Narrowband-UVB may restore adalimumab efficacy in chronic plaque psoriasis patients: A prospective exploratory cohort...

Biologic therapies (BT) have revolutionized psoriasis management, yet secondary treatment failure remains a significant challenge. Narrowband ultraviolet B (NB-UVB) phototherapy is an established treatment with local immunomodulatory effects that may synergize with BT to restore efficacy. Evidence supporting this approach, particularly regarding adalimumab failure, is limited. In this prospective, exploratory cohort study, 11 adults with chronic plaque psoriasis exhibiting secondary loss of response to adalimumab (without anti-adalimumab antibodies) underwent adjunctive NB-UVB phototherapy three times weekly for 25-30 sessions, while continuing adalimumab 40 mg biweekly. Disease severity was assessed using the Psoriasis Area and Severity Index (PASI). Clinical response was defined as ≥ 50% PASI reduction from flare or return to baseline PASI. Mean PASI increased from 4.1 ± 0.7 at baseline to 11.8 ± 1.6 at flare. Following NB-UVB, mean PASI decreased to 6.2 ± 3.2 (p = 0.006). Excluding non-responders, PASI was 4.0 ± 0.5, comparable to pre-flare values. Five patients (45,5%) achieved PASI 50, two of whom (18.2%) achieved PASI 75. Responses were sustained for at least 24 months. DLQI improved from 14.7 ± 2.4 at flare to 5.6 ± 6.2 after NB-UVB (p = 0.005), indicating a substantial reduction in disease burden. NB-UVB was well tolerated, with no significant adverse events. Three non-responders switched to ustekinumab. Adjunctive NB-UVB phototherapy restored adalimumab efficacy in a majority of patients experiencing secondary failure, offering a safe, accessible, and cost-conscious strategy. Larger controlled studies are warranted to confirm efficacy, elucidate mechanisms, and define the role of combination therapy in modern psoriasis management.