Dr. Mesa on the Safety Profiles of JAK Inhibitors in Myelofibrosis

Ruben Mesa, MD, the director of the Mays Cancer Center at UT Health San Antonio MD Anderson Cancer Center, discusses the adverse events associated with ruxolitinib (Jakafi) and fedratinib (Inrebic) in myelofibrosis.

It is known that both ruxolitinib and fedratinib can cause anemia and thrombocytopenia in these patients, but additional differences in adverse events may be discovered over time, explains Mesa. The duration of treatment can also have an effect on safety. For example, a longer duration of treatment with ruxolitinib can cause increased rates of non-melanoma skin cancers and certain infections, such as herpes zoster infection, says Mesa.

The safety profile of fedratinib in relation to its duration of use is not fully understood yet, but research will continue to follow the agent over time, says Mesa. Fedratinib is associated with additional toxicities compared with ruxolitinib that need to be monitored. For example, some gastrointestinal disturbances have been observed with the agent. However, in studies examining the agent, investigators showed that pretreating patients with antinausea and antidiarrheal medications aggregated those symptoms to a significant degree and did not cause major issues, concludes Mesa.