Baricitinib Use in Alopecia Areata Patients

Introduction to Baricitinib Therapy

The British Journal of Dermatology suggests that baricitinib is safe and effective for treating severe alopecia areata, even in patients with genetic susceptibility to JAK2 mutations, due to its distinct therapeutic mechanism of JAK1/JAK2 inhibition for immune modulation 1

Oncogenic JAK2 mutations, such as JAK2 V617F, cause myeloproliferative neoplasms and are treated with JAK2 inhibitors like ruxolitinib, highlighting the difference between therapeutic JAK2 inhibition and oncogenic JAK2 mutations 1
Treating immune-mediated inflammatory diseases with JAK inhibitors may be associated with a low risk of lymphoma or solid tumor development 1

Baricitinib preferentially inhibits both JAK-1 and JAK-2, making it effective for alopecia areata, as noted by the Journal of the American Academy of Dermatology 2, 3

Despite boxed warnings for increased malignancy risk across the JAK inhibitor class, the actual risk in alopecia areata patients is low, with an incidence rate of malignancies (except nonmelanoma skin cancer) of 0.22/100 patient-years versus 0.66/100 patient-years in the placebo group, according to the British Journal of Dermatology 1, 4

The British Journal of Dermatology recommends screening for hepatitis B, hepatitis C, tuberculosis, and pregnancy before starting baricitinib, as well as checking complete blood count with differential, liver enzymes, and renal function 2, 3
Patients should be assessed for VTE risk factors and considered for malignancy screening, particularly those aged ≥53 years, as suggested by the British Journal of Dermatology 1, 4, 5
The Journal of the American Academy of Dermatology advises administering recombinant zoster vaccine (Shingrix) before initiating treatment with baricitinib 2, 6
For patients with renal impairment (eGFR <30 mL/min), baricitinib is not recommended, according to the British Journal of Dermatology 4, 5
No dose adjustment is needed for mild-to-moderate hepatic impairment (Child-Pugh A/B), as noted by the British Journal of Dermatology 4, 5

The Journal of the American Academy of Dermatology and Arthritis and Rheumatology recommend monitoring CBC with differential and comprehensive metabolic panel at baseline, 4-8 weeks after starting, then every 3 months, as well as lipids at baseline, 4-8 weeks after starting, then annually 2, 3, 7
Patients should be monitored for signs of infection, particularly herpes zoster, and counseled on warning signs of VTE, according to the Journal of the American Academy of Dermatology and British Journal of Dermatology 2, 5, 6