Oncolytics Biotech and SOLTI Present Further Positive Pelareorep Translational Data at SITC - Seite 2

Summary of Data and Findings for Expanded Translational Analysis of the AWARE-1 Study:

Samples: From the AWARE-1 window-of-opportunity study of patients with early-stage HR+/HER2- breast cancer:

• Collected from cohort 2 patients who received pelareorep plus letrozole and atezolizumab (n=10)
• Tumor biopsies were collected on Day 1 (pretreatment), Day 3 (prior to atezolizumab) and Day 21 (when tumors were surgically removed)

Evaluation process:

• Samples were evaluated using a biomarker panel of 37 conjugated antibodies that bind to tumor antigens and immune cells
• The novel IMC technology was used to visualize cellular interactions down to the single cell level

Results: Visualization of the data shows that pelareorep treatment changed the number of PD-L1 tumor cells and the architecture of the tumor microenvironment:

• By Day 3, an increase in PD-L1 positivity and cytotoxic T cells could be seen at a higher rate of tumor infiltration relative to baseline.

About AWARE-1

AWARE-1 was an open-label window-of-opportunity study in early-stage breast cancer. The study combined pelareorep, without or with atezolizumab, and the standard of care therapy according to breast cancer subtype. Tumor tissue was collected from patients as part of their initial breast cancer diagnosis, again on day three following initial treatment, and finally at three weeks following treatment, on the day their tumor is surgically resected. Key objectives of the study were to confirm that pelareorep is acting as a novel immunotherapy, to evaluate potential synergy between pelareorep and checkpoint blockade, and to collect biomarker data. The primary endpoint of the translational study was overall CelTIL score (a measurement of cellularity and tumor-infiltrating lymphocytes). Secondary endpoints for the study included safety and tumor and blood-based biomarkers. AWARE-1 met its primary endpoint of overall CelTIL score in 2021 (link to the PR, link to the poster). Additional biomarker data announced in 2022 showed pelareorep's potential to improve the prognosis of breast cancer patients (link to the PR, link to the poster).