Ankylosing spondylitis (AS / axSpA)
HLA-B27-associated axial spondyloarthritis — inflammatory back pain, sacroiliitis, syndesmophyte formation, eventual ankylosis. The modern axSpA umbrella covers radiographic AS (classic) and non-radiographic axSpA (nr-axSpA); peripheral SpA spectrum overlap exists. Standard-of-care is one of the most aggressive in rheumatology: continuous NSAIDs first-line, then TNF inhibitors, then IL-17A inhibitors (secukinumab, ixekizumab, bimekizumab / Bimzelx FDA-approved August 2024 for AS and nr-axSpA), then JAK inhibitors (tofacitinib FDA 2021, upadacitinib FDA 2022) with ORAL Surveillance black-box warnings. Comorbidity drives biologic selection — uveitis (anti-TNF preferred), IBD (IL-17 carries IBD-exacerbation signal), psoriasis. ACR/SAA/SPARTAN 2019 + ASAS-EULAR 2023 guidelines drive sequencing. 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
Ankylosing spondylitis sits inside the modern axial spondyloarthritis (axSpA) umbrella alongside non-radiographic axSpA (nr-axSpA), with peripheral SpA spectrum overlap. HLA-B27 carries most of the genetic risk; ASAS criteria + sacroiliac MRI drive early diagnosis. The treatment ladder is well-mapped. Continuous NSAIDs are first-line with the unique observation that continuous-dose NSAIDs may slow radiographic progression — the only DMARD-like effect any analgesic has demonstrated in this disease. TNF inhibitors (adalimumab, etanercept, infliximab, golimumab, certolizumab pegol) are second-line with monoclonals preferred over etanercept for uveitis overlap. IL-17A inhibitors are third-line: secukinumab (Cosentyx), ixekizumab (Taltz), and bimekizumab (Bimzelx, FDA-approved for AS and nr-axSpA in August 2024 with dual IL-17A and IL-17F blockade). JAK inhibitors are fourth-line: tofacitinib (FDA-approved for AS in 2021), upadacitinib (FDA-approved for AS in 2022), both carrying ORAL Surveillance black-box CV-event and malignancy warnings. Conventional DMARDs (sulfasalazine, methotrexate) only have a role in peripheral disease, not axial. Physical therapy and consistent exercise are first-line non-pharmacologic and are not optional. Comorbidity drives biologic selection in a way that matters editorially. Uveitis overlap (acute anterior uveitis is the most common extra-articular AS comorbidity, ~30% lifetime prevalence) — anti-TNF monoclonals (adalimumab, infliximab) are preferred over etanercept (which underperforms in uveitis) and over IL-17 agents. IBD overlap (~5-10% of AS patients carry clinically diagnosed IBD; subclinical ileal inflammation appears in roughly half of AS patients on ileocolonoscopy studies) — IL-17 inhibitors (secukinumab, ixekizumab, bimekizumab) carry a paradoxical IBD-exacerbation signal; anti-TNF monoclonals and IL-23 pathway agents are preferred. Psoriasis overlap is well-covered by IL-17 and IL-23 agents. The AS clinical picture: inflammatory back pain (insidious onset, improvement with exercise, worsening with rest, morning stiffness >30 minutes), sacroiliitis (the disease's defining feature, identified on sacroiliac MRI for early disease or X-ray for chronic disease), syndesmophyte formation with progression to bamboo spine in advanced cases, enthesitis (Achilles, plantar fascia, costochondral junctions), peripheral arthritis in a subset, and the extra-articular comorbidity stack (uveitis, IBD, psoriasis). Treat-to-target with BASDAI < 4 / ASDAS < 2.1 is the framework. Cardiovascular risk is elevated relative to general population; osteoporotic vertebral fracture risk is elevated due to chronic inflammation + reduced mobility, paradoxically alongside ankylotic syndesmophyte formation. Where Juno's library fits — narrowly and with deliberate non-elevation. No peptide in the library has a discovery-card-defensible AS 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. BPC-157 and TB-500 carry generic 'joint healing' framing that doesn't engage the IL-17/IL-23 axis the disease runs on. KPV gets a nod through the IBD-overlap angle but isn't a substitute for IBD-directed therapy or for IBD-aware biologic selection. Thymosin alpha-1 raises the same Th1-direction concern as in PsA. Larazotide is the most editorially interesting — the gut-joint axis in axSpA (HLA-B27 + subclinical ileal inflammation, microbiome dysbiosis signatures) is one of the better-evidenced mechanistic links in rheumatology — but the lead-indication celiac Phase 3 (CeD-LIFT / CeDLara, 2022-2023) did not meet its primary endpoint and there's no AS-specific trial. The honest editorial frame: rheumatology coordination, the biologics-dominated standard-of-care ladder, comorbidity-aware biologic selection, physical therapy and structured exercise, and treat-to-target with BASDAI and ASDAS endpoints drive outcomes.
