Pembrolizumab in patients with recurrent thymic carcinoma: Results of a phase II study.

Abstract

8573 Background: There are few treatment options for thymic carcinoma after chemotherapy. We completed a single institution phase II study of pembrolizumab (P) in patients with recurrent thymic carcinomas. Methods: Main eligibility criteria included: progression after ≥ 1 chemotherapy line, ECOG PS 0-2, no history of autoimmune disease, and adequate organ function. P was given at 200mg IV every 3 weeks. The primary objective of the study was response rate (RR) by RECIST v1.1 criteria; secondary objectives were PFS and OS, and safety. Results: From 3/2015 to 12/2016 we accrued 41 patients. Of 40 eligible patients, 29 were male, 19 Caucasians, median age was 57 years (range 25-80), 14 had squamous carcinoma histology, and 19 ECOG PS 0. Median number of cycles delivered was 6 (range 1-31). The most common side effects were mild fatigue (10), diarrhea (4) and rhinorrhea (4). Six patients developed multiple grade 3-4 immune-relates AEs (irAEs): myocarditis/myositis (1), myositis/myocarditis/hepatitis/myasthenia gravis (1), myositis/hepatitis (1), bullous pemphigoid (1), hepatitis (1), hepatitis/pancreatitis/diabetes mellitus type 1 (1). There were no treatment related deaths. The 2 patients who developed myocarditis required a pacemaker. Three patients interrupted treatment because of irAEs (all responders) and 3 because of progression around the time of the irAE. irAEs were more frequent in females (4/6; p = .026). Five patients developed hypothyroidism and 1 hyperthyroidism. RR assessed in all 40 eligible patients was 22.5%: 1 complete response, 8 partial responses (plus 1 unconfirmed), 20 stable disease and with 11 progressions. Two partial responses show minimal residual disease with no PET uptake. Two responders have progressed and 5 responses are beyond 12 months duration. Of 29 cases tested for PD-L1 staining (Dako 22C3), high PD-L1 (≥50% tumor cells positive) was seen in 8 (28%); 6/9 responders had high PD-L1 expression. Targeted NGS in 15 cases did not show correlation between mutational burden and response. Conclusions: P has activity in patients with thymic carcinoma. irAEs are more frequent than in other tumors. Further analysis of NGS, Nanostring and PD-L1 expression and updated survival will be presented. Clinical trial information: NCT02364076.

Expression of PD-L1 and other immunotherapeutic targets in thymic epithelial tumors

“…Indeed, clinical trials evaluating the use of these agents in the treatment of thymic carcinoma are already underway and have demonstrated promising preliminary clinical activity. [ 20 ]…”

Response to Nivolumab as Salvage Therapy in a Patient with Thymic Carcinoma

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Progress in the Management of Advanced Thoracic Malignancies in 2017

“…3 A twin phase II study testing pembrolizumab in patients with thymic carcinoma showed an ORR of 22.5% and again a high incidence of irAEs (myocarditis, hepatitis, and thyroid disfunctions) probably because of a worsening of autoimmune disorders typically observed in patients with thymic malignancies. 140…”