Inhibition of radiographic progression across levels of composite index-defined disease activity in patients with active psoriatic arthritis treated with intravenous golimumab: results from a phase-3, double-blind, placebo-controlled trial

Background In the GO-VIBRANT trial of intravenous golimumab in psoriatic arthritis (PsA), golimumab significantly inhibited radiographic progression. In post hoc analyses, we evaluated changes in total PsA-modified Sharp/van der Heijde scores (SHS) across levels of composite index-defined disease activity following treatment. Methods In this phase-3, double-blind, placebo-controlled trial, 480 bio-naive patients with active PsA randomly received intravenous golimumab 2 mg/kg (N = 241; week 0, week 4, every 8 weeks [q8w]) or placebo (N = 239; week 0, week 4, week 12, week 20) followed by golimumab (week 24, week 28, q8w) through week 52. Week 24 and week 52 SHS changes in patient subgroups, defined by levels of disease activity as assessed by several composite measures (minimal disease activity [MDA], very low disease activity [VLDA], Psoriatic ArthritiS Disease Activity Score [PASDAS], Disease Activity in Psoriatic Arthritis [DAPsA], Clinical Disease Activity Index [CDAI]), were evaluated post hoc in 474 patients with evaluable radiographic data. Partially (last-observation-carried-forward methodology) and completely (nonresponder methodology) missing data were imputed. Results Across indices, golimumab-treated patients demonstrated less radiographic progression than placebo-treated patients, regardless of disease activity state achieved via golimumab, from week 0 to 24 (e.g., mean changes in PsA-modified SHS were - 0.83 vs. 0.91, respectively, in patients achieving MDA and - 0.05 vs. 1.49, respectively, in those not achieving MDA). Treatment differences observed at week 24 persisted through week 52, despite placebo-randomized patients crossing over to golimumab at week 24 (e.g., mean changes in PsA-modified SHS from week 0 to 52 for golimumab- vs. placebo -> golimumab-treated patients achieving MDA were - 1.16 vs. 1.19, respectively) and regardless of whether low disease activity was achieved (0.03 vs. 1.50, respectively, in those not achieving MDA). Consistent patterns were observed for disease activity assessed using VLDA, PASDAS, DAPsA, and CDAI composite endpoints. Conclusions The extent of structural damage inhibition afforded by up to 1 year of intravenous golimumab treatment paralleled levels of PsA activity, with greater progression of structural damage observed in patients with sustained higher disease activity. Among patients not achieving low levels of disease activity across several composite indices, golimumab-randomized patients appeared to exhibit far less progression of structural damage than placebo-randomized PsA patients, illustrating a potential disconnect between responses, wherein golimumab can inhibit structural damage independent of clinical effect.