SillaJen reports initiation of multinational randomized Phase 3 study of Pexa-Vec in HCC patients

SillaJen, Inc., a private, clinical-stage, biotherapeutics company focused on the development of oncolytic immunotherapy products for cancer, has announced the initiation of a multinational randomized Phase 3 open-label study of its lead product candidate, Pexa-Vec (formerly JX-594), in patients with advanced liver cancer, also known as hepatocellular carcinoma (HCC). The trial is evaluating the use of Pexa-Vec to treat HCC patients who have failed locoregional therapies and are eligible for treatment with sorafenib (Nexavar^®), the only approved drug for advanced HCC.

The study, named the PHOCUS trial, is designed to enroll 600 patients who have not received prior systemic treatment for their cancer, and they will be randomized to one of two treatment groups: one which will receive Pexa-Vec followed by sorafenib and one which will receive sorafenib alone. The randomized study will be conducted at approximately 140 sites worldwide including North America, Asia, Australia, and Europe. SillaJen reached agreement with the U.S. Food and Drug Administration (FDA) on a Special Protocol Assessment (SPA) for this global Phase 3 clinical trial. The primary objective of the study will be to determine the overall survival of patients treated with Pexa-Vec, followed by sorafenib versus sorafenib alone. Secondary objectives will include safety as well as assessments for tumor responses between the two groups as measured by the following endpoints: time to progression, progression-free survival, overall response rate and disease control rate. To learn more about the trial, please visit: http://www.pexavectrials.com/

"We are pleased to be initiating this multinational Phase 3 trial for Pexa-Vec—an oncolytic immunotherapy, which demonstrated antitumor activity in Phase 2 clinical trials for liver cancer," stated Eun Sang Moon, chief executive officer of SillaJen. "Our primary focus at this time is to execute a well-run, successful clinical trial, and we believe that the SPA that we have in place with the FDA will allow us and our global partners a clear path to approval for Pexa-Vec."

"We are still desperately in need of additional treatment options for advanced liver cancer. Cancer immunotherapy holds much promise, and I'm greatly looking forward to having the opportunity to evaluate Pexa-Vec in patients with advanced liver cancer," stated Ghassan Abou-Alfa, M.D. medical oncologist at Memorial Sloan Kettering Cancer Center and lead investigator on the Phase 3 trial.

Pexa-Vec Clinical Development Program and SOLVE Platform
Pexa-Vec is the most advanced product candidate from SillaJen's proprietary SOLVE™ (Selective Oncolytic Vaccinia Engineering) platform. The vaccinia strain backbone of Pexa-Vec has been used safely in millions of people as part of a worldwide vaccination program. This strain naturally targets cancer cells due to common genetic defects in cancer cells; Pexa-Vec was engineered to enhance this by deleting its thymidine kinase (TK) gene, thus making it dependent on the cellular TK expressed at persistently high levels in cancer cells. Pexa-Vec is also engineered to express the immunogenic GM-CSF protein. GM-CSF complements the cancer cell lysis of the product candidate, leading to a cascade of events resulting in tumor necrosis, tumor vasculature shutdown and sustained anti-tumoral immune attack.