SCG Cell Therapy Announces Breakthrough Clinical Data of SCG101 TCR-T Therapy Demonstrating 74.5% Tumor Reduction and 100% HBV Clearance

Tumor Shrinkage74.5%`, Hepatitis B infection`100%Clear

SingaporeJune 5, 2023/PR Newswire/ --SCG(SCG), an innovative immunotherapy company focused on infections and their associated cancers, announced the latest breakthrough clinical data for its hepatitis B virus antigen-specific T cell receptor (TCR) T cell therapy (research code: SCG101) at the Late-breaking Clinical Trial Report session of the International Society for Cell & Gene Therapy (ISCT) held in Paris, France.

Clinical data show that SCG101 has significant anti-tumor and antiviral activity. In a patient with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), the target tumor lesion shrank by 66% compared to baseline on day 28 after a single infusion of SCG101, achieving partial response (PR), and further reduced by 74.5% in the fourth month; another lesion completely disappeared. The patient did not receive any other anti-tumor treatments during the trial period. At the time of data cutoff, the tumor had remained without progression for over 6.9 months, maintaining a sustained response.

Based on the liver immunohistochemical analysis before and after infusion, hepatitis B surface antigen-positive hepatocytes were completely cleared by 100%. The HBV serological marker HBsAg decreased from 557.96 IU/mL before SCG101 infusion to 1.3 IU/mL on the 7th day after infusion, and further dropped to 0.08 IU/mL on the 28th day.

Liver cancer is the sixth most common cancer globally, with more than 900,000 new cases each year. Hepatitis B virus (HBV) infection is the leading cause of liver cancer, and HBV-related hepatocellular carcinoma accounts for over 80% of liver cancer cases in China. After HBV infection, viral DNA integrates into the host genome, which can lead to genomic instability of the host cells, expression of virus-associated oncogenes, and trigger inflammatory and oxidative stress responses, causing abnormal regeneration of liver cells. Ultimately, multiple mechanisms contribute to the development of hepatocellular carcinoma.

SCG101 is a hepatitis B antigen-specific TCR-T cell therapy that can specifically target HBV antigen-related T-cell epitopes, effectively eliminating HBV-HCC tumor cells, HBV-DNA integrated precancerous lesion cells, and HBV-infected cells.。

Dr. Ke Zhang, Chief Scientific Officer of SCG Cell Therapy Pte. Ltd., stated: "The tumor microenvironment is a key barrier that limits the efficacy of cancer immunotherapy. By targeting and eliminating HBsAg-positive hepatocytes and precancerous lesion cells with HBV integration around the tumor tissue, SCG101 TCR-T cells can be fully activated and expanded before entering the tumor microenvironment. Additionally, through the secretion of multiple cytokines, SCG101 modulates the inherently immunosuppressive microenvironment of the liver, enhances T-cell tumor infiltration, breaks immune tolerance, and triggers endogenous anti-tumor immune responses. This unique mechanism of SCG101 effectively addresses a common challenge faced by T-cell therapies in solid tumors."

Dr. Zhang Ke added: "In the analysis of immune-related biomarkers, SCG101 demonstrated unique CD8/CD4 dual T-cell functional activity. After SCG101 infusion, significant expansion of TCR-T cells was observed in patients, showing a favorable balance of CD8+:CD4+ TCR-T cell ratios, which helps enhance T-cell interaction and assist in amplification, improving anti-tumor responses. Meanwhile, a high proportion of stem cell-like memory T cells (Tscm) were observed to expand and persist long-term, forming specific memory T-cell subsets that enable SCG101’s long-term self-renewal capability and functionality, sustaining continuous anti-tumor and anti-viral effects."

Wang Shuli, CEO of SCG Cell Therapy Pte. Ltd., stated: "The effective and long-lasting anti-tumor and antiviral functions demonstrated by SCG101 bring significant benefits to patients, which is very exciting. We look forward to developing more TCR-T cell therapy products that can play a greater role in overcoming solid tumors, bringing benefits to more patients."