This is a Phase I/II clinical trial. A Phase I clinical trial tests the safety of investigational drugs or new combinations of approved drugs. In addition, a Phase I study tries to define the appropriate dose of the investigational drugs to use for further studies. "Investigational" means that the drugs are being studied. Following the phase I study, additional participants will be enrolled to the Phase II component. The phase II component will test the safest doses of alectinib and cobimetinib (as identified in the Phase I component) in a larger group of patients.