Deciphera Pharmaceuticals, Inc. announced positive, preliminary, top-line data from the ongoing dose escalation part of the Phase 1 clinical study with DCC-3014, the Company’s investigational small molecule switch control inhibitor of CSF1R, in patients with advanced malignancies. In addition, the Company announced a plan to expand the Phase 1 study to evaluate DCC-3014 in patients diagnosed with Tenosynovial Giant Cell Tumors (TGCT). A review of further data from this Phase 1 study will be presented at a medical meeting in 2019. The Phase 1 study was designed to evaluate the safety, pharmacokinetics and pharmacodynamics of multiple doses of DCC-3014 in up to 55 patients. As of the data cut-off date of November 9, 2018, increasing doses of DCC-3014 were assessed in five dose cohorts across 24 patients with advanced solid tumor malignancies. This included one dose cohort that received 10 mg once daily (QD) and four dose cohorts that followed a schedule of once or twice-weekly maintenance dosing preceded by a five-day loading dose regimen at doses of up to 30 mg per dose. In addition, four patients are currently enrolled in a dose cohort that will receive 40 mg twice weekly preceded by a five-day loading regimen. Preliminary pharmacokinetic (PK) analysis showed dose-proportional exposure for DCC-3014 that believe supports twice-weekly maintenance dosing preceded by a five-day loading dose regimen. Biomarker data demonstrated strong target engagement of CSF1R, including material reductions in CSF1R positive macrophages in the blood that believe constitutes mechanistic proof-of-concept (mPoC) for DCC-3014. DCC-3014 was generally well tolerated in patients enrolled in the dose cohorts that received twice-weekly maintenance doses of DCC-3014 preceded by a five-day loading regimen at doses of up to 30 mg, which is summarized below: Treatment emergent adverse events (TEAEs) were mostly Grade 1 or 2; No Grade 3 or 4 DCC-3014 related TEAEs in =10% of patients; No dose-limiting toxicities; and A maximum tolerated dose has yet to be established.