No inflammatory disease has seen a more systematic dismantling of its pathophysiology over the past two decades than plaque psoriasis. First we learned that TNF drove the inflammation. Then IL-17A. Then IL-17F. Then IL-23. Each target proved more proximal to the actual keratinocyte pathology, and each class of drug was measurably better than the last. The question in 2026 is no longer whether biologics work — PASI 100 (complete skin clearance) is achievable in the majority of patients on the best agents — it's which sequence of treatments is optimal, whether remission is achievable without ongoing therapy, and whether a once-daily oral pill can match what quarterly injections deliver.
This article is for informational purposes only and does not constitute medical advice. Clinical trial eligibility and availability vary. Always consult a qualified healthcare professional before making any medical decisions or considering participation in a clinical trial.
Summary
Psoriasis biologics have made PASI 90 — near-complete skin clearance — achievable in the majority of moderate-to-severe patients, a benchmark that was inconceivable in the methotrexate era. Bimekizumab (dual IL-17A/F blockade) and the IL-23p19 inhibitors risankizumab and guselkumab are now the efficacy leaders. Deucravacitinib, an oral TYK2 inhibitor with a clean safety profile and no JAK-class cardiovascular warnings, is redefining what's possible without injections. Current trials are asking the harder questions: can biologics be stopped after deep remission, which patients respond to which agents based on genotype, and whether dual cytokine blockade improves outcomes further.
ClinicalMetric Analysis
- Bimekizumab's 19% oral candidiasis rate is a predictable, mechanism-based consequence of IL-17F blockade — not a safety signal to be managed by switching drugs, but one to be managed proactively at prescription. IL-17F is a primary component of mucosal host defense specifically against Candida. Blocking it reliably increases oral Candida colonization in a subset of patients. Patients with prior recurrent oral candidiasis, partial dentures (higher baseline Candida burden), or diabetes (altered mucosal immunity) are at substantially higher risk. Proactive antifungal prophylaxis (nystatin rinse or fluconazole pulse dosing) before starting bimekizumab, rather than reactive treatment after first episode, is the appropriate prescribing approach for high-risk patients.
- Biologic treatment withdrawal trials in psoriasis are the most clinically consequential and financially impactful research the field is running — and most prescribers aren't discussing the results with patients on long-term therapy. GUIDE (guselkumab) and IMMhance (risankizumab) show 40–60% of patients maintaining deep remission (IGA 0/1) one year after treatment withdrawal when they achieved PASI 100 on therapy. A patient on $25,000/year guselkumab who has maintained PASI 100 for 2 years is a candidate for a structured withdrawal trial — either in a research setting or an individualized clinical discussion about supervised dose spacing. This conversation isn't happening at the scale that the evidence supports.
- Psoriatic arthritis affects ~30% of plaque psoriasis patients and may be progressing subclinically while skin is well-controlled — and the biologic choice in skin-dominant disease should account for joint risk. GRAPPA treat-to-target guidelines recommend systematic PsA screening at every dermatology visit, not just when joint symptoms are volunteered. IL-17A/F inhibitors (bimekizumab, secukinumab, ixekizumab) and IL-23 inhibitors with strong joint evidence (guselkumab Phase 3 DISCOVER, risankizumab KEEPsAKE) should be preferentially chosen in patients with any joint symptoms over agents with weaker musculoskeletal data. Treating skin alone while ignoring the 30% joint comorbidity risk is treating part of the disease.
Bimekizumab: Why Blocking Both IL-17A and IL-17F Matters
Secukinumab (Cosentyx) and ixekizumab (Taltz) established anti-IL-17A blockade as the gold standard for plaque psoriasis, delivering PASI 90 in 59–68% of patients at 16 weeks — a major step up from TNF inhibitors. But a biologically important observation emerged: IL-17F, the other predominant IL-17 isoform, also drives keratinocyte proliferation and neutrophil recruitment, and it's present at roughly equal concentrations to IL-17A in psoriatic plaques. Blocking only IL-17A leaves that second driver intact.
