SCG Cell Therapy Pte Ltd (SCG), a clinical-stage biotechnology company focused on developing innovative immunotherapies for infectious diseases and associated cancers, announced late-breaking data from its Phase 1 trial of SCG101, a first-in-class autologous hepatitis B virus (HBV)-specific T-cell receptor-engineered T Cell (TCR-T) therapy targeting hepatitis B surface antigen (HBsAg). The data was presented at the 2024 AASLD Liver Meeting in San Diego, United States. 

In the Phase 1 clinical trial, SCG101 exhibited promising antiviral activity in patients with advanced HBV-related hepatocellular carcinoma (HBV-HCC). Among the 12 patients treated with a single intravenous dose of SCG101 at 5.0×10⁷ ~ 1.0×10⁸ TCR⁺ T cells/kg, all patients demonstrated a significant reduction in serum HBsAg levels, with 11 out of 12 (92%) patients achieving a reduction of 1.0 to 4.6 log₁₀, and the levels remaining below 100 IU/mL throughout the follow-up period of up to one year. Notably, four patients (33%) experienced HBsAg loss within 21 days following a single infusion of SCG101 and which persisted throughout the follow-up.

The safety profile of SCG101 was generally favourable, with the therapy being well tolerated. The most commonly reported treatment-related adverse events included transient elevations in liver enzymes, pyrexia, cytopenia, cytokine release syndrome (CRS), hypoalbuminemia, and hyponatremia—consistent with SCG101's mechanism of action, which involves the HBsAg-targeted immune activation and its mediated clearance of diseased hepatocytes and HCC cells. 

HBV remains a major global health burden, affecting over 250 million people worldwide. It is a leading cause of liver cancer, responsible for 50%–80% of hepatocellular carcinoma cases globally.¹ Chronic HBV infection leads to the integration of HBV DNA into the host genome, resulting in persistent HBsAg expression, chromosomal instability, and activation of oncogenes, thereby contributing to the development of hepatocellular carcinoma.² SCG101 is designed to target a specific HBV peptide presented on infected cells, as well as hepatocytes with HBV DNA integration. By triggering both cytolytic and non-cytolytic mechanisms, SCG101 effectively eliminates HBV-infected hepatocytes as well as premalignant and HBV-HCC cells with HBV-DNA integration.  

"The positive data from our Phase 1 trial marks a significant milestone in the development of SCG101, our first-in-class HBV-specific TCR-T therapy. These results not only demonstrate the potential of SCG101 to achieve meaningful and durable antiviral responses in patients, but also underscore the unique approach we are taking in HBV-specific TCR T cell therapy. We are encouraged by these early findings and are committed to advancing SCG101 through clinical development as we work towards providing a new therapeutic option for patients suffering from this challenging disease", said Christy Ma, Chief Executive Officer of SCG Cell Therapy. "We believe our GianT^TM TCR discovery platform has the potential to address a broad spectrum of infection-associated cancers, such as human papillomavirus (HPV) associated cervical cancer and head and neck cancer, and Epstein-Barr virus (EBV) associated nasopharyngeal carcinoma and gastric cancer, paving the way for a new paradigm in immune-based cancer treatment".