Clinical outcomes following switch from risankizumab to guselkumab in Crohn’s disease: a real-world case series

BACKGROUND: Risankizumab is an interleukin (IL)-23 inhibitor that is effective for the treatment of moderate-to-severe Crohn's disease (CD). However, many patients experience loss of response. Switching within the IL-23 inhibitor class to agents with more frequent dosing, such as guselkumab, may represent a salvage strategy, though no supporting data exist. We aimed to describe outcomes following switching between IL-23 antagonists. METHODS: This case series included five CD patients at a Canadian tertiary care center with primary non-response or secondary loss of response to risankizumab who were switched to guselkumab. Data were collected at baseline, during risankizumab therapy, and after switching. RESULTS: Five CD patients with inadequate response to risankizumab were included. One patient (20%) had primary non-response and four (80%) had secondary loss of response. Risankizumab duration ranged from 3 to 38 months (mean 17.4 ± 12.9). Four patients had active disease on baseline endoscopy before switching. Mean follow-up after switching was 3.8 ± 1.9 months. Mean CD-PRO2 improved from 22.7 to 5.2 post-switching. Clinical response (≥50% CD-PRO2 reduction) was achieved in 4/5 patients (80%), and clinical remission (CD-PRO2 < 8) was similarly achieved in 4/5 patients (80%). Among four patients with biochemical data, biochemical response (≥50% reduction in fecal calprotectin [FCal]) and remission (normalization of FCal) each occurred in 75%, with a mean FCal reduction of 618 µg/g. One patient had biochemical worsening despite clinical improvement. No safety concerns were reported. CONCLUSION: In CD patients with loss of response to risankizumab, switching to guselkumab may be effective in selected patients. Larger confirmatory studies are needed.