Bimekizumab (Bimzelx, UCB) was specifically designed to address this. The Phase 3 BE VIVID (NCT03370133), BE READY (NCT03410499), and BE SURE (NCT03412747) trials enrolled over 3,000 patients collectively and showed bimekizumab achieved PASI 90 in 85–91% and PASI 100 in 60–68% — dramatically outperforming secukinumab in direct comparisons within BE SURE (PASI 100: 61% vs. 49%). FDA approval came in October 2023. The main cost is oral candidiasis, which occurs in approximately 19% of patients; this reflects IL-17F's normal role in mucosal host defense and is typically mild and manageable. Current recruiting trials are evaluating bimekizumab for psoriatic arthritis (the BE OPTIMAL trial, which also showed strong joint outcomes), for patients who have failed prior IL-17A inhibitors, and for long-term durability after treatment withdrawal.
IL-23 Inhibitors: Upstream Targeting and Quarterly Dosing
IL-23p19 inhibitors work one step upstream of IL-17: they block the cytokine that drives Th17 cell differentiation into IL-17-producing cells in the first place. This upstream mechanism has a practical consequence that matters a lot to patients — because you're interrupting the instructional signal rather than mopping up the downstream product, the drugs work durably on infrequent dosing schedules.
Risankizumab (Skyrizi, AbbVie) achieved PASI 90 in 75% of patients at 16 weeks in the UltIMMa-1 (NCT02684370) and UltIMMa-2 (NCT02684357) trials, with PASI 90 maintained in 82% at week 52 — more durable than ustekinumab comparators. After the induction phase, dosing drops to every 12 weeks, meaning just four injections per year for maintenance. AbbVie has now secured approvals across psoriasis, psoriatic arthritis, Crohn's disease, and ulcerative colitis, and trials evaluating risankizumab in additional immune conditions are ongoing.
Guselkumab (Tremfya, J&J) pioneered the selective IL-23p19 class and has demonstrated exceptional durability: PASI 90 rates of 84% at week 48 in the VOYAGE 1 and VOYAGE 2 trials, with data supporting extended dosing intervals to every 16 weeks in confirmed deep responders. A dual-blockade trial combining guselkumab with secukinumab (ECLIPSE extension data) has produced near-universal PASI 90 rates in the combination arm, raising the mechanistic question of whether simultaneously blocking both IL-23 and IL-17 improves outcomes beyond what either achieves alone — though cost and the incremental benefit in already-high responders remain genuine barriers to this approach entering practice.
Deucravacitinib: The Oral Option That Actually Works
The history of oral psoriasis treatment is a history of modest efficacy. Methotrexate requires lab monitoring and carries hepatotoxicity risk. Apremilast (a PDE4 inhibitor) achieves PASI 75 in about 35–40% of patients — useful, but well below biologic benchmarks. JAK inhibitors are efficacious but carry an FDA boxed warning for cardiovascular events, VTE, and malignancy that has dampened enthusiasm. Deucravacitinib (Sotyktu, Bristol Myers Squibb) changes this calculus.
Deucravacitinib is a selective TYK2 inhibitor that works through an unusual mechanism: rather than blocking TYK2's active catalytic site (which is homologous to JAK1/2/3 and produces cross-reactivity), it binds the regulatory pseudokinase domain — a unique allosteric pocket not shared by the JAK kinases. This explains both its selectivity and its cleaner safety profile. TYK2 transmits signaling from IL-12, IL-23, and type I interferons — all psoriasis-relevant pathways — without affecting JAK1/2/3-dependent pathways involved in erythropoiesis and immune surveillance.
