Targeted Therapy Produced Durable Responses in Patients With Sarcoma
Three patients with soft tissue sarcoma experienced a confirmed clinical response following treatment with entrectinib, according to study results presented at the 2017 Connective Tissue Oncology Society Annual Meeting (November 8-11, 2017; Maui, HI).
Entrectinib is a multikinase inhibitor that has shown high objective response rates in phase 1 studies, along with a tolerable safety profile. The agent inhibits TRK, ROS1, and ALK mutations, and has also shown activity in the central nervous system.
Kumar Sankhala, MD, codirector of sarcoma medical oncology and director of clinical research at Cedars-Sinai Medical Center (Los Angeles, CA), presented data from the ongoing STARTRK-2 basket trial, which has enrolled patients with gene fusions across solid tumor types. Patients on trial are treated with a 600 mg daily dose of entrectinib.
Dr Sankhala reported on three sarcoma patients: a 49-year-old woman with endometrial stromal sarcoma that metastasized to her lung and kidney; a 60-year-old woman with leiomyosarcoma that metastasized to her abdomen, liver, pelvis, and right retroperitoneum; and a 72-year-old woman with uterine leiomyosarcoma. All three patients had actionable mutations.
The study reported that the patient with endometrial stromal sarcoma achieved a 30.2% reduction of her tumor burden, which increased to a 79% overall reduction from baseline.
The patient metastatic leiomyosarcoma achieved a complete response and remained on study at the time of reporting, after 7 months of treatment.
The patient with uterine leiomyosarcoma also remained on study at the time of reporting, after 13 months, and had achieved a partial response of 32% of her tumor burden after 8 cycles of entrectinib.
Dr Sankhala remarked that patients should be tested for potential actionable mutations in order to identify who may best benefit from treatment with targeted agents like entrectinib.—Cameron Kelsall