Psoriatic arthritis (PsA)
CASPAR-criteria-defined autoimmune inflammatory arthritis with peripheral synovitis, enthesitis, dactylitis, axial inflammation, and concurrent skin and nail psoriasis — where biologics-dominated standard-of-care (TNF inhibitors Tier 1, IL-17A inhibitors including bimekizumab / Bimzelx FDA September 2024, IL-23 inhibitors, JAK inhibitors with black-box warnings, apremilast, abatacept) and GRAPPA 2021 / EULAR 2023 treat-to-target guidelines drive outcomes, and the editorial honest answer for this trigger is that no peptide in the Juno library has a defensible discovery-card case.
What changes during this transition
Psoriatic arthritis is a defined clinical disease — autoimmune inflammatory arthritis diagnosed by the CASPAR criteria (inflammatory articular disease plus three points from psoriasis, dactylitis, juxta-articular new bone formation, RF negativity, and nail dystrophy), with five editorially distinct disease manifestations that all enter into management decisions. Peripheral arthritis (asymmetric oligoarticular and polyarticular subsets) drives the bulk of joint-count-based assessment; enthesitis (inflammatory enthesopathy at tendon and ligament insertions, particularly Achilles, plantar fascia, lateral epicondyle, and patellar attachments — quantified by LEI or SPARCC indices) is one of the disease's defining features and a key treat-to-target endpoint; dactylitis (sausage-digit inflammation) carries its own count; axial involvement (psoriatic spondylitis, with HLA-B27 association and MRI sacroiliac and spinal signal) routes through a partly distinct intervention sequence; skin and nail PsA (PASI for skin extent, NAPSI for nail involvement) runs alongside the joint disease and changes the biologic-selection calculus. Roughly 30% of psoriasis patients develop PsA over time, with a 7-12 year lag between skin onset and joint onset being typical. PsA is distinct from psoriasis-only (which has its own standard-of-care including ruxolitinib cream Opzelura FDA July 2022, deucravacitinib Sotyktu FDA September 2022, and the IL-17 and IL-23 biologic ladder), from rheumatoid arthritis (RF and anti-CCP positivity, symmetric polyarticular pattern, different pathogenesis through CD20 B-cells and citrullinated antigens), from ankylosing spondylitis (HLA-B27-anchored axial-predominant disease — overlap exists in axial PsA), and from reactive arthritis. Standard-of-care is biologics-dominated and well-established cross-jurisdictionally. GRAPPA (Group for Research and Assessment of Psoriasis and Psoriatic Arthritis) 2021 treat-to-target guidelines and EULAR 2023 recommendations are the cross-jurisdictional anchors that drive sequencing; ACR/NPF (American College of Rheumatology / National Psoriasis Foundation) 2018 PsA guideline is the cross-jurisdictional companion. NSAIDs cover mild peripheral disease. Conventional DMARDs (methotrexate, leflunomide, sulfasalazine) carry limited PsA-specific evidence relative to their rheumatoid arthritis evidence base but remain in the early-line conversation. TNF inhibitors (adalimumab, etanercept, infliximab, golimumab, certolizumab pegol) carry the deepest Tier 1 PsA evidence base across registered indications globally. IL-17A inhibitors reshape the moderate-to-severe conversation: secukinumab (Cosentyx, FUTURE program), ixekizumab (Taltz, SPIRIT program), and bimekizumab (Bimzelx, FDA-approved September 2024 with dual IL-17A and IL-17F blockade based on BE OPTIMAL and BE COMPLETE Phase 3). IL-23 inhibitors represent the IL-23 axis paradigm shift: guselkumab (Tremfya, DISCOVER), risankizumab (Skyrizi, KEEPsAKE), and tildrakizumab (Ilumya, with PsA indication in development). JAK inhibitors (tofacitinib, upadacitinib) carry the PsA disease label, with the ORAL Surveillance trial's black-box CV-event and malignancy warnings shaping risk-benefit. PDE4 inhibitor apremilast (Otezla, PALACE) is oral and corticosteroid-free with a modest efficacy profile and clean infection-risk profile. Abatacept (Orencia, CTLA-4-Ig T-cell costimulation blockade) has the ASTRAEA Phase 3 evidence. Deucravacitinib (Sotyktu, TYK2 inhibitor) carries FDA approval for plaque psoriasis since September 2022 with active PsA Phase 3 programs (POETYK PsA-1, POETYK PsA-2). International registrations matter editorially: Japan's PMDA, Korea's MFDS, EU's EMA, and broader Asia-Pacific health authorities have registered the major biologic classes on cross-jurisdictional timelines. Comorbidity overlay is non-optional in PsA. Cardiovascular risk is elevated relative to general population (RR ~1.4-2.0 for MACE) — lipid panel, BP, ASCVD risk calculation, and statin and antihypertensive management run alongside any peptide question. NAFLD is enriched in PsA cohorts — FIB-4 or LFTs at baseline matter, particularly for users on methotrexate or apremilast. IBD overlap (PsA and Crohn's and UC share genetic ground including IL-23R polymorphisms) is the load-bearing biologic-selection consideration: IL-17 inhibitors (secukinumab, ixekizumab, bimekizumab) carry a documented IBD-exacerbation signal, while anti-TNF (with the partial-exception of etanercept which underperforms in IBD) and IL-23 inhibitors (ustekinumab and risankizumab with separate IBD registrations) are IBD-favorable. Uveitis overlap routes biologic selection toward anti-TNF. Depression burden is elevated in PsA and is part of treat-to-target. Where Juno's library fits — narrowly and with deliberate non-elevation. No peptide in the library has a discovery-card-defensible PsA case. The five drafted substrate entries (BPC-157, TB-500, KPV, Thymosin alpha-1, Larazotide) exist for honest /ask answers when users probe specific compounds, not for browse elevation. BPC-157 is community-extrapolated from gastric mucosal and tendon-and-ligament rodent work that does not engage PsA's cytokine pathophysiology. TB-500 carries Rule 6 non-propagation from the RGN-259 corneal-surface ARISE Phase 3 program plus the fragment-vs-full-length community-vs-trial-material distinction. KPV's IBD-overlap subset is where the published anti-inflammatory signal is editorially most relevant — and even there, GRAPPA 2021 IBD-aware biologic selection (anti-TNF, ustekinumab, risankizumab) is the answer, not KPV. Thymosin alpha-1 is Rule 6 non-propagation from chronic HBV registered indication plus the immune-direction concern (Th1 enhancement is the opposite of what autoimmune-suppression PsA pathophysiology argues for). Larazotide is mechanism-misaligned with PsA's cytokine pathophysiology plus the CeDLara Phase 3 contested signal weighs against the broader 'tight-junction modulation as clinical lever' thesis even within celiac. The honest editorial frame: rheumatology coordination, the biologics-dominated standard-of-care ladder, and comorbidity-aware management drive outcomes; no peptide in the library substitutes.
