Key clinical point: Circulating tumor DNA can be used for mutational profiling and responses assessment in patients with advanced imatinib-resistant GIST. Identification of ctDNA by next-generation sequencing was accomplished in the majority of patients, with findings that support the need for a broad-spectrum KIT inhibitor for patients with GIST resistant to imatinib (Gleevec).
Major finding: Of 73 patients with detectable KIT mutations by ctDNA at baseline, 35 became KIT ctDNA negative during at least one treatment time point.
Study details: Subanalyses from a phase 1 trial of the investigational agent DCC-2618, a pan-KIT/platelet-derived growth factor receptor alpha (PDGFRA) switch control inhibitor.
Disclosures: The trial is supported by Deciphera Pharmaceuticals. Dr. George disclosed stock or other ownership in Abbott Laboratories and Abbvie, consulting/advising for AstraZenece, Blueprint Medicines, and Deciphera, and institutional research funding from Ariad, Bayer, Blueprint Medicine, Deciphera, Novartis, and Pfizer.
Source: George S et al. ASCO 2018. Abstract 11511.
George S et al. ASCO 2018. Abstract 11511.
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Must Reads in Sarcoma & GIST
Liquid biopsy aids assessment in advanced imatinib-resistant GIST, George S et al. ASCO 2018. Abstract 11511.
Rapid therapy changes fall short for metastatic GIST, Serrano-Garcia C et al. ASCO 2018, Abstract 11510.
Adjuvant doxorubicin and ifosfamide boost outcomes in soft tissue sarcomas, Pasquali S et al. ASCO 2018, Abstract 115118.
Two novel TKIs better than one in GIST with multiple KIT mutations, Wagner AJ et al. ASCO 2018, Abstract 11509.
PFS better with trofosfamide than doxorubicin in elderly patients with untreated metastatic soft-tissue sarcomas, Hartman JT et al. ASCO 2018, Abstract 11507.