Oncolytics Biotech Inc. and SOLTI-Innovative Cancer Research announced new clinical biomarker data demonstrating pelareorep's immunotherapeutic effects, synergy with checkpoint inhibition, and potential to improve the outlook for patients with HR+/HER2- breast cancer. The data, which are featured in a poster presentation at the 2022 European Society for Medical Oncology (ESMO) Breast Cancer Meeting, are from cohorts 1 and 2 of the AWARE-1 window-of-opportunity study in early-stage breast cancer patients. Patients in AWARE-1's first two cohorts were treated with pelareorep and the aromatase inhibitor letrozole without (cohort 1), or with (cohort 2), the PD-L1 checkpoint inhibitor atezolizumab approximately 21 days prior to the surgical resection of their tumors.

Cohorts 1 and 2 of AWARE-1 exclusively enrolled patients with HR+/HER2- disease, the breast cancer subtype that Oncolytics intends to examine in a future registrational study. Previously reported results showed AWARE-1 met its primary translational endpoint, with cohort 2 achieving the pre-specified success criteria for treatment-induced increases in CelTIL score (link to the PR). CelTIL score is a metric for tumor inflammation and cellularity and is associated with improved clinical outcomes in breast cancer patients.

Key data and conclusions from the ESMO Breast Cancer poster include: Gene expression analyses showed 100% of evaluable patients had a Risk of Recurrence Score (ROR-S) classified as "low" at surgery vs. 55% with a "low" ROR-S at baseline (information pertaining to prognostic testing of gene signature assays in breast cancer can be found by clicking here) - Treatment with pelareorep with (cohort 2) or without (cohort1) atezolizumab led to the conversion of tumors from the more aggressive luminal B to the luminal A subtype, which is associated with improved clinical outcomes- 100% of evaluable cohort 2 tumors were luminal A at surgery (21 days post-treatment) vs. 70% at baseline (pre-treatment) -70% of evaluable cohort 1 patients had luminal A tumors at surgery vs.

40% at baseline Pooled analysis of tumors from cohorts 1 and 2 shows a statistically significant 4-fold post-treatment increase in the average expression of caspase 3, which is a marker of apoptotic cell death- Pooled analysis across cohorts 1 and 2 shows statistically significant increases in markers of T cell activation and no significant changes in markers of T cell exhaustion from baseline to surgery - BRACELET-1 is a randomized phase 2 trial in HR+/HER2- metastatic breast cancer. The trial includes cohorts evaluating paclitaxel monotherapy, paclitaxel plus pelareorep, and paclitaxel plus pelareorep in combination with a checkpoint inhibitor. Top-line data from the trial are expected in fourth quarter of 2022.