You will take ruxolitinib by mouth 2 times every day (about 12 hours between each dose). You can take the drug with or without food, but you need to take it with about 1 cup (8 ounces) of water. If you forget to take a scheduled dose, you should take the study drug within 3 hours after the missed dose. If more than 3 hours have passed since your missed dose, then you should wait to take the study drug until your next scheduled dose.