Background: The Infliximab biosimilar CT-P13 has been used since March 2015 in Italy. We report here a prolonged follow-up of a prospective, nationwide, multicentre, observational cohort (PROSIT) evaluating the safety, and clinical/endoscopic efficacy.
Methods: A structured data base has been used to record relevant serious adverse events (SAEs), clinical efficacy (partial Mayo [PM] and Harvey-Bradshaw Index [HBI]), inflammatory markers (CRP and calprotectin [calpro]) and endoscopic findings (endoscopic Mayo [EM] and Simple Endoscopic Score for Crohn's Disease [SES-CD]).
Results: Results 680 consecutive patients (373 CD, 307 UC) have been included from academic (n=13) and non-academic (n=12) referral centers. Age at the disease onset was 30.5±13.9 years in CD and 33.7±13.3 years for UC. 400 patients were naïve to anti-TNFα (192 CD, 208 UC), 171 patients (115 CD, 56 UC) had a previous exposure to one or more biologics, whereas the remaining 109 patients (66 CD, 43 UC) were switched after a mean of 18±10 previous infusions of infliximab (range 3–72). All patients were included in the safety evaluation. A total number of over 4,000 infusions were recorded; 92 SAEs (13.5%) were reported, leading to stop biosimilar in 73 patients (10.7%). IRs were 46, leading to stop biosimilar in 38 subjects (5.6%), and were significantly more frequent in patients pre-exposed to anti-TNFα (p<0.02).
Primary failure was recorded in 55/680 patients (8.1%). The efficacy of therapy was calculated following the induction regimen or at least two infusions after switching in 601 patients with a mean follow-up of 32 weeks (range 8–83). As a whole 274 patients were in remission (45.6%), 186 were considered responders (30.9%) and 62 lost the response (10.3%). The remaining patients were failure or stopped the therapy. 377 patients (222 CD) and 150 patients (89 CD) completed the follow-up of 6 and 12 months, respectively. After 1 year of CT-P13 therapy, HBI, SES-CD, CRP, and Calpro significantly (p<0.01) dropped in CD patients (7.1±3.4 vs 3.2±2; 10.1±42 vs 3±2.6; 1.9±1.7 mg/dl vs 0.9±0.8; 565±485 mg/kg vs 126±133 respectively), compared to baseline. Similarly, in UC patients PM, EM, CRP, and Calpro (6.1±2.3 vs 1.9±1.8; 2.1±0.6 vs 1.3±0.8; 3±2 mg/dl vs 0.9±0.7; 759±516 mg/kg vs 72±65, respectively) were significantly reduced (p<0.001). A deep remission was achieved in 57% and 50% of CD and UC patients in whom all information were available, respectively.
Conclusions: This is one of the largest prospective cohort of patients with IBD treated with CT-P13. After a more prologed follow-up, no further signals of difference in safety and clinical efficacy has been observed.