When payers, patients, or physicians discuss biosimilars, they assume that the biosimilar works just like the reference product. They also assume that the biosimilar is administered in the same way as the originator biologic. Celltrion is actively researching a new subcutaneous infliximab. This could result in a first for the biosimilar industry.
Sponsored by Celltrion and conducted in multiple sites, the research results were announced at the annual meeting of the European Congress of Rheumatology in June. The investigators presented outcomes data on the use of a subcutaneous (SC) form of infliximab-dyyb. Currently, infliximab is only available as an intravenous (IV) infusion at the physician’s office that takes at least 2 hours. Subcutaneous infliximab was given on a biweekly basis.
The researchers studied 48 patients with rheumatoid arthritis, finding that outcomes were not clinically different through 30 weeks of follow-up. Three dosages were tested, and in this small study, no ACR20 differences were reported in any subgroup receiving infliximab infusions or SC injections.
Hypersensitivity reactions did occur in one patient each receiving the lowest dose (90 mg) SC and the middle dose (120 mg). None were seen in the group receiving the highest infliximab SC dose (180 mg). Injection site reactions occurred in two patients apiece in the 90 mg and 180 mg dose cohorts. receiving subcutaneous infliximab. The formation of antidrug antibodies was detected in nine patients receiving the standard infusion, but less than half that number in each of the subcutaneous groups.
Currently, infliximab treatment requires a lengthy office visit for each infusion (every 8 wk in the maintenance phase). It is one of the key limiting factors to its use. A self-injectable formulation should result in lower administration costs, and the potential for covering the agent through the pharmacy benefit.
A phase 1, open-label trial of subcutaneous infliximab has already been conducted by Celltrion in patients with Crohn’s disease. That trial found similar outcomes between the SC and IV formulations. Another phase 1 trial is wrapping up, this one evaluating safety and pharmacokinetics in healthy volunteers. Celltrion is also sponsoring a phase 3 trial of more than 300 patients with rheumatoid arthritis. Preliminary results will not be available until December 2018.
It is not yet clear, however, what type of data the Food and Drug Administration would require for approval of a new formulation of a biosimilar. The regulatory agency may decide to treat this as it would a new route of administration for any approved product, which would focus on pharmacokinetic and pharmacology factors. Celltrion seems to be covering all of its bases.