Phase I dose-escalation trial of checkpoint kinase 1 inhibitor MK-8776 as monotherapy and in combination with gemcitabine in patients with advanced solid tumors.

PURPOSE: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Combinatorial approach to treatment of melanoma.

There are multiple effective and well-tolerated systemic therapy treatments for the treatment of advanced melanoma, as well as new immunotherapy and targeted therapy agents in clinical trials. Traditional cytotoxic chemotherapy and targeted BRAF inhibitors can increase antigen presentation and can rebalance the intratumoral immune milieu. The combination of pulsed cytotoxic therapy and immunotherapy is a logical next step in designing treatment regimens. Combination radiotherapy and immunotherapy also has experimental and clinical support. The standard of care for patients with advanced melanoma remains participation in clinical trials in order to enhance understanding of the effectiveness and toxicities of combination regimens.

Management of a patient with advanced BRAF-mutant melanoma.

A 49-year-old man initially diagnosed in 1995 with cutaneous melanoma presented to the authors' institution in 2009 with metastatic, BRAF V600E-mutant melanoma. His treatment course to date has included surgery, adjuvant radiotherapy, and interferon, metastasectomies, granulocyte-macrophage colony-stimulating factors, a clinical trial with the BRAF inhibitor vemurafenib (PLX-4032), clinical trial with combination BRAF plus MEK inhibition with vemurafenib plus GDC-0973, and combination targeted and immune therapy with vemurafenib plus the anti-CTLA4 antibody ipilimumab. This case report illustrates the long-term management of a patient with metastatic melanoma using targeted and immune therapy, evolution in treatment guidelines, next directions in research, and the critical role of clinical trials in advancement of patient care.