SillaJen Files REN026 Clinical Study Report with FDA for RCC Patients

South Korean biotech firm SillaJen, Inc. has reported positive findings from its clinical trial combining Pexa-Vec with cemiplimab, a treatment for renal cell carcinoma (RCC). Pexa-Vec is a genetically modified virus designed to combat cancer, while cemiplimab, marketed as Libtayo, is an immunotherapy drug developed by Regeneron Pharmaceuticals.

The clinical study, known as REN026, was initiated after SillaJen and Regeneron entered into a partnership in 2017. It involved 95 participants across the U.S., South Korea, and Australia and concluded in February 2023. The trial was divided into four arms to evaluate the combined therapy's safety and efficacy.

Particularly noteworthy were the results from Arm C, which included patients new to immune checkpoint inhibitors (ICIs). This group showed an overall response rate (ORR) of 23.3% and a median overall survival (OS) of 25.13 months, outperforming the other arms. Arm D, consisting of patients who had previously received ICI treatment, also showed promising results with an ORR of 17.9%.

The study's methodology involved administering Pexa-Vec either intratumorally or intravenously, alongside cemiplimab infusions. The treatment was generally well-tolerated, with pyrexia being the most common adverse event. Importantly, no Grade 5 (fatal) events were reported.

SillaJen's Pexa-Vec is part of the company's SOLVE™ platform, which focuses on developing oncolytic vaccinia viruses. As of March 31, 2023, Pexa-Vec has been used to treat 595 cancer patients in international clinical trials. The virus is engineered to target cancer cells with high levels of thymidine kinase (TK) and to stimulate an immune response by expressing GM-CSF.

SillaJen is a publicly traded company on the KOSDAQ stock exchange, developing innovative cancer therapies with products like Pexa-Vec and BAL0891, a mitotic checkpoint inhibitor. They are also working on the GEEV® platform, which allows for the intravenous delivery of vaccinia viruses to tumors while avoiding the immune system's defenses.

The positive outcomes of the REN026 study could potentially pave the way for a new standard of care for patients with metastatic or unresectable RCC, offering hope for those who have not responded well to existing treatments.