Oncolytics Biotech Announces New Translational Data From An Ongoing Study Showing Pelareorep’s Ability To Increase HPV-16-Specific T Cell Clones And Tumor-Infiltrating Lymphocyte Clones In Second-Line Or Later Squamous Cell Anal Cancer Patients; Immune Activation Levels More Than Doubled In Nearly All Patients After One Cycle Of Treatment; Substantial Increases In HPV-16-Specific T Cells And Tumor-Infiltrating Lymphocytes Observed When Pelareorep Is Combined With A Checkpoint Inhibitor

Oncolytics Biotech® Inc. (NASDAQ:ONCY) ("Oncolytics" or the "Company"), a clinical-stage immunotherapy company developing pelareorep, today announced new translational data from an ongoing study showing pelareorep’s ability to increase human papillomavirus ("HPV")-16-specific T cell clones and tumor-infiltrating lymphocyte ("TIL") clones in second-line or later squamous cell anal cancer ("SCAC") patients at the Society for Immunotherapy of Cancer ("SITC") 2026 Annual Meeting.

Pelareorep combined with a checkpoint inhibitor generated promising efficacy signals in second-line or later SCAC, including more than doubling the objective response rate and increasing median duration of response by 50% compared to the current approved therapy in that patient population. Multiple analyses help explain how pelareorep generates innate and adaptive immune responses and synergizes with other therapies. Highlights from the SITC abstract include:

In seven of eight evaluable patients, greater than two-fold increases in levels of the immune-activation biomarkers CXCL10, IFN-γ, and soluble PD-L1 were observed after one cycle of therapy.
After three cycles of treatment, all four evaluable patients saw expansion of TIL clones in peripheral blood, which was associated with reductions in tumor size, including two complete responses and two partial responses.
The four responding patients with TIL expansion also demonstrated significant expansion of at least one HPV-16-specific T cell clone.
Among 14 patients evaluated for HPV-16-specific immune responses, six showed HPV-16 clonal expansion, and four of those patients experienced tumor shrinkage.
The Phase 1/2, Simon 2-stage study is assessing the safety and efficacy of pelareorep in combination with a checkpoint inhibitor in second-line or later unresectable SCAC patients.

"These data reinforce pelareorep’s potential in multiple HPV-driven cancers as those tumor types generally exhibit low response rates to checkpoint inhibitors," said Thomas Heineman, MD, PhD, Chief Medical Officer of Oncolytics. "Pelareorep’s ability to increase tumor-infiltrating lymphocyte populations and expand HPV-specific T cells form the basis for its synergy with checkpoint inhibitors and reinforces the potential of this combination to combat tumor growth in HPV-associated cancers. More broadly, these data support our belief in pelareorep as a backbone immunotherapy capable of activating anti-tumor immunity and improving responses to multiple therapies across a wide range of tumor types."

"We see HPV-associated cancers as a compelling business development opportunity for pelareorep, spanning anal, HPV-positive oropharyngeal, cervical, and other malignancies and representing a potential $3 to 5 billion market based on our internal estimates," said Jared Kelly, Chief Executive Officer of Oncolytics. "The combination of HPV-specific T cell expansion in our anal cancer study and prior clinical efficacy signals in head and neck cancer gives prospective partners a differentiated scientific and clinical rationale to explore pelareorep alongside checkpoint inhibitors. With systemic delivery, substantial clinical experience, and the potential to pursue multiple indications, we believe pelareorep offers a scalable opportunity to extend immunotherapy franchises into underserved patient populations. Our priority is to translate this evidence into strategic collaborations that can accelerate development and realize the broader commercial opportunity."