Long-term efficacy and safety of baricitinib in patients with severe alopecia areata: 104-week results from BRAVE-AA1 and BRAVE-AA2.

BACKGROUND: Efficacy of the Janus kinase (JAK) inhibitor baricitinib for severe alopecia areata (AA) continuously increased over 52 weeks in two Phase 3 trials. There are limited long-term data on JAK inhibitors in AA. OBJECTIVES: To evaluate efficacy and safety of baricitinib for severe AA through 104 weeks of continuous therapy. METHODS: Integrated data from the BRAVE-AA1 and BRAVE-AA2 Phase 3 trials included adults with Severity of Alopecia Tool (SALT) scores ≥50 (≥50% scalp hair loss) randomized to and continuously treated with 2-mg or 4-mg baricitinib through Week 104. Patients who qualified to remain on continuous treatment included subjects who achieved SALT score ≤20 at Week 52 (Week-52 responders; 2-mg: N = 65; 4-mg: N = 129) and baricitinib 4-mg-treated patients who had SALT score >20 at Week 52 but achieved SALT score ≤20 at prior visit(s) and/or had significant improvement in eyebrow or eyelash hair growth relative to baseline by Week 52 (Week-52 mixed responders; N = 110). Week-104 outcomes included the proportion of patients achieving SALT score ≤20 (≤20% scalp hair loss). Data were censored after treatment discontinuation. RESULTS: Among baricitinib 4-mg-treated and baricitinib 2-mg-treated Week-52 responders, 90.7% and 89.2%, respectively, maintained SALT score ≤20 at Week 104. Among Week-52 mixed responders, 39.1% reached SALT score ≤20 by Week 104. Continued improvement in eyebrow and eyelash regrowth was observed across groups. The most frequent treatment-emergent adverse events were COVID-19, upper respiratory tract infection, headache, nasopharyngitis, acne, urinary tract infection and creatine phosphokinase increase. CONCLUSIONS: Baricitinib demonstrated a high level of maintenance of efficacy over 104 weeks in patients with severe AA. Efficacy increased in Week-52 mixed responders, illustrating that long-term treatment is necessary to observe maximum benefit in some patients. No new safety signals were observed.

Pooled safety analysis of baricitinib in adult patients with atopic dermatitis from 8 randomized clinical trials.

BACKGROUND: Janus kinase (JAK) inhibition is a new mode of action in atopic dermatitis (AD); clarity about drug class safety considerations in the context of AD is important. Baricitinib, an oral, reversible, selective inhibitor of JAK1/JAK2, is in late-stage development for adult patients with moderate-to-severe AD. OBJECTIVE: To report pooled safety data for baricitinib in patients with moderate-to-severe AD in the clinical development program including long-term extension (LTE) studies. METHODS: This analysis included patient-level safety data from six double-blinded, randomized, placebo-controlled studies (one phase 2 and five phase 3), one double-blinded, randomized, LTE study and one open-label LTE study, reported in three data sets: placebo-controlled, 2-mg - 4-mg extended and All-bari AD. Safety outcomes include treatment-emergent adverse events, adverse events of special interest and abnormal laboratory changes. Proportions of patients with events and incidence rates were calculated. RESULTS: Data were collected for 2531 patients who were given baricitinib for 2247 patient-years (median duration 310 days). The frequency of serious infections, opportunistic infections and conjunctival disorders was low and similar between treatment groups in the placebo-controlled period. The most common serious infections were eczema herpeticum [n = 11, incidence rates (IR) = 0.5], cellulitis (n = 6, IR = 0.3) and pneumonia (n = 3, IR = 0.1). There were four opportunistic infections (IR = 0.2). No malignancies, gastrointestinal perforations, positively adjudicated cardiovascular events or tuberculosis were reported in the placebo-controlled period in baricitinib-treated patients. Frequency of herpes simplex was higher in the 4-mg group (6.1%) vs. the 2-mg (3.6%) and placebo group (2.7%); IRs in the extended data set (2-mg IR = 9.6; 4-mg IR = 14.5) were lower vs. the placebo-controlled data set (2-mg IR = 12.4; 4-mg IR = 21.3). In the All-bari AD data set, there were two positively adjudicated major adverse cardiovascular events (2-mg group): two venous thrombosis events (4-mg group) and one death. CONCLUSION: This integrated safety analysis in patients with moderate-to-severe AD confirms the established safety profile of baricitinib.

Brain serotonin deficiency leads to social communication deficits in mice.

A deficit in brain serotonin is thought to be associated with deteriorated stress coping behaviour, affective disorders and exaggerated violence. We challenged this hypothesis in mice with a brain-specific serotonin depletion caused by a tryptophan hydroxylase 2 (TPH2) deficiency. We tested TPH2-deficient (Tph2(-/-)) animals in two social situations. As juveniles, Tph2(-/-) mice displayed reduced social contacts, whereas ultrasonic vocalizations (USVs) were unchanged within same-sex same-genotype pairings. Interestingly, juvenile females vocalized more than males across genotypes. Sexually naive adult males were exposed to fresh male or female urine, followed by an interaction with a conspecific, and re-exposed to urine. Although Tph2(-/-) mice showed normal sexual preference, they were hyper-aggressive towards their interaction partners and did not vocalize in response to sexual cues. These results highlight that central serotonin is essential for prosocial behaviour, especially USV production in adulthood, but not for sexual preference.