From April 25 to April 30, 2025, U.S. time, ImmVira presented the Phase I clinical results of its oncolytic Herpes Simplex Virus ("oHSV") product MVR-C5252 targeting malignant glioma through poster presentation at American Association for Cancer Research ("AACR") annual meeting.

According to industry data, malignant glioma, a highly aggressive and recurrent brain cancer, has a five-year survival rate of less than 5%. Developed on ImmVira's proprietary OVPENS platform, MVR-C5252 is specifically engineered with designed attenuation to achieve on-target malignant gliocyte killing and armed with PD-1 antibody and IL-12, for the synergistic anti-tumor effects of "oncolysis + immune activation". This innovative product has obtained Investigational New Drug approval in both the U.S. and China, as well as Orphan Drug Designation from the FDA.

The Phase I trial, for which the clinical study results were released, was conducted in collaboration with Duke University, a renowned institution with expertise in oncolytic virotherapy, immunotherapy, and CNS treatments. Unlike the commonly used Ommaya reservoir, MVR-C5252 is delivered intracranially via convection-enhanced delivery ("CED"). This approach can provide slow and sustained positive pressure to the target brain area via an implanted catheter to ensure even drug distribution, enabling multiple dosing while bypassing the blood-brain barrier. To date, five patients with recurrent high-grade glioma have received MVR-C5252 treatments.

In Stage 1A of the study, three patients received 5×10⁶ PFU and completed the dose-limiting toxicity ("DLT") period. Serial cytokine analysis of cerebrospinal fluid ("CSF") showed dynamic immune responses and intended biologic activity, with measurable changes in cytokine concentrations post-infusion. In addition, no serious adverse events ("SAEs"), DLTs, or Grade 3–5 adverse events ("AEs") occurred. The only reported Grade 1–2 AEs included fatigue, flu-like symptoms, and cognitive disturbance, indicating a favorable safety profile of MVR-C5252 delivered via CED.

Dr. Grace Guoying Zhou, ImmVira's Chairwoman and CEO, said, "We are committed to developing advanced therapies featuring novel modalities using oHSV and engineered exosomes, to address complex and challenging diseases. After years of parallel development and in-depth explorations in both the U.S. and China, we have strategically focused on malignant glioma for the development of MVR-C5252, leveraging HSV-1's unique biological and translational medical characteristics and in line with highly unmet medical needs and substantial market potential. Our collaboration with Duke University, a global leader in glioma research and treatment, will accelerate clinical development of this innovative therapy, delivering a new solution for this type of severe life-threatening diseases."