CHICAGO – according to analysis of a real world IBD cohort presented at the annual Digestive Disease Week® (DDW).
“These findings are of major socioeconomic importance, especially in low- and middle-income countries where the access to health care may be limited,” said study author Beatriz Gros, MD, an advanced clinical fellow in gastroenterology at Western General Hospital of Edinburgh.
Dr. Beatriz Gros
While switching from originator infliximab to biosimilar infliximab is known observationally to be safe and effective, data on single and double switches are scarce, and are lacking on triple switches. Infliximab, the first monoclonal antibody biologic inhibiting anti–tumor necrosis factor was approved by the Food and Drug Administration and by the European Medicines Agency in 1998 and 1999, respectively. Economic pressures led to the development of biosimilars, with the first EMA approval in 2013 and FDA approval in 2016. Uptake in Europe has been broad and expanding following evidence that early therapy is associated with better outcomes. In the United States, a recent RAND Corporation study estimated savings to be $38.4 billion or 5.9% of projected total spending on biologics from 2021 to 2025, Dr. Gros reported.
The Edinburgh IBD unit has undertaken three switch programs starting with originator to CT-P13 in 2016, CT-P13 to SB2 in 2020, and SB2 to CT-P13 in 2021. Their prospective, observational cohort study assessing safety and efficacy after switching from SB2 to CT-P13 has, as a primary endpoint, CT-P13 persistence following the switch from SB2. Stratification of persistence according to the number of switches, effectiveness, immunogenicity, and safety were secondary outcomes.
During routine virtual biologic clinic care, researchers collected clinical disease activity scores (Harvey-Bradshaw Index; partial Mayo score), laboratory parameters (including C-reactive protein [CRP], IFX trough, and antibody levels), and fecal calprotectin on 297 IBD patients (median age, 37 years; 61.6% male). Among them, 67 had three switches, 138 had two switches, and 92 had one switch. Median disease duration was longer (11.4 years) for those with three switches than for two switches (6.3 years) or one switch (2.3 years) (P < .0001)
Infliximab persistence
Out of 297 patients, 269 (90.6%) remained on infliximab at week 24. Reasons for discontinuing treatment were immunogenicity (15/297; 5.1%), secondary loss of response (7/297, 2.4%), adverse events (3/297, 1%), patient’s choice (2/297, 0.7%), and primary nonresponse (1/297, 0.3%).
While infliximab persistence was 82.6%, 92.8% and 97% in patients with one, two and three infliximab switches, respectively (P = .003), after confounder adjustment, the number of switches was not independently associated with infliximab persistence, Dr. Gros said.
What factors actually did predict infliximab persistence? Multivariable analysis identified absence of biochemical remission (CRP > 5 mg/L [hazard ratio, 3.21; 95% confidence interval, 1.43-7.24]); a diagnosis of ulcerative colitis/ inflammatory bowel disease unclassified (HR, 2.69; 95% CI, 1.19-6.06), detectable antibodies against infliximab at switch (HR, 5.81; 95% CI, 2.27-12.84) and time on infliximab (HR, 0.77; 95% CI, 0.62-0.95) as independent predictors for infliximab persistence rather than number of infliximab switches.
Clinical (P = .77), biochemical (P = .75), and fecal biomarker (P = .63) remission rates, Dr. Gros reported, were comparable at baseline, week 12 and week 24, with baseline rates for clinical, biochemical and fecal biomarker remission at 79.4%, 85.2%, and 85.3%, respectively, and at 81%, 86.5%, and 84.4% at week 24.
“Immunogenicity has been a major concern regarding multiple switches, although both our study and previous literature demonstrated that this seemed to be not happening more often to patients who had multiple switches compared to those who had fewer or none. Our study found that, of the 14 (7.1%) patients who developed de novo antibodies, none of them underwent three switches,” she said.
Dr. Gros disclosed relationships with Pfizer, AbbVie, and Jansen.
DDW is sponsored by the American Association for the Study of Liver Diseases, the American Gastroenterological Association, the American Society for Gastrointestinal Endoscopy, and The Society for Surgery of the Alimentary Tract.