mk-8776 and Adenocarcinoma

We determined the safety, pharmacokinetics, pharmacodynamics, and recommended phase II dose of MK-8776 (SCH 900776), a potent, selective checkpoint kinase 1 (Chk1) inhibitor, as monotherapy and in combination with gemcitabine in a first-in-human phase I clinical trial in patients with advanced solid tumor malignancies.. Forty-three patients were treated by intravenous infusion with MK-8776 at seven dose levels ranging from 10 to 150 mg/m(2) as monotherapy and then in combination with gemcitabine 800 mg/m(2) (part A, n = 26) or gemcitabine 1,000 mg/m(2) (part B, n = 17). Forty percent of patients had three or more prior treatment regimens, and one third of patients had previously received gemcitabine.. As monotherapy, MK-8776 was well tolerated, with QTc prolongation (19%), nausea (16%), fatigue (14%), and constipation (14%) as the most frequent adverse effects. Combination therapy demonstrated a higher frequency of adverse effects, predominantly fatigue (63%), nausea (44%), decreased appetite (37%), thrombocytopenia (32%), and neutropenia (24%), as well as dose-related, transient QTc prolongation (17%). The median number of doses of MK-8776 administered was five doses, with relative dose-intensity of 0.96. Bioactivity was assessed by γ-H2AX ex vivo assay. Of 30 patients evaluable for response, two showed partial response, and 13 exhibited stable disease.. MK-8776 was well tolerated as monotherapy and in combination with gemcitabine. Early evidence of clinical efficacy was observed. The recommended phase II dose is MK-8776 200 mg plus gemcitabine 1,000 mg/m(2) on days 1 and 8 of a 21-day cycle.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Checkpoint Kinase 1; Cohort Studies; Cytarabine; Deoxycytidine; Female; Gemcitabine; Histones; Humans; Infusions, Intravenous; K562 Cells; Male; Melanoma; Middle Aged; Neoplasms; Protein Kinase Inhibitors; Protein Kinases; Pyrazoles; Pyrimidines; Sarcoma; Time Factors