Future of IIM TreatmentPreview
Open in TheBrain

Tofa/Bari/upada/ruxoli

JAK inhibition has emerged as one of the most biologically “on-target” strategies in dermatomyositis (DM) and selected IIM subsets because the type I/II interferon–chemokine axis signals through JAK-STAT and is frequently dominant in DM (and in anti-MDA5–associated disease). The evidence base has moved from case reports/series to prospective pilot trials, and—critically—now includes a positive 52-week randomized, placebo-controlled registrational trial for a TYK2/JAK1 inhibitor, marking a turning point for targeted oral therapy in DM. The tradeoff is that JAK inhibitors carry class safety liabilities (serious infections and other boxed-warning risks) that must be weighed carefully in IIM patients already exposed to steroids and multi-agent immunosuppression. [7–9]

Tofacitinib (pan-JAK) has the clearest prospective “preliminary trial” dataset in DM from the Johns Hopkins STIR open-label proof-of-concept study (12 weeks). Ten adults with active, treatment-refractory DM received tofacitinib 11 mg XR daily after washout of steroid-sparing agents; all 10 met the IMACS definition of improvement at week 12, with 5/10 (50%) achieving “moderate” *improvement and the remainder “minimal” improvement by ACR/EULAR Total Improvement Score (TIS). Skin activity improved substantially (mean CDASI activity 28 → 9.5, p=0.0005), and IFN-linked chemokines (CXCL9/10) fell in parallel*—supporting a mechanistic “IFN-signature down” signal consistent with clinical response. [1]

Baricitinib (JAK1/2) has been studied most intensively in the highest-mortality IIM phenotype: anti-MDA5 DM-associated ILD. A large retrospective cohort (n=119; 39 baricitinib-treated) reported clinical *improvement in 31/39 (79.5%), *radiographic improvement (median HRCT score 115 → 97.5), and physiologic gains (FVC 76.44% → 90.73%, all statistically significant), with marked decreases in ferritin and LDH and substantial steroid tapering (median prednisone 40 mg/day → 10 mg/day). In this cohort, 6-month survival was higher in the baricitinib group (87.2% vs 70%, p=0.047), suggesting potential benefit when added to (or integrated with) intensive background regimens—though the nonrandomized design leaves residual confounding a major limitation. [2] Smaller series and literature syntheses also support baricitinib as an option in anti-MDA5 DM-ILD when risk is high and response to standard combinations is inadequate. [3]

Brepocitinib (TYK2/JAK1 inhibitor) in VALOR, a randomized, double-blind, placebo-controlled 52-week phase 3 *trial enrolling 241 DM patients globally. Reported topline results show brepocitinib 30 mg achieved a week-52 mean *TIS 46.5 vs 31.2 *with placebo (p=0.0006), with statistically significant separation as early as week 4; key *secondary outcomes (including CDASI, MMT-8, HAQ-DI) also favored active therapy, and the regimen demonstrated meaningful steroid-sparing (among those on baseline steroids,* 62% reached ≤2.5 mg/day and 42% discontinued steroids by week 52, vs 34% and 23% with placebo*).

Response depth was notable:* >2/3 achieved at least moderate response (TIS≥40) and ~1/2 achieved major response (TIS≥60);* among moderate-to-severe skin disease entrants, 44% reached cutaneous clinical remission vs 21% with placebo. [4,5]

Here’s the most specific publicly recoverable description of permitted background immunosuppression + stability rules for VALOR (brepocitinib in adult DM). (The full protocol PDF is not publicly posted in a way that the registry pages expose all operational details line-by-line; what follows is what is explicitly stated in public records/summaries.)

Permitted background immunosuppressants (concomitant therapy)

Non-steroid immunosuppressants explicitly permitted as concomitant background therapy included:

IVIG was also allowed as background therapy.

In addition, the public eligibility text indicates subjects could have prior or current therapy with:

Dose stability rules (how long doses had to be stable before randomization)

Public summaries specify the following stability requirements:

What I cannot state with confidence from public sources

Upadacitinib (selective JAK1) and ruxolitinib (JAK1/2; systemic or topical) currently sit in the “early evidence” tier for IIM: primarily case series and disease-focused cohorts suggesting cutaneous benefit in refractory DM. A 10-patient case series reported improvement in refractory inflammatory myositis—especially cutaneous manifestations—supporting further controlled evaluation. [6] Topical ruxolitinib is now being studied formally for refractory DM skin disease (clinical trial registered), reflecting a strategy to capture cutaneous efficacy while potentially limiting systemic toxicity. [10] Across the class, the boxed-warning framework (serious infections; malignancy; MACE; thrombosis and related risks) is relevant to IIM trials and real-world use, particularly in patients with ILD, high steroid exposure, older age, or cardiovascular risk. [7–9]

