Pembrolizumab in combination with the oncolytic virus pelareorep and chemotherapy in patients with advanced pancreatic adenocarcinoma: A phase Ib study a C

Devalingam Mahalingam*, Grey A. Wilkinson, Kevin H. Eng, Paul Fields, Patrick Raber, Jennifer L. Moseley, Karol Cheetham, Matt Coffey, Gerard Nuovo, Pawel Kalinski, Bin Zhang, Sukeshi Patel Arora, Christos Fountzilas

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Purpose: Pelareorep is an intravenously delivered oncolytic reovirus that can induce a T-cell–inflamed phenotype in pancreatic ductal adenocarcinoma (PDAC). Tumor tissues from patients treated with pelareorep have shown reovirus replication, T-cell infiltration, and upregulation of PD-L1. We hypothesized that pelareorep in combination with pembrolizumab and chemotherapy in patients with PDAC would be safe and effective. Patients and Methods: A phase Ib single-arm study enrolled patients with PDAC who progressed after first-line treatment. Patients received pelareorep, pembrolizumab, and either 5-fluoro-uracil, gemcitabine, or irinotecan until disease progression or unacceptable toxicity. Study objectives included safety and dose-limiting toxicities, tumor response, evaluation for reovirus replication, and immune analysis in peripheral blood and tumor biopsies. Results: Eleven patients were enrolled. Disease control was achieved in three of the 10 efficacy-evaluable patients. One patient achieved partial response for 17.4 months. Two additional patients achieved stable disease, lasting 9 and 4 months, respectively. Treatment was well tolerated, with mostly grade 1 or 2 treatment-related adverse events, including flu-like symptoms. Viral replication was observed in on-treatment tumor biopsies. T-cell receptor sequencing from peripheral blood revealed the creation of new T-cell clones during treatment. High peripheral clonality and changes in the expression of immune genes were observed in patients with clinical benefit. Conclusions: Pelareorep and pembrolizumab added to chemotherapy did not add significant toxicity and showed encouraging efficacy. Further evaluation of pelareorep and anti–PD-1 therapy is ongoing in follow-up studies. This research highlights the potential utility of several pretreatment and on-treatment biomarkers for pelareorep therapy warranting further investigation.

Original languageEnglish (US)
Pages (from-to)71-81
Number of pages11
JournalClinical Cancer Research
Issue number1
StatePublished - Jan 1 2020

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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