Efficacy and Safety of Guselkumab for Ulcerative Colitis Through Week 92 of the QUASAR Long-Term Extension Study

We evaluated guselkumab efficacy and safety through week 92 of the ongoing QUASAR (NCT04033445) long-term extension (LTE).

Intravenous guselkumab induction responders were randomized (1:1:1) at QUASAR maintenance study week 0 (M-0) to receive subcutaneous guselkumab 100 mg every 8 weeks (q8w) or 200 mg every 4 weeks (q4w) or placebo. Participants completing the maintenance week 44 (M-44) visit could enter the LTE, continuing the treatment they were receiving. Participants receiving placebo discontinued at unblinding after week M-44 analyses and were excluded from LTE efficacy analyses. Clinical remission at week M-92 was a key efficacy endpoint. Safety was evaluated from weeks M-44 through M-92.

Overall, 87% (329/378) of participants randomized to guselkumab at week M-0 entered the LTE. Among the 303 participants who had not received a maintenance dose adjustment (guselkumab 100 mg q8w, n = 155; guselkumab 200 mg q4w, n = 148), 95% (287/303) completed treatment through week M-92. At week M-92, among participants receiving guselkumab 100 mg q8w or 200 mg q4w, 71% (110/155) and 74% (109/148), respectively, achieved clinical remission (analyzed using nonresponder imputation). Among participants receiving guselkumab 100 mg q8w or 200 mg q4w with available data at week M-92 (as observed analysis), 75% (110/147) and 83% (109/132), respectively, achieved clinical remission. Nearly 100% (218/219) of participants in clinical remission at week M-92 were corticosteroid free for ≥8 weeks prior. Safety findings were consistent with the known safety profile.

Sustained and durable corticosteroid-free efficacy and safety were observed among participants receiving up to 2 years of guselkumab maintenance treatment.