Response Assessment: Monitoring Parameters and Molecular Testing Integration
Panelists discuss how to monitor patients on JAK inhibitors, including blood count checks every 1 to 2 weeks initially, baseline spleen imaging with follow-up at 3 to 6 months, and symptom burden assessment.
This segment explores the role of pacritinib in myelofibrosis treatment and factors influencing JAK inhibitor selection. Dr Rampal describes pacritinib as a valuable addition to the treatment arsenal, particularly for patients with profound thrombocytopenia. For the case patient with relatively high platelets, pacritinib wouldn’t be the first choice unless other JAK inhibitors were contraindicated. However, if the patient’s platelets dropped dramatically requiring dose attenuation of their current JAK inhibitor, pacritinib would be an excellent alternative since it can be used at full dose regardless of platelet count.
When discussing patient-specific factors in JAK inhibitor selection, Dr. Rampal highlights that pacritinib and fedratinib have notable gastrointestinal toxicities that typically diminish over time. Fedratinib carries a black box warning for Wernicke encephalopathy, while ruxolitinib and momelotinib are associated with secondary malignancies and infections, possibly due to JAK1 inhibition. These considerations are particularly important for patients with latent tuberculosis or recurrent zoster infections.
For monitoring patients on JAK inhibitors, Dr Rampal recommends checking blood counts every 1 to 2 weeks initially due to expected cytopenias. Baseline spleen imaging with follow-up at 3 and 6 months is important since spleen reduction correlates with survival. Prior to starting ruxolitinib, he advises checking for latent tuberculosis and ensuring patients have received shingles vaccination. Dr Vachhani adds that baseline imaging is valuable since physical exams may miss the full extent of splenomegaly, and standardized symptom assessment tools like MPN-SAF forms help quantify symptom burden objectively.