Important caveat
AS is rheumatology-managed standard-of-care disease — HLA-B27 testing, sacroiliac MRI for early diagnosis, X-ray for chronic disease, BASDAI / ASDAS-CRP / MASES enthesitis scores, CRP / ESR, comorbidity screening (uveitis with annual ophthalmology, IBD symptom screening with fecal calprotectin where indicated, psoriasis, cardiovascular risk, osteoporosis) drive the workup. The standard-of-care ladder: continuous NSAIDs first-line (with the unique observation that continuous dosing may slow radiographic progression — the only DMARD-like effect any analgesic has demonstrated in this disease); TNF inhibitors (adalimumab, etanercept, infliximab, golimumab, certolizumab pegol) with monoclonals preferred for uveitis overlap (etanercept underperforms in uveitis); IL-17A inhibitors (secukinumab, ixekizumab, bimekizumab / Bimzelx FDA-approved August 2024 for AS and nr-axSpA with dual IL-17A and IL-17F blockade); JAK inhibitors (tofacitinib FDA 2021, upadacitinib FDA 2022) with ORAL Surveillance black-box CV-event and malignancy warnings. Conventional DMARDs (sulfasalazine, methotrexate) only have a role in peripheral disease, not axial. Physical therapy and structured exercise are first-line non-pharmacologic. ACR/SAA/SPARTAN 2019 and ASAS-EULAR 2023 guidelines drive sequencing. Treat-to-target with BASDAI < 4 / ASDAS < 2.1. Comorbidity-driven biologic selection is non-optional: uveitis overlap → anti-TNF monoclonals preferred (etanercept and IL-17 agents underperform in uveitis); IBD overlap → IL-17 inhibitors carry an IBD-exacerbation signal so anti-TNF monoclonals (with the partial exception of etanercept which underperforms in IBD) and IL-23 pathway agents are preferred; psoriasis overlap covered well by IL-17 and IL-23 agents. Cardiovascular risk elevated; osteoporotic vertebral fracture risk elevated despite syndesmophyte formation. No Juno library peptide is surfaced as an AS discovery card — BPC-157, TB-500, KPV, Thymosin alpha-1, and Larazotide are substrate-only with editorially deliberate non-elevation. Rule 6 non-propagation: BPC-157's Sikiric Croatian gastric and tendon-ligament rodent corpus does NOT propagate to HLA-B27-driven IL-17/IL-23 axis spondyloarthropathy; TB-500's RGN-259 ARISE Phase 3 corneal-surface program does NOT propagate from corneal epithelium to axial inflammation; KPV's UC / colitis register has limited propagation to AS even through the IBD-overlap subset (where IBD-aware biologic selection per ASAS-EULAR 2023 is the answer, not KPV); Thymosin alpha-1's chronic hepatitis B / C registrations across multiple non-US jurisdictions do NOT propagate to AS, and the Th1-enhancement direction is theoretically opposed to autoimmune-suppression pathophysiology; Larazotide's contested CeD-LIFT Phase 3 celiac signal does NOT propagate to AS. Red flags: new eye pain / photophobia / vision change → urgent ophthalmology (uveitis); new persistent GI symptoms (chronic diarrhea, blood in stool, weight loss) → gastroenterology referral before next biologic decision; sudden severe back pain after minor trauma in long-standing AS → imaging before assuming flare (ankylosed spine has elevated fracture risk); cauda equina symptoms → emergency. WADA athletes: BPC-157 (S0) and TB-500 (S2) prohibited at all times. Pregnancy: certolizumab pegol has the best pregnancy data among biologics; methotrexate is contraindicated; rheumatology + maternal-fetal medicine coordination required.
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.