An Independent Data Monitoring Committee has recommended that SillaJen discontinue their phase 3 trial of Pexa-Vec (formerly JX-594) in patients with advanced hepatocellular carcinoma (HCC) following the evaluation of results from a formal pre-planned futility analysis. 

Pexa-Vec, a vaccinia virus based immunotherapy, was designed to target common genetic defects in cancer cells by deleting the thymidine kinase (TK) gene. Based on the findings of the futility analysis, the Company stated that it has decided to discontinue the trial.

The primary outcome measure of the trial (PHOCUS) was overall survival in HCC patients treated with Pexa-Vec, followed by sorafenib vs sorafenib alone. Although the committee found that the treatment was well tolerated, the interim results suggested that it was unlikely to significantly improve overall survival. 

Related Articles

“The interim results are a disappointment to the company,” said Dr Eun Sang Moon, CEO of SillaJen. “The discontinuation of the study will allow us to focus on a more promising development program.”

The PHOCUS trial included 600 patients who had not received prior systemic treatment. In a statement, the Company said “SillaJen thanks the patients, caregivers and investigators involved in our clinical study and will continue to seek effective treatments for cancer patients.”

For more information visit