A descriptive analysis of real-world treatment patterns of innovator (Remicade®) and biosimilar infliximab in an infliximab-naïve Turkish population

Patients Retransitioning from Biosimilar TNFα Inhibitor to the Corresponding Originator After Initial Transitioning to the Biosimilar: A Systematic Review

Background

Transitioning patients from an originator to a corresponding biosimilar has been extensively studied in both randomized controlled trials and observational studies. Although transitioning is considered well-tolerated, with no negative impacts on efficacy and/or safety, 2.6–25.8% of patients restart treatment with the originator (retransitioning). Retransitioning to the originator can be considered an indication of biosimilar treatment failure or dissatisfaction with biosimilar treatment. Increasing our knowledge of patients who retransition might help to reduce the number of patients retransitioning.

Objective

Our objective was to estimate the cumulative incidence of patients who retransitioned from a tumor necrosis factor (TNF)-α inhibitor biosimilar to originator and to explore potential patient, disease, and treatment and implementation strategy factors associated with retransitioning.

Method

We conducted a systematic literature search in the PubMed, EMBASE, and Cochrane Central Register of controlled trials databases until March 2021. Studies on TNFα inhibitors, biosimilar transitioning, and retransitioning were included. Transitioning was defined as switching from an originator to a biosimilar, and retransitioning was defined as switching from an originator to a biosimilar and back to the originator. Characteristics of the studies were descriptively analyzed. Studies were weighted by the number of patients transitioning, and the primary outcome was the median cumulative incidence of retransitioning. For each of the factors related to patient, disease, and treatment and implementation strategy, studies were stratified according to the categories of that factor. The weighted medians and interquartile ranges (IQRs) of the cumulative incidence of retransitioning in these studies were calculated and compared to explore whether a potential association existed between these factors and the cumulative incidence of retransitioning.

Results

Of 994 screened publications, 37 were included. The weighted median cumulative incidence of retransitioning was 7.6% (IQR 6.8–17.2). Studies that included only patients with inflammatory bowel disease (6.6 vs. 15.1–17.7% for other indications), included only patients with stable disease (7.0 vs. 13.7% for including all patients), and did not offer retransitioning at the introduction of the biosimilar (7.0 vs. 11.1% for studies that offered retransitioning) reported less retransitioning. In addition, the incidence of retransitioning was lower when extra laboratory monitoring was part of the implementation strategy (1.6 vs. 6.1%) and when gainsharing (patients’ healthcare directly benefits from financial savings from transitioning) (1.4 vs. 7.2% for studies without gainsharing) was applied.

Conclusions

In studies on transitioning patients from TNFα originator to biosimilar, 8% of patients retransitioned. Retransitioning appeared to be lower in studies that included only patients with stable disease and in studies that did not offer patients the option of retransitioning at the introduction of the biosimilar. In addition, retransitioning appeared to be lower in studies that implemented extra laboratory monitoring as part of the biosimilar implementation strategy. Clinicians should consider implementing these suggestions as they might reduce retransitioning rates and improve the introduction of biosimilars in clinical practice.

PROSPERO registration ID: CRD42021226381

Supplementary Information

The online version contains supplementary material available at 10.1007/s40259-021-00508-4.

Infliximab concentrations in two non-switching cohorts of patients with inflammatory bowel disease: originator vs. biosimilar

Biosimilars are replacing originator compounds due to their similar effectiveness, safety and pharmacokinetics. Our objective was to compare the differences in pharmacokinetics and clinical outcomes between the originator infliximab (Ifx) and the biosimilar CT-P13 in a patient cohort with inflammatory bowel disease (IBD). Our cohort study included 86 patients from a historical and a prospective cohort from the start of infliximab treatment to 22 weeks later. Serum infliximab, antidrug antibody levels and other serum biomarkers were measured at weeks 0, 2, 6, 14 and 22. Remission outcomes were evaluated at weeks 14 and 22. Drug levels were measured prospectively and analysed using MANOVA. Of the 86 patients, 44 (51%) and 42 (49%) were administered the originator and CT-P13, respectively. Originator trough levels were higher than the biosimilar trough levels (35 vs. 21, 20.1 vs. 11, 6.6 vs. 2.9 and 4.3 vs. 1.7 μg/mL at weeks 2, 6, 14 and 22, respectively). A post-hoc analysis demonstrated changes in mean serum drug levels over time (p < 0.001) and according to the drug employed (p = 0.001). At week 22, 13 (81%) patients administered the originator achieved clinical remission compared with 5 (19%) patients with the biosimilar (p = 0.02). None of the patients administered the originator withdrew from the treatment compared with 7 for the biosimilar. During the study, there were significant differences in serum infliximab levels between the originator and the CT-P13 in the patients with IBD. The clinical outcomes were influenced by the type of compound administered.