Study ID | Indication | Statistical methods for generating ECA | Outcome(s) compared with ECA | Outcome timepoint (weeks) | Evidence of treatment benefit compared with ECA* | Rationale for using an ECA |
Hueber et al, 201219 | CD | Weighting | Efficacy (CDAI response rate) | 6 | No | Small study sample size |
Hyams et al, 201220 | UC | Unadjusted | Efficacy (MCS response rate) | 8 | Yes | Unethical to use internal placebo arm |
Hodkinson et al, 201321 | RA | Unadjusted | Efficacy (DAS 28 response and remission rates) | 26 | Yes | NR |
Croft et al, 202122 | UC | Unadjusted | Efficacy (MCS remission rate) | 8, 52 | Yes | Unethical to use internal placebo arm advised by regulatory organisations; low recruitment |
Hupf et al, 2021†25 | AS | Bayesian dynamic borrowing | Efficacy (ASAS 20 response rate) | 6 | NA | ECA methodology study |
Reed et al, 2021†24 | RA | Propensity score matching | Safety (SAEs) | NR | NA | ECA methodology study |
Rudrapatna et al, 2021†26 | CD | Unadjusted | Efficacy (mean change in CDAI, steroid-free CDAI remission rate) | 12, 24 | NA | ECA methodology study |
Wang et al, 2021†27 | RA | Propensity score matching | Efficacy (ACR 20 response rate) | 12 | NA | ECA methodology study |
Magnolo et al, 202223 | PsO | Bayesian dynamic borrowing | Efficacy (PASI 75, PASI 90 & IGA 0/1 response rates) Safety (AEs) | 12 | Yes | Unethical to use internal placebo arm; advised by regulatory organisations |
Norvang et al, 2022†28 | RA | Propensity score weighting | Efficacy (DAS 28 remission rate) | 24, 52, 104 | NA | ECA methodology study |
*As defined by the included study.
†Primary study objective was to examine methodological approaches for complementing prior or concurrent RCT data with external control data.
ACR, American College of Rheumatology; AE, adverse event; AS, ankylosing spondylitis; ASAS, Assessment of SpondyloArthritis International Society; CD, Crohn’s disease; CDAI, Crohn’s Disease Activity Index; DAS, Disease Activity Score; ECA, external control arm; IGA, Investigator’s Global Assessment; MCS, Mayo Clinical Score; NA, not applicable; NR, not reported; PASI, Psoriasis Area Severity Index; PsO, psoriasis; RA, rheumatoid arthritis; SAE, serious adverse event; UC, ulcerative colitis.