Multinational Trials Find Biosimilar Equivalent to Infliximab for AS and RA

Park W, Hrycaj P. Jeka S., et al. A randomised, double-blind, multicentre, parallel-group, prospective study comparing the pharmacokinetics, safety, and efficacy of CT-P13 and innovator infliximab in patients with ankylosing spondylitis: the PLANETAS study.Ann Rheum Dis (2013) 72:1605-1612 doi:10.1136/annrheumdis-2012-203091.

Yoo DH, Hrycaj P, Miranda P et al. A randomised, double-blind, parallel-group study to demonstrate equivalence in efficacy and safety of CT-P13 compared with innovator infliximab when coadministered with methotrexate in patients with active rheumatoid arthritis: the PLANETRA study.Ann Rheum Dis (2013) 72:1613-1620 doi:10.1136/annrheumdis-2012-203090

The safety and efficacy of CT-P13, a new biosimilar to innovator infliximab (INX), are equivalent to INX in patients with rheumatoid arthritis (RA) and active ankylosing spondylitis (AS), according to a related pair of studies. .

Both INX and the biosimilar are monoclonal antibodies that bind to tumor necrosis factor-α (TNFα).

The PLANETAS trial (Programme evaLuating the Autoimmune disease iNvEstigational drug  CT-P13 in AS), assigned patients with ankylosing spondylitis in a double-blind parallel-group fashion to either 5 mg/kg of CT-P13 (n=125) or INX (n=125). Most of these patients are white men in their late 30s.

In addition to confirming the equivalence of the two drugs in terms of pharmacokinetic properties, immunogenicienty, and safety, the Phase I PLANETAS study shows similar improvement outcomes at 30 weeks, according to tje Assessment in Ankylosing Spondylitis International Working Group criteria for 20% and 40% responses (ASAS20 and ASAS40).

Among the CT-P13 patients, 70% achieved ASAS20 responses and 51.5% attained ASAS40 responses, compared with 72.4% and 47.4% of INX patients, respectively. Very similar numbers of patients noted more than one adverse event such as infusion reactions and active tuberculosis (65% for the biosimilar as against 64% for INX itself),

In the Phase 3 study called PLANETRA (named similar to PLANETAS but substituting "RA" for "AS"), 606 patients were randomised receive 3 mg/kg of either CT-P13 or INX coadministered with methotrexate (MTX) and folic acid. Again, response rates were similar: 73% of patients who completed the course of CT-P13 and 70% of those who completed the INX regimen achieved an ACR20 respons rate. Treatment-related adverse events were reported for 35% and 36% of biosimilar- and INX-treated patients, respectively.

Both multicenter studies are coordinated by researchers at the Hanyang University Hospital for Rheumatic Diseases in Seoul, Korea. The investigators note that CT-P13 is expected to cost less than INX.