Neoadjuvant Intravenous Oncolytic Vaccinia Virus Therapy Promotes Anticancer Immunity in Patients

Area of Science:

• Oncology
• Immunotherapy
• Virology

Background:

• Improving cure rates for surgically treated metastatic cancer is a research priority.
• Pexa-Vec (Pexastimogene Devacirepvec) is an immunotherapeutic oncolytic virus in late-stage clinical trials.

Purpose of the Study:

• To evaluate the safety and immunogenicity of presurgical intravenous Pexa-Vec administration.
• To assess Pexa-Vec distribution and biological effects in patients undergoing metastasis resection.

Main Methods:

• A single-center, nonrandomized study involving 9 patients with colorectal cancer liver metastases or metastatic melanoma.
• Patients received a single intravenous infusion of Pexa-Vec before planned surgical resection.
• Analysis included assessment of side effects, viral distribution, and immune responses.

Main Results:

• Pexa-Vec was detected in most resected tumors.
• Therapy induced IFNα secretion, chemokine induction, and both innate and adaptive anticancer immunity.
• Grade 3/4 side effects included lymphopenia and neutropenia; Pexa-Vec was found in plasma, not PBMCs.

Conclusions:

• Presurgical Pexa-Vec administration is feasible and stimulates anticancer immunity.
• This strategy shows promise for enhancing cancer cure rates in combination with surgery.
• Further development of presurgical oncolytic vaccinia virus-based therapies is supported.