Switching from one infliximab biosimilar (CT‐P13) to another infliximab biosimilar (SB2) in patients with chronic plaque psoriasis

Funding sources: none. Conflicts of interest: The authors declare they have no conflicts of interest. Dear Editor, CT‐P13 and SB2 are two distinct biosimilars of the reference originator anti‐tumour necrosis factor (TNF)‐α monoclonal antibody infliximab.1,2 Real‐life evidence has shown that the switch from infliximab originator to CT‐P13 did not impair overall clinical efficacy and safety in patients with Crohn disease, ulcerative colitis, spondyloarthritis, rheumatoid arthritis, psoriatic arthritis and chronic plaque psoriasis.3,4 However, there are no studies investigating the switch from biosimilar CT‐P13 to SB2 in any immune‐mediated disorders including chronic plaque psoriasis. The objective of this observational study was to investigate the effectiveness and safety of the switch from CT‐P13 to SB2 in patients with chronic plaque psoriasis regularly followed in the outpatient psoriasis clinic of the University Hospitals of Verona, Padua and Modena. Institutional review board approval for this study was obtained. Demographic characteristics, comorbidities, severity of psoriasis measured with the Psoriasis Area and Severity Index (PASI) and age of patients at first diagnosis of psoriasis were collected. Effectiveness was evaluated by measuring PASI changes from the time of the switch (baseline) to 2, 4 and 6 months after. All patients included in the study (n = 96) had been treated previously with the infliximab originator before the first switch to CT‐P13. The mean duration of previous treatment with the infliximab originator and CT‐P13 was 97·4 ± 36·3 and 17·6 ± 8 months, respectively, as reported in Figure 1. All patients (n = 96) were switched because of nonmedical reasons, according to the drug available in the hospital pharmacy, which periodically selects the cheaper drug available.5 Safety was assessed by reporting any adverse events occurred from baseline up to 6 months after. Ninety‐six patients (78 males and 18 females) were included, with a mean age of 54·2 ± 12·6 years and mean body mass index of 28 ± 4·7. Twenty‐five (26%) patients also had psoriatic arthritis. Arterial hypertension, dyslipidaemia and type 2 diabetes mellitus were diagnosed in 46 (48%), 47 (49%) and nine (9%) patients, respectively. The mean psoriasis duration was 24·3 ± 10·7 years. The PASI remained stable during the 6‐month period of observation. In particular, PASI at the time of the switch and after 2, 4 and 6 months was 0·9 ± 2; 0·9 ± 1·6; 1·1 ± 2·2; 0·7 ± 1·1, respectively. In terms of safety, acute infusion reactions consisting of widespread rash associated with sweating and hypotension that required immediate infusion suspension and definite treatment withdrawal were observed in three patients. Seven patients had a relapse of skin or joint symptoms after the switch, so that three patients returned back to CT‐P13 and regained clinical efficacy, three patients changed biologic therapy, and methotrexate was associated to SB2 in one case. Upper respiratory infections (n = 6) and herpes zoster infection (n = 1) were also reported.