Thymoma is usually treated with surgery. Where surgery is inappropriate, chemotherapy concurrent with, or sequential to, radiation therapy is recommended. Cisplatin-based combination chemotherapy is an appropriate option. Octreotide, alone or in combination with a corticosteroid, may be a reasonable option for recurrent cases. A recent Phase II study revealed that complete responses (CR) and partial responses were observed in three (20%) and three (20%) patients for a 40% RR, respectively. Grade 1–2 neutropenia, anemia and thrombocytopenia were the most common side-effects, noted in seven (46.7%), five (33.3%) and five (33.3%) patients, respectively. The most common grade 3 toxicity was neutropenia in three patients (20%). Median PFS was 11 months (95% confidence interval 4–17). The 1- and 2-year survival rates were 80% and 67%, respectively. There are other phase II trials that also suggest that cepacitabine in combination is effective.

A phase II study by Giaccone suggested that: “Pembrolizumab is a promising treatment option in patients with thymic carcinoma. Because severe autoimmune disorders are more frequent in thymic carcinoma than in other tumour types, careful monitoring is essential. This is not a definitive study.

. Giaccone et al, Pembrolizumab in patients with thymic carcinoma: a single-arm, single-centre, phase 2 study The Lancet Oncology Volume 19, Issue 3, March 2018, Pages 347-355

Falkson C, Bezjak A, Darling G, Gregg R, Malthaner R, Maziak D, Yu E, Smith CA, McNair S, Ung Y, Evans WK, Lung Disease Site Group. The management of thymoma: guideline recommendations. Toronto (ON): Cancer Care Ontario Program in Evidence-based Care; 2008 Sep 26. 41 p. (Evidence-based series; no. 7-11). [58 references]

G. Palmieri , G. Merola , P. Federico , L. Petillo , M. Marino , M. Lalle , M. Milella , A. Ceribelli , L. Montella , C. Merola , S. Del Prete , M. Bergaglio , S. De Placido , and G. Di Lorenzo
Preliminary results of phase II study of capecitabine and gemcitabine (CAP-GEM) in patients with metastatic pretreated thymic epithelial tumors (TETs)
Annals of Oncology Advance Access published on October 30, 2009, DOI 10.1093/annonc/mdp483.

Palmieri, G., Merola, C., Petillo, L., Merola, G., Federico, P., Leopardo, D., Marino, M., Montella, L.
Gemcitabine-capecitabine in platinum-refractory patients with thymic epithelial tumors
J Clin Oncol (Meeting Abstracts) 2009 27: 7590