What monitoring investigations can be used to follow up on a patient with atopic dermatitis taking JAK2 (Janus kinase 2) inhibitors for thrombosis risk?

From the Guidelines

Patients with atopic dermatitis taking JAK2 inhibitors should be monitored for thrombosis risk using routine laboratory tests, including complete blood counts and platelet counts.

Monitoring Investigations

• Complete blood counts (CBC) to monitor for changes in platelet counts, as JAK inhibitors may modulate the JAK2 receptor involved in myelopoiesis and platelet production 1
• Platelet counts to detect any transient increases in platelet counts following JAK inhibitor therapy initiation, although these may not be predictive of VTE 1

Guidance on Monitoring

The International Eczema Council provides a practical guide to using oral JAK inhibitors for atopic dermatitis, including recommendations for laboratory monitoring 1. While the exact monitoring schedule may vary depending on the specific JAK inhibitor used, a sensible approach to prescribing these drugs includes regular monitoring of laboratory parameters to detect potential thrombotic events 1. However, the current evidence does not support a significantly increased risk of VTE with JAK inhibitors, with a pooled incidence rate ratio of 0.68 (95% CI 0.36-1.29) for VTE 1. Therefore, monitoring should be guided by the individual patient's risk factors and the specific JAK inhibitor used, rather than a one-size-fits-all approach.

From the FDA Drug Label

Thromboembolic events were observed in clinical trials with OPZELURA. Thrombosis, including deep vein thrombosis (DVT), pulmonary embolism (PE), and arterial thrombosis have been reported in patients receiving JAK inhibitors used to treat inflammatory conditions. If symptoms of thrombosis occur, discontinue OPZELURA and evaluate and treat patients appropriately.

The monitoring investigations that can be used to follow up on a patient with atopic dermatitis taking JAK2 inhibitors for thrombosis risk include:

• Evaluating patients for symptoms of thrombosis, such as deep vein thrombosis (DVT), pulmonary embolism (PE), and arterial thrombosis.
• Discontinuing OPZELURA if symptoms of thrombosis occur and evaluating and treating patients appropriately. 2

From the Research

Monitoring Investigations for Thrombosis Risk

To follow up on a patient with atopic dermatitis taking JAK2 (Janus kinase 2) inhibitors for thrombosis risk, the following monitoring investigations can be considered:

• Laboratory tests to monitor for signs of thrombosis, such as D-dimer levels and complete blood counts 3
• Regular assessment of platelet counts, as decreased platelet counts have been reported as a treatment-emergent adverse event with oral JAK inhibitor use 4
• Monitoring for signs and symptoms of venous thromboembolism (VTE), such as deep vein thrombosis and pulmonary embolism 3

Risk of Venous Thromboembolism

The risk of VTE associated with atopic dermatitis and treatment with JAK inhibitors is unclear, but a systematic review and meta-analysis found no significant association between AD and incident VTE, and no increased risk of VTE associated with treatment with JAK inhibitors 3

• The incidence rate of VTE was 0.15 and 0.12 events per 100 patient-years in participants with AD receiving JAK inhibitors and placebo, respectively 3

Safety and Efficacy of JAK Inhibitors

JAK inhibitors have been shown to be effective and safe for the treatment of atopic dermatitis, with significant improvements in Eczema Area and Severity Index (EASI) score and Investigator's Global Assessment (IGA) response 5

• However, JAK inhibitors can lead to laboratory anomalies and rare serious adverse events, such as herpes zoster and decreased platelet counts 4, 6