Promising findings from the BRACELET-1 trial fail to uplift investor confidence
On May 26th, Oncolytics Biotech Inc. (NASDAQ: ONCY) experienced a significant drop of -18.98% in its stock value, despite the company’s encouraging announcement regarding the positive results from the BRACELET-1 trial. This randomized phase 2 trial focused on evaluating treatment options for HR+/HER2- metastatic breast cancer patients.
The company revealed that the trial results were published in an abstract, which has been accepted for an oral presentation at the upcoming American Society of Clinical Oncology (ASCO) Annual Meeting, scheduled to take place from June 2 to 6, 2023, both in Chicago, Illinois, and online. The abstract can be accessed on the ASCO Annual Meeting website, providing detailed insights into the study.
BRACELET-1 enrolled a total of 48 patients who were randomized and evenly distributed across three cohorts. These cohorts evaluated different treatment combinations, including (1) paclitaxel monotherapy, (2) paclitaxel combined with pelareorep, and (3) paclitaxel plus pelareorep in combination with the anti-PD-L1 checkpoint inhibitor, avelumab (Bavencio®). All participants had previously experienced progression while on at least one hormone-based therapy with a CDK 4/6 inhibitor.
The trial’s primary endpoint, the overall response rate (ORR) at week 16, showed a remarkable improvement of ≥50% in the cohort treated with the combination of paclitaxel and pelareorep compared to the paclitaxel monotherapy cohort (31.3% vs. 20%) as of the ASCO abstract cut-off date in October 2022. In addition, this cohort reported a median progression-free survival (mPFS) of 9.6 months, surpassing the 6.4 months observed in the paclitaxel monotherapy cohort as of the same cut-off date.
Although overall survival data from the trial are still maturing, the results thus far validate the findings of IND-213, a previous phase 2 trial. IND-213 demonstrated a statistically significant near-doubling of median overall survival in HR+/HER2- metastatic breast cancer patients treated with the combination of pelareorep and paclitaxel (21.0 months, n = 28) compared to those receiving paclitaxel alone (10.8 months, n = 29).