SAN FRANCISCO, CA – Feb. 24, 2026 – Siren Biotechnology announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to SRN-101, the company’s lead AAV-based immuno-gene therapy for recurrent high-grade glioma (HGG).
The designation is intended to expedite the development and review of therapies addressing serious conditions with significant unmet medical need. Siren recently received FDA clearance of its first Investigational New Drug (IND) application for SRN-101, enabling first-in-human clinical evaluation in patients with recurrent HGG.
SRN-101 is a recombinant adeno-associated virus (AAV) vector engineered to express an immunomodulatory cytokine designed to locally activate a potent anti-tumor immune response within the tumor microenvironment. The therapy is built on Siren’s Universal AAV Immuno-Gene Therapy platform, which aims to overcome limitations of conventional immunotherapies in solid tumors by enabling sustained, localized cytokine expression directly at the tumor site.
“Fast Track Designation underscores the urgency of bringing new therapeutic options to patients with recurrent high-grade glioma,” said Nicole K. Paulk, PhD, Founder, CEO, and President of Siren Biotechnology. She noted that SRN-101 represents a fundamentally new approach to treating solid tumors and reflects the FDA’s recognition of its potential clinical impact.
High-grade gliomas, including glioblastoma, are among the most aggressive and lethal primary brain tumors. Standard treatments such as surgery, radiation, and chemotherapy provide limited survival benefit, highlighting the need for innovative approaches such as AAV-mediated immuno-gene therapy.
The development of SRN-101 has been supported in part by funding from the California Institute for Regenerative Medicine (CIRM), a state agency dedicated to advancing regenerative medicine, stem cell, and gene therapy research.
