267the biosimilar (n = 70), Remicade® from Europe (n = 71) or Remicade® from the
USA (n = 70). All three formulations were essentially equivalent in terms of maxi-
mal infliximab concentration (Cmax), area under the serum concentration (AUC)
time curves, and no differences in treatment-emergent adverse events among the
211 study subjects [ 11 ].
CT-P13 in Ankylosing Spondylitis
The PLANETAS trial was a phase 1, double-blind, multicenter study of 250 anti-
TNF naïve patients with active ankylosing spondylitis (AS) randomized to
receive CT-P13 (n = 125) or Remicade® (n = 125) dosed at 5 mg/kg at weeks 0,
2, and 6 then every 8 weeks up to 30weeks [ 5 ]. The AS patient population was
deemed the immune-mediated inflammatory disorder closest in approximation
to healthy volunteers in order to study pharmacokinetics and medication-related
safety and efficacy as the goal was to identify differences primarily related to the
treatment, not due to disease state [ 12 ]. Of note, AS patients with inflammatory
or rheumatic diseases were excluded from the study presumably including coex-
isting IBD diagnoses, present in approximately 5–10% of AS patients [ 13 ].
Steady-state PK data, based on AUC and Cmax values, trough levels, and medica-
tion half-life were essentially equivalent for CT-P13 and Remicade®-treated
patients at all measured timepoint post-infusions. Clinical response rates at
weeks 14 and 30 were 63% and 71% for CT-P13 versus 65% and 72% for
Remicade®, with similar changes in baseline activity scores and quality-of-life
scores at weeks 14 and 30 [ 5 ]. In the PLANETAS study, anti-drug antibodies
(ADA) occurred in 9% and 27% of CT-P13-treated patients comparable to 11%
and 23% of Remicade®-treated patients at weeks 14 and 30, respectively, with
the presence of ADA negatively influencing the PK of both agents [ 14 ].
Treatment-emergent adverse event rates at week 30 were 65% for CT-P13 versus
64% for Remicade®, including infusion reactions [ 5 ]. Partial remission rates,
adverse events, and pharmacokinetic profiles for CT-P13 and Remicade® (AUC
and Cmax) remained equivalent at week 54 [ 14 ].
In the subsequent open-label extension study, CT-P13 patients were allowed to
either continue treatment with CT-P13 (n = 88), and Remicade®-treated patients
were switched to CT-P13 (n = 86) at week 54 and followed for an additional
48 weeks. Notable findings included similar partial remission rates at weeks 78 and
102 between CT-P13-treated patients who continued therapy (70% and 81%) and
patients who switched from Remicade® to CT-P13 at week 54 (77% and 77%).
However, treatment-emergent adverse event rates were higher for the switch group
(Remicade® to CT-P13, 71%) compared to the CT-P13 patients with continued
treatment (49%). ADA were present in 22% and 25% of continued CT-P13-treated
patients at weeks 54 and 102, respectively, compared to 26% at week 54 and 31% at
week 102 for the CT-P13-switched group [ 15 ].
15 Biosimilars in Inflammatory Bowel Disease 2017: State of the Science