QHow do you manage lab monitoring for JAK inhibitors?

JAK inhibitors have revolutionized dermatology, allowing us to provide an improvement in quality of life for patients like never seen before. Even though majority of patients tolerate them very well, each JAK inhibitor carries risks of cytopenias, lipid changes, and hepatic enzyme abnormalities, requiring tailored monitoring strategies for safe use.

Rinvoq (upadacitinib), is a selective JAK1 inhibitor approved for multiple inflammatory conditions. A lipid panel should be checked at baseline, after 12 weeks of treatment, and periodically thereafter due to observed increases in total cholesterol, LDL, and HDL levels. CBC monitoring should occur at baseline and periodically to assess for neutropenia, lymphopenia, and anemia. Liver enzymes should also be evaluated at baseline and periodically, as Rinvoq has been associated with hepatotoxicity. TB screening is mandatory at baseline and may be repeated during treatment depending on patient risk factors, as reactivation of latent TB has been reported in clinical trials and post-marketing data.

Cibinqo (abrocitinib), another selective JAK1 inhibitor, requires similar monitoring. Lipid panels should be obtained at baseline, at 12 weeks, and periodically thereafter due to dose-dependent risks of lipid elevations. CBC monitoring is essential at baseline and periodically to detect thrombocytopenia and neutropenia, which have been observed in clinical trials. Liver enzymes should also be assessed at baseline and periodically due to occasional hepatotoxicity. Baseline TB screening is required before initiating treatment, consistent with the risks seen in JAK inhibitors.

Olumiant (baricitinib), a JAK1 and JAK2 inhibitor, requires comprehensive monitoring due to its broader effects on cytokines that influence lipid metabolism and hematopoiesis. Lipid panels should be measured at baseline, after 12 weeks, and periodically, as increases in total cholesterol, LDL, and HDL levels have been consistently observed in trials. CBC monitoring is recommended at baseline and periodically due to risks of anemia, neutropenia, and lymphopenia. Liver enzymes should also be assessed at baseline and during treatment to monitor for hepatotoxicity. Renal function testing is critical at baseline and periodically, as Olumiant is partially renally cleared, and dose adjustments may be needed for patients with renal impairment. Baseline TB screening is required, with additional screening during therapy as indicated by risk.

Litfulo (ritlecitinib), a selective JAK3 and TEC-family kinase inhibitor, has a more targeted mechanism that avoids broader cytokine effects seen with JAK1 and JAK2 inhibition. Lipid monitoring is not necessary, as clinical trials did not show significant changes in cholesterol levels or lipid metabolism. However, baseline and periodic CBC assessments are recommended to monitor for lymphopenia and neutropenia, which have been reported. Liver enzyme testing should be conducted at baseline and periodically to detect mild hepatotoxicity. Baseline TB screening is required, as with other JAK inhibitors.

In summary, Rinvoq, Cibinqo, and Olumiant necessitate lipid monitoring at baseline, 12 weeks, and periodically, while Litfulo does not. All require baseline and periodic CBC and liver enzyme assessments, with additional considerations for renal function and TB screening based on the medication’s specific safety profile and patient risk factors.

I personally do baseline labs – CBC, CMP, lipid panel (except for Litfulo), and TB – for all JAKs and repeat initial labs (except TB), at 12 weeks, then again at 6 months. If no abnormalities or side effects are noted, I repeat once yearly, or request yearly labs from their primary care provider. If the patient is at high risk for contracting TB, I will repeat that yearly. That said, it is important to individualize monitoring strategies based on the patient’s comorbidities, concurrent medications, and any signs of adverse effects during treatment.