J Crohns Colitis. 2024 May 31;18(5):679-685. doi: 10.1093/ecco-jcc/jjad188.

Xavier Roblin ¹, Stéphane Nancey ², Konstantinos Papamichael ³, Gérard Duru ¹, Mathurin Flamand ⁴, Sandy Kwiatek ⁵, Adam Cheifetz ³, Nicole Fabien ⁶, Mathilde Barrau ¹, Stéphane Paul ⁷

Author information

¹Department of Gastroenterology, University Hospital of Saint-Etienne, Saint-Etienne, France.

²Department of Gastroenterology, Lyon Sud hospital, Hospices Civils de Lyon, University Claude Bernard Lyon 1, Lyon, France.

³Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.

⁴Clinique gastroentérologique Nantes, Nantes, France.

⁵Service gastroentérologie CHU Saint Pierre Ile de la reunion, Saint Pierre, Reunion.

⁶Department of immunology University Claude Bernard, Lyon, France.

⁷Immunology laboratory, CIC1408, University Hospital of Saint-Etienne, Saint-Etienne, France., CIRI [Centre International de Recherche en Infectiologie], Université Claude Bernard Lyon 1, INSERM U1111, CNRS, UMR5308, ENS Lyon, Université Jean Monnet de Saint-Etienne, France.

Abstract

Background: The relationship between subcutaneous infliximab [SC-IFX] concentrations and favourable therapeutic outcomes in patients with Crohn's disease [CD] and ulcerative colitis [UC] remains elusive.

Patients and methods: This cross-sectional study included consecutive adult patients with inflammatory bowel disease [IBD] treated with SC-IFX at a maintenance dose of 120 mg/2 weeks. Investigated therapeutic outcomes included sustained clinical remission; composite clinical and biomarker remission [clinical remission and C-reactive protein <5 mg/L]; biochemical remission [faecal calprotectin <250 µg/g]; and deep remission [clinical, biological, and biochemical remission].

Results: Of 91 patients identified, 71 qualified for inclusion in the study [70% with CD; 27% with concomitant immunomodulators]. At the time of drug concentration measurement [median 13.5 months after switch], 55 [77%] patients had sustained clinical remission; n = 44 [62%] composite clinical and biomarker remission; n = 40 [56%] biochemical remission; and n = 31 [43%] deep remission. The mean SC-IFX concentrations were significantly higher in patients with sustained clinical remission [p = 0.014]; composite clinical and biomarker remission [p = 0.003]; biochemical remission [p < 0.001]; and deep remission [p < 0.001] compared to patients without having these outcomes. In multivariate analysis, SC-IFX concentration was the only factor independently associated with sustained clinical remission (odds ratio [OR]: 4.7, 95% confidence interval [CI]: 3.1-12.2, p = 0.005); clinical and biomarker remission [OR: 9.21, 95% CI: 6.09-18.7, p = 0.006]; biochemical remission [OR: 37, 95% CI: 14-39.3, p < 0.001]; and deep remission [OR: 29, 95% CI: 15.7-37.4, p < 0.001]. The optimal SC-IFX concentration cut-off associated with deep remission based on ROC analysis was 20 µg/mL [sensitivity: 0.91, specificity: 0.80, accuracy: 0.85]. Combination with an immunomodulator failed to improve SC-IFX pharmacokinetics.

Conclusion: Higher SC-IFX concentrations are associated with higher rates of favourable therapeutic outcomes in IBD patients. Serum SC-IFX concentrations >20 µg/mL were significantly associated with deep remission.