The POETYK PSO-1 (NCT03624127) and POETYK PSO-2 (NCT03611751) Phase 3 trials enrolled over 1,600 patients each and compared deucravacitinib to both placebo and apremilast. Results: PASI 75 in 53–58% for deucravacitinib vs. 35–40% for apremilast and 9% for placebo. The PASI 90 comparison was more striking — 28–34% vs. 10–12% for apremilast — meaning deucravacitinib approximately tripled the rate of near-complete skin clearance compared to the prior oral standard. There are no cardiovascular warnings, no mandatory lab monitoring, and no dose titration. It's once-daily oral from the first day. For patients who refuse injectable therapy or who have access barriers to infusion-based biologics, this is a genuinely meaningful advance.
BMS is currently running deucravacitinib Phase 3 trials in psoriatic arthritis (POETYK PsA, NCT04908111), systemic lupus erythematosus, and inflammatory bowel disease. If the psoriatic arthritis data holds, deucravacitinib could become the first oral agent that addresses both the skin and joint manifestations of psoriatic disease at biologic-competitive efficacy levels.
Difficult-to-Treat Locations and the New Topicals
Percent body surface area involvement is a poor proxy for quality-of-life burden in psoriasis. A patient with 4% BSA but involvement of the scalp, nails, palms, soles, and genital skin can be far more functionally impaired than someone with 15% BSA on the trunk. Clinical trials are increasingly designed to specifically evaluate these difficult-to-treat areas, and the regulatory agencies are paying attention — FDA guidance now encourages trials to include dedicated endpoints for scalp, nail, palmoplantar, and genital disease.
Tapinarof (Vtama, Dermavant) is the most mechanistically novel topical to reach patients in decades. It's an aryl hydrocarbon receptor (AhR) agonist — a transcription factor pathway that normalizes keratinocyte differentiation and suppresses inflammatory cytokine production, including IL-17 and IL-22, through a mechanism entirely different from corticosteroids or calcineurin inhibitors. FDA approved in May 2022 for plaque psoriasis in adults. Phase 3 trials showed PASI 75 in approximately 36% at week 12 with once-daily application, with a meaningful proportion achieving clear or almost clear skin. The drug is approved for use on any body surface including sensitive areas where steroids are problematic.
Roflumilast cream (Zoryve, Arcutis) is a topical PDE4 inhibitor approved in 2022 for body plaque psoriasis and in 2023 for scalp psoriasis in a foam formulation. Phase 3 data showed 28–42% of patients achieving Investigator Global Assessment 0/1 (clear or almost clear) at week 8 — competitive with mid-potency topical steroids without the atrophic side effects, making it viable for long-term use on face, skin folds, and genital skin. Trials of higher-concentration roflumilast foam for intertriginous and genital psoriasis are ongoing, addressing exactly the areas where patients have historically had the fewest safe long-term options.
Key Takeaways
- Bimekizumab (dual IL-17A/F blockade) achieves PASI 100 in 60–68% of patients — complete skin clearance in the majority — based on BE VIVID/BE READY/BE SURE Phase 3 data.
- IL-23p19 inhibitors (risankizumab, guselkumab) deliver durable PASI 90 on quarterly dosing — four injections per year — with responses that hold through 52 weeks better than any prior biologic class.
- Deucravacitinib (POETYK PSO-1/PSO-2) outperforms apremilast with ~3x higher PASI 90 rates, no JAK-class cardiovascular warning, no lab monitoring, and once-daily oral dosing — the first oral agent that genuinely competes with biologics in a meaningful subset of patients.
- Tapinarof (AhR agonist) and roflumilast cream (PDE4 inhibitor) offer novel topical mechanisms for difficult-to-treat areas — scalp, nails, genitalia — where long-term steroid use is problematic.
- Active recruiting trials are evaluating bimekizumab and deucravacitinib for psoriatic arthritis (BE OPTIMAL, POETYK PsA), testing biologic withdrawal strategies for deep remitters, and exploring dual IL-23+IL-17 blockade for biologic-refractory disease.