FDA Greenlights Siren Biotechnology’s Groundbreaking AAV Gene Therapy for Brain Cancer

SAN FRANCISCO, CA –  January 28, 2026- Siren Biotechnology, a leader in the field of Universal AAV Immuno-Gene Therapy, has reached a historic regulatory milestone. The U.S. Food and Drug Administration (FDA) has officially cleared the company’s first Investigational New Drug (IND) application, a move that transitions Siren into a clinical-stage biotechnology firm. This clearance paves the way for the initiation of a first-in-human clinical trial designed to evaluate their lead AAV-based investigational program in adult patients suffering from recurrent high-grade glioma.

This development is particularly significant as it is believed to be the first FDA-cleared IND for an adeno-associated virus (AAV) therapy within an oncology indication. While AAV vectors have traditionally been utilized for rare genetic disorders, Siren’s AAV platform leverages the virus’s delivery precision to transport immune-modulating payloads directly into tumors. This AAV-driven approach aims to create a localized and durable immune response, transforming how clinicians treat aggressive “cold” tumors that typically evade the immune system.

Nicole K. Paulk, PhD, the Founder, CEO, and President of Siren Biotechnology—and a recognized expert in AAV engineering—hailed the clearance as a defining moment for the company. She noted that the milestone is the culmination of years of focused AAV platform development and rigorous translational work. By utilizing AAV vectors to turn tumors into “biorefining factories,” the company hopes to overcome the limitations of systemic therapies. This advancement builds on the broader Universal AAV Immuno-Gene Therapy platform, which was designed specifically for the complexities of high-grade gliomas.

The path to this clinical trial was supported by the FDA’s prior granting of Orphan Drug and Rare Pediatric Disease designations for the AAV program. Furthermore, the research and the scaling of AAV manufacturing activities were made possible through significant funding from the California Institute for Regenerative Medicine (CIRM). As Siren prepares to dose its first patients, the biotech community is watching closely to see if this AAV-based immunotherapy can provide a much-needed breakthrough for patients facing lethal brain tumors with limited treatment options.