Rechallenge immunotherapy after immune resistance in patients with advanced thymic carcinoma

Immunotherapy is effective for patients with advanced thymic carcinoma (TC). However, the effectiveness of rechallenge immunotherapy in patients who are resistant to immunotherapy has not been investigated.

Thirty-five patients with advanced TC using immunotherapy between 2016 and 2023 at Zhejiang Cancer Hospital, The Second Affiliated Hospital of Nanchang University, and Fujian Cancer Hospital were evaluated in this study. Tumor response was evaluated according to the Response Evaluation Criteria in Solid Tumors version 1.1. Progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method.

A total of 35 patients were included in this study. The median PFS (mPFS) for all patients was 5.43 months and the median OS (mOS) was 16 months. After rechallenge immunotherapy, only three patients achieved partial response, resulting in an overall response rate of 16.7%, and nine patients attained stable disease, resulting in a disease control rate of 66.7%. Patients who underwent rechallenge immunotherapy had shorter mPFS compared to chemotherapy (3.53 months vs. 6.00 months, P = 0.041). In addition, the incidence of Grade 3-4 treatment-related adverse events in these patients was 22.2%.

Rechallenge immunotherapy has poor efficacy in immunotolerant TC patients.