Pelareorep Plus Atezolizumab Generates Durable Responses in Previously Treated SCAC

Pelareorep plus atezolizumab (Tecentriq) produced durable responses in patients with second-line or later squamous cell anal cancer (SCAC), according to updated data from cohort 4 of the phase 1/2 GOBLET trial (NCT07280377).¹

Findings showed that evaluable patients experienced a median duration of response (DOR) of approximately 15 months, and the median overall survival (OS) had not yet been reached. All patients who responded to treatment survived beyond 12 months, including multiple patients who survived for more than 24 months.

Oncolytics Biotech noted that the DOR estimate was derived from internal calculations, and it compared favorably with the 9.5-month median DOR reported with retifanlimab-dlwr (Zynyz) monotherapy in a similar population in the phase 2 POD1UM-202 trial (NCT03597295); the 2 results were not derived from a head-to-head comparison.¹

In earlier cohort 4 data reported in January 2026, the combination elicited an objective response rate (ORR) of approximately 29% among evaluable patients with third-line metastatic SCAC (n = 14), including 2 complete responses and 2 partial responses, with a median DOR of approximately 17 months at that time.²

"We see anal cancer as the starting point for building a pelareorep plus checkpoint inhibitor platform across HPV-driven cancers. Our survival data and recent FDA regulatory clarity give us a path to pursue registration in anal cancer while expanding into other HPV-associated tumors, including head and neck cancer, where pelareorep has already demonstrated encouraging clinical activity," Jared Kelly, chief executive officer of Oncolytics Biotech, stated in a news release.¹

Pelareorep, an intravenously delivered immunotherapeutic agent, has received FDA fast track designation in SCAC. Following recent FDA interactions, the company plans to explore additional clinical studies with a potential checkpoint inhibitor partner to support registrational development in SCAC. Oncolytics stated that durable responses may support an accelerated approval pathway and that OS could provide evidence of clinical benefit to support full approval, subject to FDA agreement. The company may also explore initiating a combination study in HPV-associated head and neck cancer in the near term.

How was pelareorep plus atezolizumab evaluated in cohort 4 of GOBLET?

GOBLET is an open-label, multiple-indication, phase 1/2 platform study evaluating pelareorep-based combinations in patients with advanced or metastatic gastrointestinal cancers at 17 centers in Germany.^1,3 Cohorts 1 through 4 are nonrandomized, whereas patients in cohort 5 are randomly assigned 1:1 to 2 treatment arms; the trial has an estimated enrollment of 122 patients.³

Cohort 4 enrolled patients with second-line or later, locally advanced or metastatic, unresectable SCAC of viral or nonviral origin who received prior chemotherapy. Across cohorts, key eligibility criteria include an ECOG performance status of 0 or 1, measurable disease per RECIST 1.1 criteria, and adequate hematologic, renal, and hepatic function. Patients who previously received an immune checkpoint inhibitor, as well as those with symptomatic brain metastases or autoimmune disease requiring systemic treatment within the past 2 years, were excluded; cohort 4 also excluded patients with HIV infection and a CD4-positive T-cell count below 300 cells/µL.

In cohort 4, patients received pelareorep at 4.5 × 10¹⁰ TCID50 as a 1-hour intravenous infusion plus atezolizumab at 840 mg intravenously.

The primary end point for cohort 4 was ORR at week 16 per RECIST 1.1 criteria, as assessed by investigators and/or central review. Under a Simon 2-stage design, cohort 4 could expand to up to 28 patients. Secondary end points include progression-free survival, DOR, disease control rate, ORR, and OS.

References

1. Oncolytics Biotech reports strong durability and survival data in anal cancer, positioning pelareorep as potential backbone immunotherapy across HPV-driven cancers. News release. Oncolytics Biotech. October 27, 2026. Accessed October 27, 2026. https://ir.oncolyticsbiotech.com/press_releases/oncolytics-biotech-reports-strong-durability-and-survival-data-in-anal-cancer-positioning-pelareorep-as-potential-backbone-immunotherapy-across-hpv-driven-cancers/
2. Oncolytics Biotech announces updated clinical data from GOBLET cohort 4 demonstrating activity of pelareorep plus atezolizumab in third-line anal cancer. News release. Oncolytics Biotech. January 12, 2026. Accessed October 27, 2026. https://ir.oncolyticsbiotech.com/press_releases/oncolytics-biotech-announces-updated-clinical-data-from-goblet-cohort-4-demonstrating-activity-of-pelareorep-plus-atezolizumab-in-third-line-anal-cancer/
3. A study in advanced or metastatic gastrointestinal cancers exploring treatment combinations with pelareorep and atezolizumab. ClinicalTrials.gov. Updated May 19, 2026. Accessed October 27, 2026. https://clinicaltrials.gov/study/NCT07280377