Oncolytics Biotech (NASDAQ:ONCY)® Inc. (ONCY) today announced updated results from BRACELET-1, a randomized phase 2 trial in HR+/HER2- metastatic breast cancer, which include data featured in an oral presentation at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting, as well as additional new data and analyses.
BRACELET-1 enrolled 48 patients, including 45 that were randomized and well-balanced across three cohorts evaluating: (1) paclitaxel monotherapy; (2) paclitaxel in combination with pelareorep; and (3) paclitaxel plus pelareorep in combination with the anti-PD-L1 checkpoint inhibitor, avelumab (Bavencio®). A three-patient safety run-in was also conducted with patients receiving pelareorep, paclitaxel, and avelumab prior to randomization. All participants enrolled in the trial had previously progressed on at least one hormone-based therapy with a CDK 4/6 inhibitor. No patients in BRACELET-1 received chemotherapy for metastatic disease prior to enrolling in the trial.
Updated data from BRACELET-1 showed a median progression-free survival (mPFS) of 9.5 months in the paclitaxel plus pelareorep cohort vs. 6.3 months in the paclitaxel monotherapy cohort for a hazard ratio of 0.29 as of a
"BRACELET-1's positive results complement prior phase 2 data showing a statistically significant increase in overall survival when pelareorep was combined with paclitaxel by demonstrating similar robust improvements in PFS and ORR in less heavily pre-treated patients," said Dr.
A summary of response and PFS data from all 48 patients enrolled in BRACELET-1 is shown below.
Additional updated BRACELET-1 data 1:
Paclitaxel (PTX) Monotherapy (n=15) | PTX + Pelareorep (n=16) | PTX + Pelareorep + Avelumab (n=17)2 | |
Confirmed ORR Over Course of Trial | 2 (13.3 %) | 6 (37.5 %) | 3 (17.6 %) |
mPFS (months) | 6.3 (95% CI: 3.9, NR) | 9.5 (95% CI: 6.5, NR) | 6.2 (95% CI: 4.0, NR) |
PFS Hazard Ratio vs. PTX Monotherapy | - | 0.29 (95% CI: 0.09, 0.98) | 1.31 (95% CI: 0.47, 3.65) |
12-month PFS Rate (%) | 0 (95% CI: -, -) | 32.8 (95% CI: 11.7, 92.4) | 0 (95% CI: -, -) |
1. Data from a 2. Data include all patients enrolled in trial. Response data presented by Clark et al. at ASCO 2023 included the 45 randomized patients and excluded participants in the three-patient safety run-in in cohort 3. CI: Confidence interval; NR: Not reached. |
Key biomarker and safety findings from BRACELET-1 include:
- Association between T cell expansion and efficacy measures: A statistically significant increase in T cell fraction, a measure of T cell expansion, was observed in cohort 2 (paclitaxel + pelareorep) but not cohort 3 (paclitaxel + pelareorep + avelumab)
- Generally favorable and manageable safety profile: Pelareorep displayed a manageable safety profile consistent with what has been observed in prior clinical trials that have collectively treated over 1,100 patients
Dr.
A copy of slides from the ASCO oral presentation on BRACELET-1, titled 'BRACELET-1 (PrE0113): Inducing an Inflammatory Phenotype in Metastatic HR+/HER2- Breast Cancer with the Oncolytic Reovirus Pelareorep in Combination with Paclitaxel and Avelumab,' is available on the Posters & Publications page of Oncolytics' website (LINK). Additional data and analyses from BRACELET-1 beyond those reported at the ASCO Annual Meeting will be available in the most recent investor presentation available by clicking here. Details of the key opinion leader webinar are shown below.
Key Opinion Leader Webinar
Oncolytics will host a key opinion leader (KOL) webinar featuring