1b dose-escalation study is planned for 1H-2026.
• ZetaPrime™ (Zeta-PBC-007): a neo-adjuvant treatment engineered for intratumoral administrationfollowing diagnosis. Utilizing proprietary hydrogel-like lipid carrier, formulation enables controlled release of 2 small molecules—one being novel molecular entity and or the ability to deliver a CDK4 or CDK4/6 protein inhibitor. Designed for solubility within adipose tissue, approach targets primary breast cancer, aiming to mitigate off-target effects, potentially reducing necessity for lumpectomies and mastectomies, decrease radiation exposure, and enhance patient survival. ZetaPrime’s single-dose in-vivo study showed improved survival and tumor suppression over Tamoxifen and Verzenio in a mouse mammary fat pad model; results will be presented at the upcoming SABCS conference.

Continued Momentum

The Series B1 funding follows a series of strategic milestones for Zetagen, including:

• Expansion of the company’s global IP portfolio to 70+issued patents including Composition-of-Matter patents & claims on ZetaMet™, ZetaMast™, and ZetaPrime™
• Successful completion of the Phase 2a study of ZetaMet™ for metastatic breast cancer to bone
• Accepted abstracts by SABCS on ZetaMet™ preliminary clinical results and ZetaPrime™ in-vivo results of head-to-head comparison towards Verzenio

About Zetagen Therapeutics
Zetagen has three novel drugs in development with the Zeta Platform, ZetaMet™ (Zeta-BC-003), for the treatment of metastatic breast cancer to bone, ZetaMast™ (Zeta-MBC-005) for breast cancer liver metastases (BCLM), and ZetaPrime™ (Zeta-PBC-007) for the treatment of primary HR+ breast cancer, all with inspiring results. To learn more, visit www.zetagen.com. The entire Zeta platform is designed for intratumoral administration to reduce off-target toxicity, utilizing proprietary carriers—some incorporating our New Molecular Entity. The USPTO has granted Zetagen Composition-of-Matter patents and claims for all three therapeutics.

Zetagen Upcoming Events
Zetagen will attend & present at the 2025 San Antonio Breast Cancer Symposium (SABCS) and attend the 2026 JP Morgan Healthcare Conference.

Forward-Looking Statements
This press release contains certain forward-looking statements with the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 and Private Securities Litigation Reform Act, as amended, including those relating to the Company’s product development, clinical and regulatory timelines, market opportunity, competitive position, possible or assumed future results of operations, business strategies, potential growth opportunities and other statements that are predictive in nature. These forward-looking statements are based on current expectations, estimates, forecasts and projections about the industry and markets in which we operate and management’s current beliefs and assumptions.

Contacts

Investor Inquiries:
Zetagen Therapeutics, Inc.
Email: InvestorRelations@zetagen.com

Strategic Inquiries:
Joe C. Loy, CEO
Email: jloy@zetagen.com

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