The landscape of cancer immunotherapy is witnessing a significant shift as pharmaceutical companies increasingly turn their attention to oncolytic viruses, highlighted by Merck & Co's recent $394 million acquisition of Viralytics. This strategic move signals growing confidence in viral therapies as potential enhancers for cancer treatment, particularly in combination with checkpoint inhibitors.
Current State of Oncolytic Virus Therapy
While Amgen's Imlygic (talimogene laherparepvec) remains the only approved oncolytic virus treatment since its 2015 launch, the field is rapidly expanding. Currently, 10 oncolytic viruses are undergoing clinical trials, with an additional 40 in laboratory development. These therapeutic agents work by introducing genetic material into cancer cells, modifying them to become visible to the immune system, which then targets and destroys the tumor.
Combination Therapy Potential
The limited success of Imlygic as a monotherapy has led researchers to explore combination approaches, particularly with checkpoint inhibitors. Current checkpoint inhibitor therapies show response rates as low as 20% in some cancers, creating a significant opportunity for complementary treatments. Oncolytic viruses could potentially serve as tumor 'primers,' enhancing the effectiveness of immunotherapy treatments.
Industry Movement and Strategic Partnerships
The sector has seen increased activity beyond Merck's Viralytics acquisition. Bristol-Myers Squibb made a significant move by securing rights to an "armed virus" from UK biotech PsiOxus Therapeutics in a deal potentially worth $900 million. Meanwhile, Targovax has emerged as one of the most advanced independent biotechs in the field.
Targovax's Strategic Position
Magnus Jaderberg, Targovax's chief medical officer, views the Viralytics acquisition as a positive industry signal. The company is advancing two key programs:
- TG01: A RAS neoantigen vaccine targeting resected pancreatic cancer, with potential applications in 30% of all cancers expressing the RAS biomarker
- ONCOS-102: An adenovirus platform in phase 1b/2 trials for mesothelioma, with additional development programs in ovarian and colorectal cancer
The company has established a partnership with AstraZeneca's MedImmune and is actively seeking additional collaborations with checkpoint inhibitor manufacturers. Erik Digman Wiklund, Targovax's CFO, acknowledges the challenges facing small biotechs in conducting phase 3 programs, indicating openness to licensing opportunities while remaining cautious about acquisition prospects.
Market Outlook
Industry experts anticipate increased interest from major pharmaceutical companies, including Roche and Genentech, who have yet to establish a presence in oncolytic virus technology. The field represents a promising frontier in cancer treatment, particularly as companies seek to enhance the effectiveness of existing immunotherapy approaches.
