TScan Therapeutics Begins Phase 1 Trial for TCR-T Therapy in Solid Tumors

TScan Therapeutics, Inc., a biopharmaceutical company specializing in T cell receptor-engineered T cell (TCR-T) therapies for cancer treatment, has dosed the first patient in its Phase 1 clinical trial for solid tumors. The patient, suffering from metastatic melanoma, received TSC-203-A0201, targeting the PRAME cancer-associated antigen. This marks a significant milestone for the company, which is also manufacturing TCR-T products for three additional patients.

Chief Executive Officer Gavin MacBeath, Ph.D., emphasized the importance of this milestone, noting the excitement surrounding the trial and the company's efforts in producing more TCR-T products. The company has six TCR-Ts cleared under existing IND applications and plans to file more to expand its ImmunoBank, which includes therapeutic TCRs targeting various antigens and HLA types. This strategy aims to broaden the reach of multiplex TCR-T therapy for solid tumors.

Chief Medical Officer Chrystal U. Louis, M.D., highlighted that solid tumors are highly heterogeneous, making a multi-faceted treatment approach essential. The customized multiplex TCR-T therapy aims to provide durable responses by overcoming tumor heterogeneity and the resistance developed from target or HLA loss. Initial data from the solid tumor trial is expected later this year.

TScan’s Phase 1 clinical trial evaluates the safety and feasibility of T-Plex, an autologous TCR-T therapy targeting multiple peptide/HLA targets in patients with advanced, unresectable, or metastatic solid tumors. This multiplex approach has the potential to address the common resistance mechanisms in solid tumors, which include tumor heterogeneity and HLA loss of heterozygosity.

First-generation TCR-T therapies targeting single antigens have shown promising yet limited responses. TScan's approach of administering multiple TCR-Ts targeting different cancer-associated antigens aims for higher and longer-lasting response rates. The company screens patients with various cancers, such as melanoma, non-small cell lung cancer (NSCLC), head and neck cancer, cervical cancer, ovarian cancer, and anogenital cancers, for target expression and intact HLA genes. Eligible patients receive one or more investigational TCR-T products matched to the antigens expressed in their tumors.

The company’s ImmunoBank currently includes six TCR-T clinical candidates: TSC-203-A0201 (PRAME, HLA-A*02:01), TSC-200-A0201 (HPV16, HLA-A*02:01), TSC-201-B0702 (MAGE-C2, HLA-B*07:02), TSC-204-A0201 (MAGE-A1, HLA-A*02:01), TSC-204-C0702 (MAGE-A1, HLA-C*07:02), and TSC-204-A0101 (MAGE-A1, HLA-A*01:01). TScan aims to expand this repository to include TCR-Ts for additional targets and HLA types, thereby increasing patient eligibility for multiplex therapy.

TScan Therapeutics focuses on developing TCR-engineered T cell therapies for cancer treatment. Their leading TCR-T candidates, TSC-100 and TSC-101, target hematologic malignancies to prevent relapse after allogeneic hematopoietic cell transplantation. The company is also advancing multiplexed TCR-T candidates for various solid tumors and expanding its ImmunoBank to offer customized TCR-T therapies for diverse cancer types.