This is an open-label, nonrandomized phase 2 trial to assess the efficacy of cobimetinib in RAS pathway activated CMML. Two cohorts of patients will be accrued using Simon's two-stage design (Simon, 1989) for both cohorts. Cohort 1 will enroll nine newly diagnosed patients in the first stage and if four or more responses are observed five additional patients will be enrolled in the second stage. Cohort 2 will enroll six HMA refractory patients in the first stage and if one or more responses are observed then nine additional patients will be enrolled in the second stage.~All eligible patients will be treated daily with cobimetinib in 28-day cycles. Cobimetinib will be administered consecutively for three weeks followed by a one week break prior to the start of the following cycle. Patients will remain on study therapy until treatment discontinuation criteria is met.
This is an open-label, nonrandomized phase 2 trial to assess the efficacy of cobimetinib in RAS pathway activated CMML.~All eligible patients will be treated daily with cobimetinib in 28-day cycles. Cobimetinib will be administered for three weeks followed by a one week break prior to the start of the following cycle. Patients will remain on study therapy until treatment discontinuation criteria is met.