The "New" 5-Year Ixekizumab Data Is Six Years Old

A paper posted online September 16 by the Journal of the American Academy of Dermatology carries a striking claim: ixekizumab produces an "early and maintained" treat-to-target response in psoriasis patients tracked for five years. The underlying numbers, however, are not new. They come from UNCOVER-3, a Lilly-sponsored phase 3 trial whose 12-week and 108-week results were published in the New England Journal of Medicine in 2016 and in JAAD in 2017, and whose five-year efficacy and safety data already appeared in JAAD in December 2020 under lead author Andrew Blauvelt. What's new in this Armstrong-led paper, first shown as a poster at the AAD Annual Meeting in Denver this past March, is a reframing of those same five-year numbers around "treat-to-target" thresholds rather than a fresh readout.

That reframing matters because treat-to-target is not a fixed endpoint the trial was designed to measure. It is a management framework formalized by international consensus recommendations published in 2020 and 2021, which set an absolute PASI score of 2 or lower, or a physician's global assessment of clear or almost clear, as the target, with PASI 75 as a minimum acceptable threshold. Applying that framework retrospectively to a trial that enrolled its first patients years before the consensus existed is a methodological choice, not a neutral description of what UNCOVER-3 measured.

How clinicians actually use treat-to-target in practice complicates the picture further. A 2026 Canadian survey effort, CAN TARGET PSORIASIS, found that dermatologists tend to favor a broader multi-criteria approach, such as PASI of 2 or lower combined with body surface area under 2 percent, or a mix of major and minor criteria that includes quality-of-life scores, over rigid numeric cutoffs. Measured against that real-world standard, a single-drug post-hoc analysis built around one definition of "target" tells a narrower story than the headline suggests.

The five-year figures themselves depend heavily on how missing data gets handled. Blauvelt's 2020 UNCOVER-3 analysis reported an as-observed PASI 90 rate of 90.2 percent and PASI 100 rate of 66.5 percent at week 264. Using modified non-responder imputation, which counts patients who dropped out as treatment failures rather than excluding them, those figures fall to 67.1 percent and 46.2 percent. The gap between the two methods is itself a rough marker of how many patients left the trial before the five-year mark, a detail that "sustained response" framing tends to leave out.

This is also the second time Lilly-affiliated authors have mined UNCOVER-3 for an early-responder narrative. A 2022 paper in Skin Health and Disease, using the same trial, showed that patients who reached PASI 50 by week 2 had substantially better outcomes at week 60 than slower responders. The new analysis extends that argument out to five years, adding a data point to an existing publication stream rather than introducing a standalone finding.

The timing lines up with commercial pressure on ixekizumab, marketed as Taltz. Head-to-head data from the BE RADIANT trial showed bimekizumab outperforming secukinumab on PASI 100 at week 48, and ixekizumab has not published comparably favorable head-to-head numbers against bimekizumab, risankizumab, or deucravacitinib. Samsung Bioepis is also running a phase 3 trial of its biosimilar SB35 against Taltz, with primary completion expected around 2027, as the drug approaches patent expiry. Long-term durability papers built from legacy trial data are a low-cost way to keep a drug's efficacy story current while that competitive and patent picture shifts.