Efficacy of secukinumab without the initial weekly loading dose in patients with chronic plaque psoriasis

BACKGROUND: Secukinumab is administered at the labelled dose of 300 mg at weeks 0, 1, 2, 3, 4 (loading dose) and every 4 weeks thereafter. OBJECTIVES: To investigate the efficacy of secukinumab administered without the initial loading dose in patients with psoriasis. METHODS: This was a retrospective observational study including adult patients with psoriasis (n = 156) treated with secukinumab 300 mg administered either according to the labelled dose (n = 75) or without the initial loading dose (n = 81). Efficacy was evaluated by comparing the Psoriasis Area and Severity Index (PASI) 75 and PASI 90 response rates at week 8, 12, 16, 32 and 48. RESULTS: For patients who received the labelled dose vs. those who did not, PASI 75 response rates were achieved at week 8, 12, 16, 32 and 48 by 60% vs. 40% (P < 0·01), 72% vs. 61% (P < 0·01), 77% vs. 75%, 85% vs. 77% and 79% vs. 78%, respectively. PASI 90 responses were achieved at the same time points by 45% vs. 31% (P < 0·01), 49% vs. 40% (P < 0·01), 54% vs. 47%, 55% vs. 47% and 57% vs. 54% for those who received the labelled dose vs. those who did not, respectively. A greater proportion of patients receiving secukinumab without the loading dose discontinued treatment because of inefficacy (25% vs. 13%, P < 0·05), particularly those with body weight greater than 80 kg. CONCLUSIONS: Secukinumab administered without the loading dose is associated with a higher proportion of primary inefficacy, and achieved inferior results compared with the labelled dose at week 8 and week 12, but showed similar efficacy thereafter. What's already known about this topic? Secukinumab is an interleukin (IL)-17A inhibitor for chronic plaque psoriasis administered by subcutaneous injections at the labelled dose of 300 mg at weeks 0, 1, 2, 3, 4 (loading dose) and every 4 weeks thereafter (maintenance dose). Dose adjustment is common in clinical practice, and can consist of dose reduction when a prolonged remission is obtained or a dose increase in order to improve efficacy. What does this study add? The efficacy of secukinumab administered without the initial weekly loading dose was significantly inferior compared with the labelled dose in the short term, but was similar after week 16 and up to week 48. A greater proportion of patients receiving secukinumab without the loading dose showed primary inefficacy, particularly those with body weight greater than 80 kg.