Titin mutation associated with responsiveness to checkpoint blockades in solid tumors

Area of Science:

• Oncology
• Immunotherapy
• Genomics

Background:

• Immune checkpoint blockade (ICB) immunotherapy shows promise against solid tumors but has limited response rates.
• Tumor mutational burden (TMB) is an emerging biomarker for ICB response, but current surrogate biomarkers identify only small patient subsets.
• Many potential responders to ICB are missed due to limitations of existing predictive biomarkers.

Purpose of the Study:

• To investigate titin (TTN) mutations as a novel predictive biomarker for ICB immunotherapy response.
• To assess the association between TTN mutations, TMB, and clinical outcomes in patients with solid tumors treated with ICB.

Main Methods:

• Analysis of 7 public clinical cohorts involving patients with solid tumors treated with ICB.
• Evaluation of the correlation between TTN mutation status, TMB levels, and objective response rates.
• Assessment of progression-free survival (PFS) and overall survival (OS) based on TTN mutation status.

Main Results:

• Mutations in TTN were frequently detected in solid tumors and were associated with increased TMB.
• Patients with mutated TTN demonstrated significantly longer PFS and OS compared to those with wild-type TTN across multiple cohorts.
• An improved objective response rate to ICB was observed in patients with TTN mutations, alongside higher TMB.

Conclusions:

• TTN mutation serves as a clinically feasible biomarker for predicting improved outcomes in response to ICB immunotherapy.
• Identifying TTN mutations can help estimate TMB and guide patient selection for ICB therapy, potentially expanding the pool of responders.