O13 Impact of amlitelimab (an anti-OX40 ligand antibody) on atopic dermatitis by body region: post hoc results from the STREAM-AD phase IIb study of moderate-to-severe atopic dermatitis

Abstract Amlitelimab is a fully human, nondepleting anti-OX40 ligand (OX40L) monoclonal antibody under investigation for atopic dermatitis (AD). Lesions on the head and neck are difficult to treat due to multiple triggers and generally have lower response to treatments than lesions observed in other body regions. Here we report the impact of amlitelimab on Eczema Area and Severity Index (EASI) subscores in different body regions from the STREAM-AD trial. STREAM-AD (NCT05131477) is a randomized, double-blind, placebo-controlled, phase IIb trial. In part 1, adult participants with moderate-to-severe AD were randomized (1 : 1 : 1 : 1 : 1) to subcutaneous amlitelimab (250 mg with 500 mg loading dose, n = 77; 250 mg, n = 78; 125 mg, n = 77; 62.5 mg, n = 79) or placebo (n = 79) every 4 weeks. The primary endpoint, percentage change in EASI score at week 16, was met. In this post hoc analysis, EASI subscores using least-squares mean percentage change from baseline were assessed at week 24. Data on or after treatment discontinuation or use of rescue or prohibited medications were considered missing and were imputed by worst observation carried forward. At week 24, all amlitelimab doses showed improvement in EASI subscores compared with placebo across all body regions, including in the difficult-to-treat head and neck region (Table). Across all regions, the highest response was seen with 250 mg + loading dose. Amlitelimab improved EASI subscores across all AD signs and body locations at week 24. The data suggest that amlitelimab may address the heterogeneous clinical presentation of moderate-to-severe AD, especially for hard-to-treat body regions such as the head and neck area and lesions.TableLeast-squares mean percentage change from baseline (%ΔBL) in Eczema Area and Severity Index subscores by body regionLeast-squares mean %ΔBL (SE)Amlitelimab (Q4W)Placebo (Q4W)250 mg + LD250 mg125 mg62.5 mgNumber7778777979Head and neck Erythema−62.1 (6.04)−55.1 (6.23)−54.2 (5.82)−47.1 (6.01)−24.5 (6.45) Oedema/papulation−65.6 (6.35)−60.4 (6.64)−62.0 (6.18)−50.0 (6.39)−29.8 (6.77) Excoriation−75.3 (6.91)−70.5 (6.90)−66.8 (6.76)−59.5 (6.89)−29.3 (7.43) Lichenification−72.0 (6.47)−65.0 (6.73)−61.0 (6.21)−52.5 (6.48)−29.4 (6.91)Trunk Erythema−63.5 (5.07)−62.0 (5.18)−57.2 (4.99)−51.7 (5.05)−29.4 (5.36) Oedema/papulation−58.7 (5.87)−63.0 (5.99)−54.1 (5.78)−47.3 (5.84)−23.3 (6.18) Excoriation−69.5 (5.90)−64.0 (6.08)−68.8 (5.89)−62.3 (5.93)−34.3 (6.25) Lichenification−71.2 (5.88)−61.4 (6.09)−66.9 (5.82)−53.8 (6.00)−31.7 (6.24)Upper extremities Erythema−53.6 (4.91)−47.5 (4.96)−49.5 (4.77)−49.1 (4.88)−30.1 (5.18) Oedema/papulation−55.4 (5.34)−55.3 (5.47)−52.0 (5.22)−48.8 (5.34)−31.7 (5.68) Excoriation−63.2 (5.50)−60.3 (5.45)−62.0 (5.35)−55.6 (5.40)−34.4 (5.77) Lichenification−60.8 (5.20)−52.1 (5.21)−51.4 (5.02)−46.4 (5.16)−28.9 (5.41)Lower extremities Erythema−58.21 (5.63)−54.11 (5.88)−58.98 (5.47)−55.20 (5.59)−36.08 (5.92) Oedema/papulation−63.05 (5.74)−58.56 (5.94)−60.04 (5.55)−51.09 (5.67)−38.96 (5.97) Excoriation−63.00 (5.96)−59.43 (6.10)−60.62 (5.83)−59.67 (5.83)−40.56 (6.23) Lichenification−66.29 (5.65)−57.45 (5.91)−59.27 (5.61)−55.26 (5.72)−34.84 (6.02)Nominal P < 0.05 for all amlitelimab dose arms vs. placebo (no multiplicity adjustment). LD, loading dose; Q4W, every 4 weeks.