Oncolytics Biotech® Inc. (NASDAQ: ONCY) (TSX: ONC) and SOLTI-Innovative Breast Cancer Research today announced the publication of an electronic poster with clinical data from the AWARE-1 window-of-opportunity breast cancer study at The Society for Immunotherapy of Cancer (SITC) 35th Anniversary Annual Meeting.

The AWARE-1 study, a collaboration between Oncolytics Biotech and SOLTI, combines the appropriate intervention for each patient's breast cancer sub-type, plus pelareorep, with or without atezolizumab (Tecentriq®), followed by surgery in early-stage breast cancer patients. Data presented in the electronic poster were from the ten HR+/HER2- breast cancer patients that make up the study's first cohort. These data demonstrate the ability of pelareorep to promote a pro-inflammatory tumor microenvironment (TME) and provide a basis for the findings of a prior successful phase 2 trial (IND-213) that showed a near doubling of overall survival with pelareorep treatment in HR+/HER2- breast cancer patients (link to PR, link to poster).

"AWARE-1's elegant paired-biopsy design allows us to assess the impact of pelareorep on each patient's tumor immune environment, and the results to date have been very promising," said Dr. Aleix Prat, M.D., PhD., Translational Investigator of the Study, SOLTI President and Head of the Medical Oncology Department at Hospital Clinic in Barcelona. "These data continue to support pelareorep's ability to train the immune system to target cancer and highlight its potential to address a critical unmet need by increasing the number of patients responding to checkpoint inhibitor therapies. Data presented at SITC showing pelareorep-induced generation and expansion of anti-tumor and anti-viral T cell clones are also noteworthy, as they suggest the induction of a durable anti-cancer immune memory effect. These data, together with previously reported AWARE-1 results, provide strong support for the observed survival benefit in a prior randomized phase 2 study evaluating pelareorep in metastatic breast cancer patients."

Key data and conclusions from the electronic poster include:

• Tumor-cell specific pelareorep replication was observed in all cohort-1 patients following systemic pelareorep administration
• 70% of cohort 1 patients saw an increase in CelTIL, the study's primary endpoint and a measure of tumor-associated cellularity and tumor-infiltrating lymphocytes that is associated with favorable clinical outcomes
• On average, there was a 14-fold increase in intratumoral CD8+ T cells from baseline (pre-pelareorep administration) to surgery (21-days post-administration), with increases observed in all cohort-1 patients
• Pelareorep administration led to the generation and expansion of new T cell clones in the tumor and periphery, which included both anti-tumor and anti-viral clones

Thomas Heineman, M.D., Ph.D., Global Head of Clinical Development and Operations at Oncolytics, commented, "These newly announced AWARE-1 results add to the promising clinical dataset supporting pelareorep's immunotherapeutic mechanism of action and to the proposed registration pathway in our lead metastatic breast cancer program. The observed 70% CelTIL response rate in cohort-1 patients is highly encouraging, as CelTIL is associated with favorable patient outcomes, and this response rate was achieved despite the absence of checkpoint blockade therapy. Further, previously announced data have shown that CelTIL scores correlate with high peripheral T cell clonality, underscoring T cell clonality's potential as a predictive biomarker that may facilitate the design of future registrational trials and improve their chances of success. We look forward to presenting additional AWARE-1 data later this year and to the continued progress of the trial, which will be key as we move our lead breast cancer program towards a registrational study."

The electronic poster, titled, "Changes in T cell clonality in AWARE-1 study, a window-of-opportunity study with atezolizumab and the oncolytic virus pelareorep in early breast cancer" is being presented at SITC by Dr. Prat. As of the SITC data cut-off, AWARE-1 has enrolled 23 out of 38 patients, including all patients in the study's first two cohorts.

Details on the AWARE-1 electronic poster, which are available on the SITC 2020 website and on the Posters & Publications page of Oncolytics' website (LINK), are shown below.

Poster Number: 806

Title: Changes in T cell clonality in AWARE-1 study, a window-of-opportunity study with atezolizumab and the oncolytic virus pelareorep in early breast cancer

Presentation Date and Time: Thursday, November 12 from 4:50-5:20 p.m. EST and Saturday, November 14 from 1:00-1:30 p.m. EST

Presenter: Dr. Aleix Prat