Enthusiasm dulled for new US biosimilar Inflectra for Rheumatoid Arthritis.
Amidst the several studies demonstrating the equivalence between Celltrion’s Inflectra® and Janssen’s Remicade®, reports from a team of investigators from the US and Turkey (including Janssen researchers) at the recent American College of Rheumatology’s annual meeting may temper enthusiasm for the new biosimilar. Inflectra was launched in the US by Pfizer in late November.
These 2 retrospective studies attempted to better understand patient adherence with both the biosimilar (marketed as Remsima in Turkey) and originator product, as part of switching protocols. Patient data were examined from the Turkish National Ministry of Health database.
In the first study, 1,044 patients with rheumatoid arthritis who had not previously taken infliximab either started treatment with Remicade or Remsima (roughly 80% and 20%, respectively). Patients receiving Remicade recorded a mean 5.2 infusions and a mean dose of 4.7 vials per infusion (q8wks), compared with 3.6 doses and 5.8 vials (q9wks) for Remsima. After 6 months of treatment, 55% of those taking the originator drug discontinued treatment (partly the result of switching). Twenty-four percent of these patients switched to at least 1 other biologic (8% switched to Inflectra). For those starting Remsima treatment, discontinuation was recorded in 63%, with 31% switching to another biologic therapy (20% initially switched to Remicade).
The discontinuations may be significant, but the switching data may not be. Without understanding why a patient would switch from a biosimilar to the originator product, this may be difficult to tease out the implications. Clinically, it may not make a great deal of sense to switch from a biosimilar to the originator product (because of the similarity in the molecules and effects), whereas economically, it would make more sense to switch from Remicade to Remsima. If a patient is not responding adequately to one, the more likely protocol would be to try a different biologic or other approach.
Further real-world data are needed to understand if this truly indicates the discontinuation or switch to another therapy because of ineffectiveness, side effect, or inability to tolerate the medication.