On July 8, 2025 Oncolytics Biotech Inc. (NASDAQ: ONCY) (TSX: ONC), a leading clinical-stage company specializing in immunotherapy for oncology, reported a strategic update highlighting its compelling clinical data from two tumor types and outlining a sharpened focus on advancing pelareorep, the Company’s intravenously delivered oncolytic virus immunotherapy, into registration-enabling studies (Press release, Oncolytics Biotech, JUL 8, 2025, View Source [SID1234654284]).

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"We are no longer in the business of funding proof-of-concept studies," said Jared Kelly, Chief Executive Officer of Oncolytics. "We have meaningful clinical data in hand—not just signals. The survival benefit across multiple tumor types demands a focused approach to take pelareorep directly into registration-enabling trials. We will use our fast-track status to find the most efficient regulatory path forward this summer to advance our platform in a product technology."

Results from two completed first-line metastatic pancreatic ductal adenocarcinoma (mPDAC) trials demonstrate a strong and consistent efficacy signal showing extremely rare 2-year overall survival rates of 21.9% vs. 9.2% based on pooled data from over 100 patients across two studies evaluating pelareorep combined with a chemotherapy backbone. In addition, a best-in-class 62% objective response rate (ORR) was observed in a single-arm study of pelareorep in combination with a chemotherapy backbone and a checkpoint inhibitor in 13 evaluable patients. These results collectively represent promising efficacy for a therapeutic regimen that includes an immunotherapy in this difficult-to-treat cancer. Currently, there are no approved immunotherapies for first-line treatment of mPDAC.

Clinical results of pelareorep in first-line mPDAC studies
Company
(Study)
Description
(Patients) 1-Year Survival 2-Year Survival Notes
Oncolytics
(REO 017)
Pelareorep+ Gemcitabine
(34 patients)
45% vs. 22% 24% vs. 4%
Disease Control Rate (DCR): 83% vs. 33%
Single arm vs. gemcitabine benchmark

Oncolytics
(NCI 8601)
Paclitaxel/Carboplatin + Pelareorep
(36 patients) vs.
Paclitaxel/Carboplatin
(37 patients)
34% vs. 28% 20% vs. 6%
Randomized study vs. control arm
(excluding crossover)
Oncolytics
(REO 029)
Pelareorep+ Gemcitabine/
Nab-Paclitaxel+ Atezolizumab
(13 patients)
45% vs. 35% N/A
ORR: 62% vs. 23%
Single arm vs. gemcitabine/
nab-paclitaxel benchmark

Pelareorep’s clinical activity in HR+/HER2- metastatic breast cancer – a large indication with continued significant unmet medical need and no currently approved immunotherapies – has been demonstrated in two randomized phase 2 studies, both of which showed a median overall survival (mOS) benefit of greater than 10 months compared to standard-of-care chemotherapy (IND.213 mOS: 21.0 vs. 10.8 months; BRACELET-1 mOS: not statistically reached; conservative estimate = 32.1 months vs. 18.2 months). In the randomized, controlled BRACELET-1 study, pelareorep combined with paclitaxel yielded a 12.1-month median progression-free survival (PFS) compared to 6.4 months in the paclitaxel alone control arm.

"Pelareorep represents a tipping point for immunotherapy in cold tumors," said Dr. Thomas Heineman, Chief Medical Officer of Oncolytics. "It is delivering consistent immunologic and clinical responses in multiple tumor types. Most impressively, pelareorep activates the immune system to produce clinical benefits in cancers that are typically unresponsive to immunotherapies like mPDAC and unresectable HR+/HER2- breast cancer, creating new oncology entry points for immune-based combination therapies."

Data from more than 1,100 patients enrolled in multiple studies across several tumor types affirm that pelareorep has a favorable, well-understood safety profile. The most common treatment-related adverse events (TRAEs) are "flu-like" symptoms, such as fever, chills, headache, fatigue, myalgia, cough, anorexia, nausea, diarrhea, or vomiting, and rarely resulted in clinically significant grade ≥3 TRAEs. Adverse events are typically transient and manageable with over-the-counter medications.

Pelareorep received Fast Track designations from the U.S. Food and Drug Administration (FDA) in 2017 for metastatic breast cancer and in 2022 for mPDAC in combination with chemotherapy and atezolizumab. In 2015, pelareorep also received Orphan Drug Designations from the FDA and European Medicines Agency (EMA) for the treatment of pancreatic cancer.

The Company released a new corporate presentation, available on its website, that provides detailed clinical and translational data.