Using Viruses to Fight Cancer: A New Approach to Treating Solid TumorsMarch 1, 2022
Today, more people are surviving cancer than ever before, thanks to advances in diagnosis and treatment. Now, a new treatment technology being developed – oncolytic virus therapy – may lend hope for patients battling locally advanced or metastatic solid tumors.
Killing Cancer Cells with Engineered Viruses
Oncolytic virus therapies are immunotherapies that use engineered viruses to selectively infect and destroy cancer cells (stimulating the release of cancer antigens) and to activate an immune response that can potentially eradicate additional tumor cells nearby and possibly elsewhere in the body.
These genetically engineered viruses are especially promising due to their improved ability to more selectively kill cancer cells while leaving non-cancer cells intact, compared to current therapeutic options, and for their ability to be used in combination with immune checkpoint inhibitors. There is only one oncolytic virus therapy currently available, approved by the U.S. FDA for the treatment of melanoma in 2015.
A Partnership, Then an Acquisition
One of the oncolytic virus therapies Pfizer is currently studying in patients is PF-07263689, a product that arose from its partnership with and subsequent acquisition of IGNITE Immunotherapy.
Pfizer initially acquired a 50 percent equity interest in IGNITE in 2016, and in 2019 exercised its option to acquire the remaining 50 percent.
Pfizer was driven to partner with and eventually acquire IGNITE because of the oncolytic virus expertise of its founders, the promise of the company’s original directed evolution technology platform for oncolytic viruses, and the scientific proof-of-concept for the IGNITE lead product design that led to PF-07263689.
Also key was IGNITE’s emphasis on delivering a first-in-class, novel, and diverse library of vaccina-based viruses with desired properties that could be used to design and develop novel oncolytic viruses with systemic bioavailability and enhanced tumor specificity. IGNITE’s capabilities not only complemented Pfizer’s immuno-oncology portfolio, but have allowed Pfizer to be at the forefront of this revolutionary technology.
“IGNITE has been dedicated to unlocking the full potential of oncolytic virus cancer immunotherapy through transformative innovation and product design, focusing on efficient intravenous delivery to tumors, multi-mechanistic efficacy, and patient safety,” said David Kirn, M.D., co-founder, former CEO and Chairman of IGNITE.
First Patient Enrolled in Clinical Study
Recently, the first patient was enrolled in Pfizer’s Phase 1 clinical study to better understand the effects of this potential therapy both by itself and in combination with sasanlimab (an investigational anti-programmed cell death protein 1 [PD-1] antibody) – as a third line or later treatment in patients with selected locally advanced or metastatic solid tumors, who have exhausted all available standard of care therapies available to them. If successful in clinical studies and eventually approved, this oncolytic virus therapy could provide patients who have limited or no treatment options left with a promising new choice.
“We’re thrilled to have begun this trial and look forward to continuing to investigate the ability of oncolytic virus therapies to help patients living with cancer,” said Jeff Settleman, Ph.D., Senior Vice President and Chief Scientific Officer, Oncology Research and Development, Pfizer. “Pfizer’s exploration of this potential new treatment paradigm reflects our commitment to immuno-oncology and to meeting the needs of patients who stand to benefit from diverse treatment options.”
 McKinney, R. More people are surviving cancer. What’s next? Association of American Medical Colleges. February 2020. Available here.
 National Cancer Institute “Oncolytic Virus Therapy: Using Tumor-Targeting Viruses to Treat Cancer.” February 2018. Available here.
 National Cancer Institute “FDA Approves Talimogene Laherparepvec to Treat Metastatic Melanoma.” November 2015. Available here.