Study: Switching to Biosimilar Infliximab Does Not Affect Phosphorylation Levels

Biologic treatments, including anti—tumor necrosis factor (anti-TNF) agents, can significantly improve psoriasis, but come at a high cost. While biosimilar therapies help to control the cost of biologic treatment, differences in manufacturing of innovator biologics and biosimilars have raised concerns about the potential to impact biological activity, efficacy, and tolerability.

A new study, published in the British Journal of Dermatology, used flow cytometry to compare phosphorylation levels of intracellular epitopes in peripheral blood mononuclear cells (PBMC) from patients with psoriasis in clinical remission (n = 25) who were treated with reference infliximab versus healthy controls (n = 19), and further evaluated whether a switch from reference infliximab to biosimilar CT-P13 affected intracellular phosphorylation patterns.

The researchers, led by Anders Krough Aarebrot, measured phosphorylation in PBMC before and after TNF stimulation in cells collected at inclusion, 3 months, and 12 months. Twenty-two patients were then randomized to either continue treatment with reference infliximab or switch to CT-P13.

The researchers found that:

• Basal phosphorylation in PBMC was significantly higher in patients at inclusion compared to healthy controls, even though the patients with psoriasis had achieved clinical remission.
• Patients who switched from reference to biosimilar infliximab displayed similar basal phosphorylation to the patients who remained on reference infliximab at 3 and 12 months.
• During the study period, the phosphorylation of PBMC in patients on both infliximab treatments decreased; no correlation between trough levels or the length of treatment prior to inclusion with basal phosphorylation was observed.

The authors concluded that although there were significant differences in intracellular phosphorylation of PBMC between patients with psoriasis and healthy controls, a switch to biosimilar infliximab did not result in any significant differences, a finding that suggests that CT-P13 is noninferior to its reference.

The researchers note that this is the first study to use flow cytometry in PBMC comparing patients with psoriasis with healthy controls, or to monitor patients switching from biologics to biosimilars; they suggest that using flow cytometry might represent a promising tool to monitor disease activity and treatment efficacy in patients with psoriasis in the future.