Atezolizumab with bevacizumab, paclitaxel and carboplatin was effective for patients with SMARCA4-deficient thoracic sarcoma
Hayato Kawachi, Kei Kunimasa, Yoji Kukita, Harumi Nakamura, Keiichiro Honma, Takahisa Kawamura, Takako Inoue, Motohiro Tamiya, Hanako Kuhara, Kazumi Nishino, Yu Mizote, Takashi Akazawa, Hideaki Tahara, Toru Kumagai
Abstract
SMARCA4-deficient thoracic sarcoma (DTS) is a recently noted progressive thoracic malignancy. We recently experienced three cases of SMARCA4-DTS who were treated with atezolizumab in combination with bevacizumab, paclitaxel and carboplatin (ABCP) as the first-line therapy. Immunohistopathological analysis revealed absent expression of SMARCA4 in all cases. The tumor mutational burden was over 11/Mb and mutations in SMARCA4 and TP53 were detected in all three cases. Partial response to ABCP treatment was observed in all three cases, with a progression-free survival of approximately 6 months or longer and a continuous response of 1 year or longer in one case. The first-line ABCP treatment demonstrated durable efficacy in SMARCA4-DTS regardless of the degree of PD-L1 expression.