Switching patients with IBD from infliximab to a biosimilar is safe and non‐inferior to continuing treatment with originator infliximab, Australian research shows.
The reassuring findings come from an observational study led by Dr Craig Heifer of St Vincent’s Hospital, Sydney, in which four hospitals switched 202 adults from infliximab to the biosimilar CT-P13 (Inflectra) and three hospitals maintained 141 patients on originator infliximab.
The SAME study found rates of clinical deterioration – using the Harvey–Bradshaw Index (HBI) for Crohn disease patients and the partial Mayo Score (pMS) for patients with ulcerative colitis – were similar in patients who switched and those who didn’t (8% v 7%).
Secondary outcomes including infliximab trough levels and the proportion of patients with detectable anti-infliximab antibodies were also similar in both groups of patients.
There were low rates of serious adverse events (SAE) requiring discontinuation of infliximab therapy in both patient groups (4% v 3%).
SAEs were exacerbations of pre‐existing joint pain, drug‐related anaphylaxis, de novo vasculitis, and fatal metastatic lung cancer in the switch group and acute joint pain, recurrent furunculitis, severe infection requiring hospitalisation, and acute myeloid leukaemia in the control group.
“The SAME study is one of the largest controlled observational studies to evaluate the safety and clinical effects of non‐medical switching of patients with IBD,” the investigators said.
“Our study also assures Australian health professionals and patients that switching from originator to biosimilar infliximab is safe and non‐inferior to continuing treatment with originator infliximab.”
“Moreover, given the relatively low rates of clinical disease worsening and of adverse events in people switched to CT‐P13, a marked nocebo effect, as suggested by the authors of another investigation of infliximab switching, was not apparent.”
The study, published in the MJA, also found evidence of significant cost savings with the use of biosimilars.
“On the basis of six PBS‐funded 8‐weekly infliximab infusions over 48 weeks per patient, the estimated annualised cost to the PBS for the entire study group (total of 1547 vials) in May 2017 was $5.34 million, and $2.98 million in October 2019.”
“That is, the estimated annual cost to the PBS was $2.36 million lower in October 2019 (44%), or $6837 less per patient‐year of infliximab therapy.”
“This cost saving, independent of whether originator or biosimilar infliximab or CT‐P13 is used for therapy, was the result of increased market competition following the introduction of biosimilar infliximab in Australia for the treatment of IBD.”
“It is therefore anticipated that the SAME study will reassure both health professionals and patients that biosimilar infliximab is safe, clinically effective, and economical,” they said.
The study was funded with an unrestricted grant from Pfizer.