Important caveat
Psoriatic arthritis is rheumatology-managed standard-of-care disease — CASPAR criteria confirmation, 66/68 joint tender and swollen joint count, enthesitis count (LEI or SPARCC), dactylitis count, axial assessment (BASDAI or ASDAS where indicated), skin and nail PsA assessment (PASI, NAPSI), CRP and ESR, HLA-B27 where axial involvement is suspected, and imaging (X-ray, MRI, ultrasound) where erosive disease or axial involvement is in question are the diagnostic workup, and the biologics-dominated standard-of-care ladder is the load-bearing therapeutic intervention sequence. No peptide substitutes for that ladder. NSAIDs cover mild peripheral disease; conventional DMARDs (methotrexate, leflunomide, sulfasalazine) carry limited PsA-specific evidence but remain in the early-line conversation; TNF inhibitors (adalimumab, etanercept, infliximab, golimumab, certolizumab pegol) are Tier 1 across GRAPPA 2021, EULAR 2023, and ACR/NPF 2018; IL-17A inhibitors include secukinumab and ixekizumab and the September 2024 FDA-approved bimekizumab (Bimzelx, dual IL-17A and IL-17F blockade via BE OPTIMAL and BE COMPLETE); IL-23 inhibitors (guselkumab via DISCOVER, risankizumab via KEEPsAKE, tildrakizumab in development) work upstream of IL-17; JAK inhibitors (tofacitinib, upadacitinib) carry black-box CV-event and malignancy warnings post-ORAL Surveillance; apremilast (Otezla) is the oral PDE4 option; abatacept (Orencia) is the T-cell costimulation blockade option; deucravacitinib (Sotyktu) is TYK2-inhibitor psoriasis-approved with active PsA Phase 3 readouts. Treat-to-target with minimal disease activity (MDA) or very low disease activity (VLDA) is the framework. International registrations across Japan (PMDA), Korea (MFDS), EU (EMA), and broader Asia-Pacific authorities cover the major biologic classes. Comorbidity screening overlay is non-optional: cardiovascular risk (elevated MACE risk — lipid panel, BP, ASCVD calculation, statin and antihypertensive management), NAFLD (enriched in PsA — FIB-4 or LFTs at baseline, particularly load-bearing on methotrexate or apremilast), IBD overlap (PsA and IBD share genetic and immunologic ground including IL-23R polymorphisms — symptom screening for Crohn's or UC affects biologic selection because IL-17 inhibitors carry an IBD-exacerbation signal that anti-TNF and IL-23 inhibitors don't share), uveitis (anti-TNF-preferred for uveitis-overlap), depression as part of treat-to-target. No Juno library peptide is surfaced as a PsA discovery card — BPC-157, TB-500, KPV, Thymosin alpha-1, and Larazotide are substrate-only with editorially deliberate non-elevation because no published human PsA trial defensibly supports any of them. Rule 6 non-propagation is editorially load-bearing on this trigger: TA-1's chronic hepatitis B registered indication (~35 jurisdictions) does NOT propagate to PsA, and the immune-direction is theoretically opposed; TB-500's RGN-259 ARISE Phase 3 corneal-surface program does NOT propagate from corneal epithelium to autoimmune arthritis; BPC-157's Sikiric Zagreb foundational corpus is gastric and tendon work and does NOT propagate to PsA's IL-17 / IL-23 / IL-12 / TNF-α cytokine-driven peripheral synovitis, enthesitis, dactylitis, and axial inflammation; KPV's UC and colitis register does NOT propagate to peripheral or axial arthritis even though the IBD-overlap subset is editorially relevant; larazotide's contested CeDLara Phase 3 in celiac does NOT propagate to PsA. Cancer-history users: any peptide layered on PsA management deserves oncology coordination, and the JAK-inhibitor malignancy warnings make the broader oncology-coordination conversation already part of standard PsA care. WADA athletes: BPC-157 (S0) is prohibited at all times; TB-500 (S2 peptide hormones and growth factors) is prohibited at all times. Pregnancy and lactation in PsA is a specialist conversation — certolizumab pegol has the best pregnancy data among biologics, methotrexate is contraindicated, apremilast and JAK inhibitors require pre-conception planning — and adding a research-stage peptide on top of those decisions is not a position the evidence base supports.
Want this list to grow? The library is editorial — if there’s a peptide you think belongs on this page with documented or mechanistically-clear evidence, send us a note with the citation and we’ll review it under the same evidence-tier discipline as every other entry.