• Shinji Nakamichi, Hiroshi Nokihara, Noboru Yamamoto, Yasuhide Yamada, Yutaka Fujiwara, Yosuke Tamura, Hiroshi Wakui, Kazunori Honda, Hidenori Mizugaki, Satoru Kitazono, Yuko Tanabe, Hajime Asahina, Naoya Yamazaki, Shigenobu Suzuki, Mieko Matsuoka, Yoshitaka Ogita, and Tomohide Tamura.
• Department of Thoracic Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, Japan.
• Invest New Drugs. 2015 Jun 1; 33 (3): 641-51.

AbstractRO4987655 is an oral and selective inhibitor of MEK, a key enzyme of the mitogen-activated protein kinase (MAPK) signaling pathway. This phase I dose-escalation study of RO4987655 in Japanese patients with advanced solid tumors aimed to determine maximum tolerated dose (MTD) and to evaluate safety, pharmacokinetics (PK), pharmacodynamics (PD), and anti-tumor activity. Patients received a single dose of RO4987655 (1, 2, 4, 5, or 6.5 mg) followed by continuous once-daily dosing (1, 2, or 4 mg QD) or twice-daily dosing (4, 5, or 6.5 mg BID) in 28-day cycles. A 3 + 3 dose-escalation design was used. PD was evaluated by pERK inhibition in peripheral blood mononuclear cells (PBMCs). In dose-escalation, 25 patients were enrolled. After the MTD was determined, a further six patients were administered the MTD for further confirmation of safety. MTD was determined as 8 mg/day (4 mg BID) due to a total of four dose-limiting toxicities (DLTs) of grade 3 creatine phosphokinase (CPK) elevation (2 DLTs each in 10 mg/day and 13 mg/day). Most commonly related adverse events included dermatitis acneiform, CPK elevation, and eye disorders. Plasma concentration of RO4987655 appeared to increase in a dose-proportional manner with a plasma half-life of 4.32 to 21.1 h. Following multiple dose administration, a steady-state condition was reached by Cycle 1 Day 8. The inhibitory effects of RO4987655 on pERK in PBMCs increased in a dose-dependent manner. One esophageal cancer patient had confirmed partial response and seven patients showed progression-free survival for longer than 16 weeks. The MTD of RO4987655 for Japanese patients was determined as 8 mg/day (4 mg BID). RO4987655 was tolerated up to the MTD with a favorable PK/PD profile in Japanese patients with advanced solid tumors.

37 keywords...

hide…