Antitumor activity in advanced cancer patients with thymic malignancies enrolled in early clinical drug development...

Thymic epithelial neoplasms (TENs) represent a rare entity with poor prognosis and limited systemic treatment options. The aim of this study was to assess the clinical benefit, the efficacy and toxicities of agents for patients with TEN enrolled in Phase I trials.

We reviewed retrospectively patients with advanced TEN enrolled in Phase I trials at Gustave Roussy (DITEP) between 1994 and 2012. Efficacy was assessed using RECIST version 1.1.

Twenty-two treated patients were enrolled (15 with thymic carcinoma, 7 with thymoma). The median number of prior systemic therapies was 2 (0-8). The median age was 50 years (range 23-72), and 4 females were treated. Treatments received encompassed mTOR inhibitor (mTORi) in 4 of patients, antiangiogenic agents (AA) in 11 patients, and other targeted therapies in 7 patients. 18% had grade 3-4 toxicity, 85% all grade toxicity and no toxic death was reported. One patient experienced a complete response (CR) and 3 a partial response (PR); 16 patients had stable disease (median 6.6 months; range 1.0-30.7) and 2 had a progressive disease. The median overall survival was 54.5 months (95% CI 25-75.50). The median progression free survival (PFS) was 6.6 months (95% CI 1.35-11.59). Median PFS was 11.6 months for mTORi, 6.9 for AA, and 6.6 for other targeted therapies.

Phase I trials appear as a sound therapeutic option in TENs pts progressing after standard treatments. Use of AA and mTORi seem to yield a good clinical response and warrant further investigation.