No Risk Increase for VTE in 6 Months of Baricitinib Therapy for Alopecia Areata

Individuals with alopecia areata who are candidates for baricitinib treatment are not at an increased risk of developing venous thromboembolism (VTE), according to recent findings.1

These data were the conclusion of a recent observational study conducted by such investigators as Giacomo Caldarola, MD, PhD, from the Dipartimento di Scienze Mediche e Chirurgiche at the Fondazione Policlinico Universitario A. Gemelli—IRCCS in Rome. Caldarola and colleagues wrote that there had been an alart on VTE risk issued in January 2023 by the European Medicines Agency (EMA) which was linked to the use of Janus kinase inhibitors (JAKi) in chronic inflammatory diseases.2

This had been based on post-marketing data from individuals living with rheumatoid arthritis who were treated with tofacitinib. Nevertheless, they highlighted that JAKi vary in their enzyme selectivity and thus in their impacts on patients.

“The present study aimed: (1) to investigate VTE risk factors in a cohort of patients with alopecia areata (AA) eligible for baricitinib therapy and (2) to assess any change in laboratory VTE markers after 6 months of baricitinib treatment,” Caldarola and colleagues wrote.1

Trial Design and Findings on Baricitinib

The investigative team's prospective observational study was carried out in the timeframe between July 2023 - July 2024. They involved adults ≥18 years who were living with moderate-to-severe alopecia areata. These subjects were also noted as eligible for baricitinib 4 mg therapy and had consecutively presented at the team's department.

Baseline demographic and clinical data were recorded by Caldarola et al during their screening visits, and VTE risk was then evaluated via a detailed medical history assessment. The investigators highlighted major risk factors for VTE, 1 of which included reporting a prior VTE episode. They also highlighted minor risk factors, which comprised active malignancy, smoking history, a history of thrombophlebitis, recent trauma or fractures, family VTE history, implementation of estrogen–progestin contraceptives, recent major surgery, prolonged immobility, recurrent miscarriages, and smoking history.

Laboratory testing of these individuals at baseline included antiphospholipid antibodies, antithrombin III, protein S, protein C, homocysteine, and factor VIII. These markers were later reassessed by Caldarola and coauthors at the 6-month mark. Participants' genetic predisposition to VTE (prothrombin G20210A and factor V Leiden mutations) was also evaluated by the investigators at baseline. It was also noted that those who presented with either 1 major or at least 2 minor risk factors were ineligible for baricitinib.

Screening for the medication involved a total of 47 patients with moderate-to-severe alopecia areata, and these individuals were included in the study. Caldarola et al did not exclude any based on VTE contraindications. Over the course of the baricitinib treatment, there were no thrombotic events were reported.1 However, the investigative team did highlight that 4.2% of these subjects sustained bone fractures, a known VTE risk factor. Following 6 months of continuous therapy, the team's follow-up laboratory findings were available for 37 of the 47 participants.

No significant changes were observed by Caldarola and colleauges in most of the study's parameters, although they did highlight a statistically significant dip in patients' mean factor VIII levels. This reduction was from 119.1% at baseline to 101.8% at the 6-month mark (P = .019). Overall, the team concluded none of the participants developed VTE or demonstrated increased susceptibility to VTE during treatment.

Such findings were noted as being consistent with previous evidence from large-scale observational cohorts. In fact, the investigators noted that rather than raising risk markers, the use of baricitinib was linked with a notable decline in patients' factor VIII levels. This was noteworthy due to elevated factor VIII being considered a prothrombotic marker and given that it has been implicated in the heightened VTE risk observed among those with rheumatoid arthritis. This observation aligns with findings from the baricitinib alopecia areata clinical trial program, during which it was concluded that VTE incidence was low (0.10 per 100 patient-years).

Caldarola and colleagues highlighted the principal limitations of their study, noting the analysis's relatively small sample size and the limited duration of follow-up. Despite such limitations, the investigative team did still highlight its main strength as having been the first detailed assessment of VTE predisposition in individuals with alopecia areata treated with baricitinib.

“In conclusion, our findings suggest that patients who are candidates for baricitinib treatment can be reassured about the risk of developing VTE adverse events,” the investigators wrote.1 “We emphasize that, in clinical practice, comprehensive thrombosis screening is not routinely required before starting JAKi therapy, except in patients with specific clinical risk factors, such as a personal or family history of thrombotic events or recurrent miscarriages.”

References

1. G Caldarola, A Ferretti, LM Pinto, et al. No Increased Risk of Thromboembolic Events During 6-Month Treatment With Baricitinib in Patients With Alopecia Areata. International Journal of Dermatology (2025): 1–3, https://doi.org/10.1111/ijd.70051.

2. B King, M Ohyama, O Kwon, et al. Two Phase 3 Trials of Baricitinib for Alopecia Areata. New England Journal of Medicine 386, no. 18 (2022): 1687–1699, https://doi.org/10.1056/NEJMoa2110343.