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References (linked)

1.Paik JJ, et al. Study of Tofacitinib in Refractory Dermatomyositis (STIR): an open-label pilot study of 10 patients. Arthritis Rheumatol. 2021. https://pmc.ncbi.nlm.nih.gov/articles/PMC8084900/

2.Zhu S, et al. Baricitinib could improve the prognosis of anti-MDA5 antibody–positive dermatomyositis associated ILD (retrospective cohort). Arthritis Res Ther. 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12619472/

3.Harada H, et al. Baricitinib for anti-MDA5 DM-ILD: case series and literature review on JAK inhibitors. Rheumatol Int. 2024. https://link.springer.com/article/10.1007/s00296-024-05551-2

4.VALOR Phase 3 topline report (brepocitinib in dermatomyositis): week-52 TIS and key secondary endpoints. Drug Development & Delivery. Sept 17, 2025. 

5.The Myositis Association. New hope for myositis (summarizes VALOR design/enrollment and context). Dec 11, 2025. 

6.Beckett M, et al. Upadacitinib therapy in refractory inflammatory myositis: case series of 10 patients. RMD Open (BMJ). 2024. https://pubmed.ncbi.nlm.nih.gov/38242552/

7.FDA label. XELJANZ / XELJANZ XR (tofacitinib): boxed warning and safety. (most recent label PDF in FDA database). https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/203214s038%2C208246s025%2C213082s010lbl.pdf 

8.FDA label. OLUMIANT (baricitinib): boxed warning and safety. https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/207924s006lbl.pdf 

9.FDA label. RINVOQ (upadacitinib): boxed warning and safety. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/211675s015lbl.pdf 

10.ClinicalTrials.gov. Topical ruxolitinib cream for refractory cutaneous dermatomyositis (trial registration). https://clinicaltrials.gov/study/NCT06857240 

Oral Janus kinase (JAK) inhibitors have emerged as a leading targeted option for refractory idiopathic inflammatory myopathies—particularly dermatomyositis (DM)—by interrupting JAK-mediated cytokine signaling that converges on the type I interferon axis (and other pathways relevant to DM inflammation).(1,2) The current clinical evidence base is still dominated by small open-label studies and observational series, but signals are consistent for cutaneous benefit and variable for muscle outcomes.(1,2)

In a 2024 single-arm meta-analysis of 7 publications (n=91 DM/PM), JAK inhibitors were associated with a mean CDASI reduction of 17.67 points (95% CI −20.94 to −14.41), while muscle strength change by MMT was more modest and imprecise (+10.31, 95% CI −2.83 to 23.46); subgroup analyses suggested larger mean CDASI improvements with ruxolitinib (−20.00) and tofacitinib (−18.29) than baricitinib (−11.2).(1)

Prospective pilot data align with this skin-predominant effect: in the 12-week open-label STIR study (n=10 refractory DM), all 10 met IMACS improvement at week 12 and CDASI activity improved from 28±15.4 to 9.5±8.5 (p=0.0005), alongside biomarker evidence of reduced interferon signaling.(2)

Clinically, JAK inhibitors have also been deployed in difficult phenotypes such as anti-MDA5 DM with rapidly progressive ILD, where tofacitinib has been reported as salvage/adjunct therapy in severe disease, supporting the concept of interferon-driven lung inflammation as a targetable pathway.(3,4)

Safety in myositis should be framed through both class risks and observed events in these small datasets; for example, the 2024 meta-analysis noted orolabial HSV (n=1) and thromboembolism (n=2) among included reports, reinforcing the need for careful infection and thrombosis risk assessment when using this class off-label in IIM.(1)

References (numbered as cited; links)

  1. Ma C, Liu M, Cheng Y, et al. Therapeutic efficacy and safety of JAK inhibitors in treating polymyositis/dermatomyositis: a single-arm systemic meta-analysis. Front Immunol. 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC10991784/
  2. Paik JJ, Casciola-Rosen L, Shin JY, et al. Study of tofacitinib in refractory dermatomyositis (STIR): an open-label pilot study of 10 patients. Arthritis Rheumatol. 2021. https://pmc.ncbi.nlm.nih.gov/articles/PMC8084900/ https://doi.org/10.1002/art.41602
  3. Chen Z, Wang X, Ye S. Tofacitinib in amyopathic dermatomyositis–associated interstitial lung disease. N Engl J Med. 2019. https://www.nejm.org/doi/full/10.1056/NEJMc1900045
  4. Wallwork RS, Kim J, et al. Current evidence for Janus kinase inhibitors in adult and juvenile dermatomyositis and key comparisons. 2024 (review). https://pmc.ncbi.nlm.nih.gov/articles/PMC12185052/