NCCN Guidelines for Patients® | Myeloproliferative Neoplasms

47 NCCN Guidelines for Patients ® : Myeloproliferative Neoplasms, 2018 5 Myelofibrosis Initial treatment What is ruxolitinib? Kinases are molecules that move chemicals, called phosphates, from one molecule to another. Kinase inhibitors stop the phosphates from being moved. Kinase inhibitors often block growth signals within cancer cells. This reduces the number of new cancer cells being made. Ruxolitinib is a kinase inhibitor. It stops a kinase called JAK ( J anus- a ssociated k inase). This kinase is part of a receptor on the inside of blood cells. See Figure 11 . Some receptors are the starting point in cells for growth signals. Ruxolitinib is sold as Jakafi ® . It is made in pill form and taken twice a day. It should be taken around the same times each day. Your doctor will tell you what dose you need. Do not stop or skip taking ruxolitinib without your doctor’s approval. Symptoms can return very quickly. Common side effects of ruxolitinib include low blood cell counts, bruising, dizziness, and headache. It can also increase your chances for infections, other cancers, and high cholesterol. Women who are pregnant, trying to get pregnant, or are breastfeeding should not take ruxolitinib. Not all side effects of ruxolitinib are listed here. Please ask your treatment team for a complete list of common and rare side effects. If a side effect bothers you, tell your treatment team. There may be ways to help you feel better. There are also ways to prevent some side effects. Figure 11 Ruxolitinib JAKs are protein kinases within growth signal pathways. Kinases move chemicals, called phosphates, from one molecule to another. The phosphate “turns on” the next molecule in the signal pathway. Ruxolitinib blocks the transfer of phosphate by JAKs and in turn stops cell growth signals. Copyright © 2017 National Comprehensive Cancer Network ® (NCCN ® ). MPN cell P JAK P JAK ruxolitinib