Indianapolis, Indiana, U.S., October 5, 2026
Genezen and InterAct Therapeutics have announced a strategic manufacturing partnership to advance the clinical development of IAT-S2, an investigational AAV8-based gene therapy being developed for liver-dominant metastatic breast cancer. The program is focused on breast cancer liver metastases (BCLM), a serious complication of advanced breast cancer for which there are currently no therapies specifically approved to target the tumor-liver microenvironment. Under the partnership, Genezen will provide AAV process development, manufacturing scale-up, and GMP manufacturing expertise to support InterAct Therapeutics as it progresses through IND-enabling studies and toward a planned Phase 1 clinical trial.
IAT-S2 Targets the Liver Tumor Microenvironment
InterAct Therapeutics is developing IAT-S2 as a one-time, disease-modifying gene therapy designed to modify the biological environment in the liver where metastatic breast cancer cells establish and grow. The program originated from research led by Isaac Chan, MD, PhD, at UT Southwestern Medical Center, investigating interactions between metastatic breast cancer cells and healthy liver cells. Rather than targeting cancer cells alone, the company’s approach seeks to alter the metastatic microenvironment to suppress metastatic growth. Liver metastases are common in advanced breast cancer and are associated with poor outcomes, making new approaches to controlling metastatic disease an important area of therapeutic research. InterAct selected AAV8 as the delivery vector in part because of its ability to efficiently target hepatocytes, supporting a liver-directed strategy. In preclinical studies, the company reported near elimination of liver metastases across five mouse models of liver metastasis.
Genezen to Support IND-Enabling Manufacturing
Following positive FDA INTERACT feedback, InterAct Therapeutics is preparing for IND-enabling studies with manufacturing support from Genezen’s viral vector development team in Indianapolis. Genezen will contribute its platform AAV process development, scale-up, and GMP manufacturing capabilities to support toxicology studies and production of clinical-grade material required for future human studies. The partnership is intended to help InterAct advance IAT-S2 toward an Investigational New Drug (IND) submission and eventual first-in-human clinical development. Manufacturing is an important component of the development pathway for viral-vector gene therapies, as reproducible processes and appropriate GMP controls are required to generate clinical material for regulatory and clinical programs. Genezen’s experience in AAV development and manufacturing is intended to support the program as it moves from preclinical research toward clinical-stage development.
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Partnership Advances Liver-Directed Gene Therapy
The collaboration combines InterAct Therapeutics’ metastatic disease platform with Genezen’s specialized gene therapy manufacturing capabilities. InterAct selected Genezen after evaluating potential manufacturing partners, citing its experience with AAV development, reliability, and ability to support the program’s development timeline. Genezen has more than 12 years of experience in gene therapy and operates viral-vector manufacturing facilities designed to support programs from early development through commercial-scale production. The company also has experience manufacturing a commercially approved AAV gene therapy. For InterAct, the partnership represents an important step in translating laboratory research into a potential therapeutic approach for patients with liver-dominant metastatic breast cancer. As the program advances through IND-enabling toxicology and manufacturing activities, the companies will work toward generating the data and clinical material needed for regulatory submission and Phase 1 evaluation. IAT-S2 remains an investigational therapy and will require successful completion of preclinical, regulatory, and clinical development before its safety and efficacy can be established in patients.
Source: Genezen, InterAct Therapeutics press release
