One in eight women will face a breast cancer diagnosis in the U.S., with one in three of those cases becoming metastatic. When breast cancer metastasizes, it often spreads to the bones, lungs, or liver, eventually becoming resistant to endocrine-blocking therapies and recurring in approximately 50% of patients. The five-year survival rate for distant metastatic breast cancer is a mere 29%. These statistics highlight the critical need for innovative treatments to manage and extend survival for metastatic breast cancer patients.
The metastatic breast cancer treatment market is projected to grow at a compound annual growth rate (CAGR) of 10.4% from 2021 to 2030, reaching $41.74 billion. With no direct cure available, the focus remains on controlling the cancer and increasing survival rates. Enter Oncolytics Biotech Inc. (NASDAQ: ONCY), a clinical-stage biopharmaceutical company specializing in immunotherapeutics for oncology, which has shown promising results in early-phase clinical trials with its leading agent, pelareorep.
Pelareorep, an intravenously delivered immunotherapeutic agent, has demonstrated the potential to nearly double overall survival rates when added to standard metastatic breast cancer treatments in patients with HR+/HER2- breast cancer. It works by generating, recruiting, and training immune cells to recognize and kill cancer cells while remodeling the tumor microenvironment to allow immune cell access. This mechanism of action transforms “cold” tumors into “hot” ones, making them more responsive to treatment. When combined with existing regimens like chemotherapy, pelareorep extends survival times and expands T cell clones in the blood.
In the BRACELET-1 randomized Phase 2 trials, pelareorep showed meaningful improvements in overall response rate and progression-free survival. Data from these trials, along with the AWARE-1 studies, consistently indicate that pelareorep increases T cell clones and peripheral tumor-infiltrating lymphocyte counts, demonstrating a manageable safety profile. Positive results from the BRACELET-1 and IND-213 randomized trials revealed significant clinical improvements in the pelareorep/paclitaxel combination arms compared to paclitaxel monotherapy.
Oncolytics' commitment to advancing pelareorep is further evidenced by its recent interactions with the FDA. Pelareorep has received fast track designation, allowing for expedited review. Additionally, the FDA has supported progression-free survival as the primary endpoint for the planned potential registration-enabling trial for pelareorep in HR+/HER2- metastatic breast cancer patients. This trial will enroll patients for whom hormonal therapy has not worked and who have received no more than one line of antibody-drug conjugate (ADC) therapy.
“Aligning with the FDA on key design elements and objectives of our planned registrational trial for pelareorep marks a critical step towards bringing this innovative treatment to patients,” said Thomas Heineman, M.D., Ph.D., Chief Medical Officer at Oncolytics. He added that the de-risked program builds on compelling data and key learnings from BRACELET-1 and IND-213, which demonstrated clinically meaningful benefits in patients receiving pelareorep and paclitaxel compared to paclitaxel alone.
Breast cancer is a prevalent disease, and while many cases are treatable, metastatic breast cancer presents a significant challenge. At stage 4, the tumors have spread to other parts of the body, and recurrence is frequent. Extending survival rates is crucial, and Oncolytics believes pelareorep could be a key player in achieving this goal.
The ongoing and future clinical trials will be pivotal in determining pelareorep's efficacy and potential as a standard treatment for metastatic breast cancer, potentially changing the landscape of cancer treatment and offering new hope to patients worldwide.
