In this interim analysis, 320 patients with moderate-to-severe AD were analyzed. Of these, 88 patients were in the baricitinib treatment cohort and 232 patients in the OOS treatment cohort, which included 53.0% patients (n = 123) treated with conventional systemics (of the n = 123 patients receiving conventional systemics, 69.9% [n = 86] received cyclosporine and 25.2% [n = 31] received methotrexate), 39.7% of patients (n = 92) treated with other oral JAKis (14.7% of patients [n = 34] treated with abrocitinib and 25.0% of patients [n = 58] treated with upadacitinib), 5.2% of patients (n = 12) treated with systemic corticosteroids and 2.2% of patients (n = 5) treated with OOS. The enrollment of patients across the different countries was consistent; 29.7% of patients (n = 95) enrolled from the UK, 25.0% of patients (n = 80) from Germany, 22.8% of patients (n = 73) from France and 22.5% of patients (n = 72) from Spain. The average age of the overall study population was 35.2 (SD = 13.6) years with treatment cohorts averages ranging from 30.0 (SD = 10.4) to 38.4 (SD = 15.8) years. However, patients in the baricitinib cohort were slightly older (38.4 years). About 50.9% (n = 163) of patients were females, with most female patients (59.1%) being treated with baricitinib. Disease duration was consistent across treatment cohorts, ranging between 25.0 (SD = 11.3) to 28.6 (SD = 11.6) years. For the overall population, 59.7% (n = 191) were exposed to systemic treatment at baseline. Of those patients treated with systemic medications, dupilumab and cyclosporine were the most commonly used (24.7%, n = 79 for both). Patients who received baricitinib (n = 40, 45.5%), upadacitinib (n = 28, 48.3%) and abrocitinib (n = 14, 41.2%) reported numerically more failures to prior systemic therapies at baseline (Table 1). There were 185 patients (57.8%) in the overall population who received monotherapy, and 135 patients (42.2%) received concomitant topical steroid use at baseline. As expected, 46.6% (n = 149) of the overall population had atopic comorbidities.

Mean BSA at baseline for the overall study population was 36.1 (SD = 24.4), with 219 (68.4%) of patients reporting BSA ≤ 40%. Mean BSA was 27.9 (SD = 19.7) for patients treated with baricitinib, 43.3 (SD = 25.3) for patients treated with conventional systemics, 34.7 (SD = 23.1) for patients treated with abrocitinib, 34.5 (SD = 25.8) for patients treated with upadacitinib, 35.9 (SD = 31.3) for patients treated with systemic corticosteroids and 33.3 (SD = 25.9) for patients treated with OOS (Table 2). For the overall study population, specific body region involvement was most prevalent in the upper extremities (n = 289, 90.3%) and in the face and neck (n = 286, 89.4%), with patients in the baricitinib cohort reporting the highest percentage of face/neck involvement (n = 82, 93.2%). Mean EASI at baseline for the overall study population was 18.2 (SD = 11.8). Mean EASI was 16.9 (SD = 11.7) for patients treated with baricitinib, 20.2 (SD = 12.7) for patients treated with conventional systemics, 15.0 (SD = 7.6) for patients treated with abrocitinib, 17.9 (SD = 11.3) for patients treated with upadacitinib, 17.9 (SD = 15.3) for patients treated with systemic corticosteroids and 15.0 (SD = 9.4) for patients treated with OOS. However, the EASI scores reported were within the moderate range for all cohorts. The overall proportion of patients with vIGA-AD 4 (severe) was 32.2% (n = 99); these patients also reported a mean POEM score of 17.5 (SD = 8.8), which was in the severe range as well. Mean Itch NRS at baseline for the overall study population was 6.5 (SD = 3.9); the Itch NRS scores for all treatments ranged from 5.9 (SD = 2.2) to 7.4 (SD = 1.9).

The 320 participants enrolled in the study were stratified into subgroups by BSA (≤ 40% and > 40%) and Itch NRS (< 7 and ≥ 7) at baseline. A total of 108 patients were in the BSA ≤ 40%/Itch NRS ≥ 7 subgroup, 111 in the BSA ≤ 40%/Itch NRS < 7, 57 in the BSA > 40%/Itch NRS ≥ 7 and 44 in the BSA > 40%/Itch NRS < 7 subgroup. At baseline, the average age for the subgroups ranged between 33.1 (SD = 12.5) and 40.5 (SD = 16.7) years. Disease duration was consistent across the subgroups ranging from 24.9 (SD = 12.4) and 29.7 (SD = 17.1). Patients with BSA ≤ 40% were more systemic experienced than patients with BSA > 40% at baseline. Across all subgroups, the most common AD treatments reported prior to baseline were cyclosporine and dupilumab (n = 79, 24.7% for both). Patients in the BSA ≤ 40%/Itch NRS ≥ 7 subgroup reported a numerically higher number of failures to previous systemics (Supplemental Table 1). Despite patients with BSA ≤ 40%/Itch NRS ≥ 7 who had mean BSA and EASI scores of 22.9 and 15.0, respectively, which fell within the moderate range, they reported high DLQI (15.1) and POEM (17.6) scores, indicating high disease burden which may be associated with the severe itch (mean NRS 8.2) they experienced (Supplemental Table 2). Patients in the BSA ≤ 40%/Itch NRS ≥ 7 subgroup mostly reported upper extremities (n = 99, 91.7%) and face/neck (n = 96, 88.9%) as the specific body regions affected with AD. The disease involvement experienced by these patients is reflected in the vIGA-AD scores reported; most patients within the BSA ≤ 40% and Itch NRS ≥ 7 reported scores of 3 (n = 61, 58.7%) and 4 (n = 29, 27.9%), which were in the moderate-to-severe range. Patients with BSA ≤ 40% were the predominant group, and the subgroup BSA ≤ 40%/Itch NRS ≥ 7 was mostly treated with JAKis (63.9% of patients). From the patients treated with abrocitinib, baricitinib and upadacitinib, 50.0%, 38.6% and 31.0% had BSA ≤ 40%/Itch NRS ≥ 7 at baseline, respectively (Fig. 1).

Atopic disease severity for all treatment cohorts at baseline. Data reported as percentage (number). Conventional systemics included azathioprine, azathioprine + prednisone, cyclosporine, cyclosporine + prednisolone, methotrexate, methotrexate + prednisolone, mycophenolate mofetil; systemic corticosteroids included betamethasone, dexamethasone, methylprednisolone, prednisolone, prednisone, triamcinolone, other systemic corticosteroids; other oral JAKis included abrocitinib and upadacitinib; other included OOS AD treatments according to country-specific guidelines