Reviews/Psoriasis Psoriatic Arthritis/Ixekizumab PASI 100 response rates
Pso Il17 · PSA-IL17-02 · v2
The evidence clearly shows that ixekizumab clears the skin completely in a large share of people with moderate-to-severe plaque psoriasis, but exactly how large depends heavily on when you measure and which population you look at. At the primary 12-week timepoint the corpus figures pull in opposite directions, from about 33% in a Chinese cohort [6] to about 62% in a Latin American subgroup [8]. Longer-term measurements settle around 45-49% [2][3][4], and a real-world cohort reaches roughly 68% [7]. No paper reports the pooled 12-week complete-clearance figure for the pivotal recommended dose, which is the number the claim's 35-40% band most naturally refers to [1]. The panel therefore judged the general phenomenon well-supported but the specific 35-40% band unanchored and, if anything, on the low side of what the corpus shows.
Across multiple phase 3 trials and a real-world cohort, ixekizumab produces complete skin clearance (PASI 100) in a substantial fraction of patients. Long-term extensions report 45.1% at week 156 [2], 46.3% at year 5 [3], and 48.7% at week 52 in Japanese patients [4], while a real-world study reports 69.07% at week 52 and 68.28% at five years [7]. At the week-12 primary endpoint the values diverge sharply, from 33.0% (Q2W) in Chinese patients [6] to 62.1% (Q2W) in a Latin American subgroup [8]. The pivotal pooled trials report only that complete-clearance rates were 'substantial' without a PASI 100 number [1]. The contested point: The evidence divides on whether any single figure supports the specific 35-40% band, since the two on-timepoint week-12 reads bracket it widely (33.0% [6] versus 62.1% [8]) and durable estimates cluster above it at 45-49% [2][3][4]. The panel treated the claim as directionally correct but imprecise and probably an underestimate of mature response.
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One reviewer's only job is to attack the finding. The challenges below were weighed before the grade was set.
No corpus paper reports the specific quantity claimed: the pooled week-12 PASI 100 for the pivotal UNCOVER Q2W dose is absent, with [1] stating only 'substantial' complete clearance rather than a number.
The claim specifies no timepoint, yet PASI 100 is strongly timepoint-dependent and the corpus values scatter from 29% to 69% across week-12, week-52, 3-year and 5-year reads.
Where it remains uncertain. The week-12 primary-endpoint figures disagree, from 33.0% Q2W [6] to 62.1% Q2W [8], and no paper reports the pooled pivotal week-12 PASI 100 [1].
Aleatory
PASI 100 rates differ across regional and real-world populations, from 33.0% in Chinese patients [6] to 62.1% in a Latin American subgroup [8] and ~68% in a real-world cohort [7].
Epistemic
The pooled week-12 PASI 100 for the recommended dose is not reported; [1] states only that complete-clearance rates were 'substantial'.
The load-bearing papers from a corpus of 9, each classified by what it does to the claim. Every DOI is taken from the corpus the claim was graded on.
Pivotal trials confirm high response but report no explicit PASI 100 figure, leaving the exact claimed quantity unanchored.
“in the 2-wk group 81.8% had an sPGA score of 0 or 1 and 89.1% had a PASI 75 response; rates of complete clearance were substantial”
Panel auditInternal validity: high · scope of inference: Week-12 sPGA and PASI 75 response in moderate-to-severe plaque psoriasis across three pivotal RCTs.Key limitations: no PASI 100 rate reported · qualitative 'substantial' only · week 12 only in this excerpt
Durable 3-year PASI 100 of 45.1%, above the claimed band.
“At week 156, 80.5% of patients had achieved PASI 75, 66.0% had achieved PASI 90, and 45.1% had achieved a 100% improvement from baseline in their PASI score (PASI 100)”
Panel auditInternal validity: medium · scope of inference: 3-year maintained PASI 100 in UNCOVER-3 patients on ixekizumab.Key limitations: 3-year maintenance timepoint not week 12 · no sample size · no comparator
The abstract reports only PASI 75 (83.6%) and sPGA 0/1 (74.1%), no PASI 100 number, so it cannot be placed relative to the range.
Panel auditInternal validity: medium · scope of inference: Week-108 PASI 75 and sPGA 0/1 in UNCOVER-3 patients on recommended-dose ixekizumab.Key limitations: no PASI 100 rate reported · no sample size · week 108 timepoint
3 of 9 papers shown. The full review lists all of them, with the panel’s arbitration →
Claims are graded at each quarterly release, and re-graded between releases only when a pivotal trial lands. Every change is a new version of the claim.
The phenomenon is well-supported but the precise 35-40% band is not directly reported and is contradicted on the high side by most corpus datapoints, warranting an Uncertain tier.
Release 2026-q4 re-graded every claim from its corpus under protocol v0.19. An earlier release's grade is shown for the record; it came from an earlier protocol and is not a movement.
Assumptions that carry weight but are not themselves established.
The panel records the gap that would most move the claim, and the study that would close it.
Pooled pivotal week-12 PASI 100. The number the claim most naturally refers to is absent from the pivotal report [1], leaving the band unanchored. The panel rates this the highest-importance open gap for the claim, and names the study design that would close it: Report the pooled week-12 PASI 100 for the recommended Q2W dose from the pooled UNCOVER phase 3 dataset.
Open question: What is the pooled week-12 PASI 100 rate for the recommended Q2W dose across the pivotal trials? Why it is still open: The pivotal report gives only PASI 75 and sPGA figures and calls complete clearance 'substantial' [1].
Priors is a sceptical first reader, not peer review, and not medical advice.
Release 2026-q4 · graded 18 Sep 2026 · protocol v0.19