Jeong Heo^1,17, Tony Reid^2,17, Leyo Ruo³, Caroline J Breitbach⁴, Steven Rose², Mark Bloomston⁵, Mong Cho¹, Ho Yeong Lim⁶, Hyun Cheol Chung⁷, Chang Won Kim¹, James Burke⁴, Riccardo Lencioni⁸, Theresa Hickman⁴, Anne Moon⁴, Yeon Sook Lee⁹, Mi Kyeong Kim⁹, Manijeh Daneshmand¹⁰, Kara Dubois⁴, Lara Longpre⁴, Minhtran Ngo^11,12, Cliona Rooney^11.13, John C Bell^4,10, Byung-Geon Rhee¹⁴, Richard Patt¹⁵, Tae-Ho Hwang^9,16,18,* & David H Kirn^4,18,*

¹Department of Internal Medicine, Pusan National University and Medical Research Institute, Pusan National University Hospital, Seo-Gu, Busan, South Korea. ²Moores Cancer Center, University of California San Diego (UCSD), La Jolla, California, USA. ³Department of Surgery, McMaster University Medical Centre, Hamilton, Ontario, Canada. ⁴Jennerex Inc., San Francisco, California, USA. ⁵Department of Surgery, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA. ⁶Department of Medicine, Division of Hematology-Oncology, Samsung Medical Center, Ilwon-Dong, Gang Nam-Gu, Seoul, South Korea. ⁷Yonsei Cancer Center, Yonsei University College of Medicine, Seodaemun-gu, Yongdong Severance Hospital, Seoul, South Korea. ⁸Division of Diagnostic Imaging and Intervention, Pisa University School of Medicine, Lungarno Pacinotti, Pisa, Italy. ⁹SillaJen Inc., GeumJung-Gu, Busan, South Korea. ¹⁰Centre for Innovative Cancer Therapeutics, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada. ¹¹Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas, USA. ¹²Baylor College of Medicine, Houston, Texas, USA. ¹³Texas Children’s Hospital, Houston, Texas, USA. ¹⁴Green Cross Corporation, Giheung-gu, Yongin, South Korea. ¹⁵RadMD, Doylestown, Pennsylvania, USA. ¹⁶Department of Pharmacology, Pusan National University, Busan, South Korea. ¹⁷These authors contributed equally to this work. ¹⁸These authors jointly directed this work.

^*Correspondence to:  David H Kirn or Tae-Ho Hwang

Oncolytic viruses and active immunotherapeutics have complementary mechanisms of action (MOA) that are both self amplifying in tumors, yet the impact of dose on subject outcome is unclear. JX-594 (Pexa-Vec) is an oncolytic and immunotherapeutic vaccinia virus. To determine the optimal JX-594 dose in subjects with advanced hepatocellular carcinoma (HCC), we conducted a randomized phase 2 dose-finding trial (n = 30). Radiologists infused low- or high-dose JX-594 into liver tumors (days 1, 15 and 29); infusions resulted in acute detectable intravascular JX-594 genomes. Objective intrahepatic Modified Response Evaluation Criteria in Solid Tumors (mRECIST) (15%) and Choi (62%) response rates and intrahepatic disease control (50%) were equivalent in injected and distant noninjected tumors at both doses. JX-594 replication and granulocyte-macrophage colony-stimulating factor (GM-CSF) expression preceded the induction of anticancer immunity. In contrast to tumor response rate and immune endpoints, subject survival duration was significantly related to dose (median survival of 14.1 months compared to 6.7 months on the high and low dose, respectively; hazard ratio 0.39; P = 0.020). JX-594 demonstrated oncolytic and immunotherapy MOA, tumor responses and dose-related survival in individuals with HCC.