Background/Purpose: Secukinumab (SEC), a fully human monoclonal IgG1 antibody, provided rapid and significant improvements in all key clinical domains of psoriatic arthritis (PsA) in the FUTURE 1 study (NCT01392326) with improvements sustained through 3 years.¹ Here, we present the final 5 year efficacy and safety results of the study, including efficacy results in patients who had a dose escalation during the study.

Methods: Overall, 606 adults with active PsA were originally randomized to receive SEC IV→150 mg, IV→75 mg, or placebo) and then re-randomized to SEC 150 mg or 75 mg. The study design has been previously described.¹ At Wk 104, 460 patients entered the 3-year extension study. As per the protocol amendment, patients could have SEC dose escalated from 150 to 300mg and from 75 mg to 150/300mg from Wk 156, based on physician’s judgement. Assessments at Wk 260 included ACR20/50/70, PASI 90, HAQ-DI, SF-36 PCS, and resolution of dactylitis and enthesitis and are reported for patients originally randomized to the SEC 150 mg and 75 mg groups (observed data). Dose escalation results are reported for all patients who entered the extension study (i.e. including placebo-switchers). Safety is reported as exposure adjusted incidence rate/100 patient-years (EAIR) for all patients (n = 587) who received ≥1 dose of study treatment.

Results: Overall, 132/161 (82%) and 124/147 (84.4%) patients entered the extension study who were originally randomized to SEC 150 mg/75 mg, respectively, completed 260 Wks of treatment. Clinical responses were sustained or further improved through 5 years treatment (Table 1). A total of 86/236 (36.4%) patients on SEC 150 mg dose in extension were escalated to 300 mg, while 180/221 (81.4%) patients on SEC 75mg dose were escalated to 150/300mg. Post-escalation, the proportion of patients with non/low level ACR responses improved with corresponding increases in the proportion of patients achieving moderate/high ACR responses (Table 1). Over the entire study period (SEC mean exposure of 2320 patient-years), the safety profile of SEC was consistent with previous reports.¹ EAIR of selected adverse events for SEC were serious infections (1.8), ulcerative colitis (0.04), Crohn’s disease (0.1), and MACE (0.5). Six deaths (3 in each dose group) were reported in any SEC group through 5 years.

Conclusion: Over 80% of patients who entered the extension study completed 5 years of treatment. Secukinumab provided sustained improvements in the signs and symptoms in the major clinical domains of PsA through 5 years. Efficacy improved with dose escalation to secukinumab 150 mg or 300 mg during the study. Secukinumab was well tolerated with no new safety signals identified and safety profile was consistent with that previously reported.

Reference: 1. Mease PJ, et al. Ann. Rheum. Dis. 2017; 76 (suppl 2): 952.