LB972 IL-17 inhibitor-induced remission of guttate psoriasis

Abstract

Effective, targeted treatments for guttate psoriasis are lacking. Drugs that block the interleukin-17 (IL-17) pathway are highly effective in the treatment of plaque psoriasis. Given the overlap of immunopathogenic features between guttate and plaque psoriasis, including an over activation of Th17 cells, it is plausible that IL-17A inhibition would be an effective treatment for guttate psoriasis. Ixekizumab, a humanized IgG4 monoclonal antibody that targets interleukin-17A (IL-17A) is FDA-approved for the treatment of moderate-to-severe plaque psoriasis in adult patients who are candidates for systemic therapy, but to our knowledge has never been reported in the treatment of guttate psoriasis. Here we report three cases of guttate psoriasis successfully treated with ixekizumab. Three patients presented with guttate psoriasis involving 15-40% body surface area (BSA) and with psoriasis physician global assessment (PGA) scores ranging from 3-6. Two patients developed lesions idiopathically, and one developed lesions after a documented episode of streptococcal pharyngitis. Lesions had been present for 7-90 days at the time of presentation, and prior ineffective treatment attempts across patients by primary care providers included courses of keflex, triamcinolone cream, betamethasone ointment, oral prednisone, oral acyclovir, and expectant management. Patients were treated with standard ixekizumab dosing regimens for plaque psoriasis. Starting doses of 160mg subcutaneous injection and induction doses of 80mg every two weeks thereafter were given. Two patients achieved complete clearance after 2 doses of ixekizumab (clearance documented in clinic at 42 and 86 days after treatment initiation), and the third achieved 1% BSA involvement and PGA score of 1 after 3 doses (documented 61 days after treatment initiation). No adverse effects of treatment were noted. This report provides strong evidence for the potential efficacy of IL-17 inhibition in guttate psoriasis. Additional follow-up to assess for duration of clinical remission and progression to plaque psoriasis, as well as larger, randomized, controlled studies are needed.