Compare by CDASI

You likely mean CDASI (Cutaneous Dermatomyositis Disease Area and Severity Index; most trials report CDASI-A = activity). Below are interventional dermatomyositis studies that reported CDASI as an efficacy outcome, grouped by evidence strength, with the CDASI results you can actually compare (timepoint + effect size). Because baseline severity, background therapy, and follow-up length differ, cross-trial ranking should rely most on placebo-adjusted differences in randomized trials.

Randomized, placebo-controlled evidence (best for comparison)

Dazukibart

(type I interferon pathway biologic; phase 2 RCT, skin-predominant DM)

Endpoint/timepoint: CDASI-A change at Week 12
Result: Mean CDASI-A change –19.2 for 600 mg (placebo-adjusted difference –16.3, p<0.0001); 150 mg –16.6 (placebo-adjusted difference –13.7, p<0.0001).
Interpretation: Among RCTs reporting CDASI, this is the largest placebo-adjusted CDASI-A improvement at a short (12-week)

IVIG (Octagam 10%)

— ProDERM post-hoc skin analysis (phase 3 RCT data)

Endpoint/timepoint: CDASI-A change at Week 16 (double-blind) and Week 40 (later assessment reported in the post-hoc analysis)
Result: Baseline CDASI-A ~27–28; at Week 16 CDASI-A change –10.0 (IVIG) vs –2.5 (placebo) (difference –7.5, p=0.002); at Week 40 change –10.1 vs –2.1 (difference –8.1, p=0.001).
Interpretation: Demonstrates moderate-to-large skin benefit on CDASI-A in a controlled dataset, with a placebo arm for context.

Brepocitinib (TYK2/JAK1 inhibitor)

— VALOR (phase 3 RCT; company-reported topline + deck)

Endpoint/timepoint: CDASI-A change at Week 52
Result (30 mg vs placebo): CDASI-A change from baseline –11.7 vs –7.0 (p=0.0006).
- In those with moderate–severe baseline skin disease (CDASI-A >14): mean percent CDASI-A reduction 63% vs 37%, and cutaneous clinical remission (CDASI-A ≤5) 44% vs 21%.
- Topline release also states CDASI separation as early as week 4 and significant skin benefit among key secondary endpoints (without full peer-reviewed dataset in that release).
Interpretation: Statistically significant CDASI benefit over 52 weeks; effect size appears smaller than dazukibart’s 12-week placebo-adjusted CDASI-A delta, but over a much longer trial with steroid-taper context.

Lenabasum

(CB2 agonist) — phase 2 RCT

positive signal

, phase 3

negative

Phase 2 RCT (signal): CDASI activity improvement favored lenabasum; least-squares mean difference about –6.5 vs placebo at the reported timepoint (p≈0.045).
Phase 3 (DETERMINE; overall negative): Reported no significant difference vs placebo in primary/major outcomes; CDASI did not emerge as clearly positive in topline communications.
Interpretation: Early CDASI signal did not translate into convincing phase 3 efficacy.

Open-label / observational evidence (useful, but not placebo-comparable)

Tofacitinib (JAK inhibitor)

— STIR open-label study

Endpoint/timepoint: CDASI at Week 12
Result: Mean CDASI fell from 28.0 ± 15.4 to 9.5 ± 8.5; mean change –18.5 (p=0.0005).
Interpretation: Large within-group CDASI improvement, but no placebo; magnitude is similar to dazukibart’s absolute change, but not directly comparable without a control arm.

Apremilast (PDE4 inhibitor)

—* phase 2a open-label*

Endpoint/timepoint: CDASI at ~3 months
Result: Mean CDASI decreased by 12.9 points at 3 months; most participants met the study’s predefined clinical response.
Interpretation: Suggests cutaneous benefit; uncertainty remains due to small size and open-label design.

Repository corticotropin injection (RCI)

— prospective open-label pilot

Endpoint/timepoint: CDASI-A at Week 24
Result: Median CDASI-A decreased from 16.0 (IQR 9.0–21.0) to 6.0 (IQR 5.0–7.0) (p=0.02).
Interpretation: Signal for skin improvement, but small, uncontrolled, and susceptible to regression-to-mean/background-therapy effects.

Anifrolumab (IFNAR1 blocker)

—* observational cohorts/series*

Largest open-access cohort (n=30, retrospective): CDASI-A improved quickly by Month 1, median 23 → 6 **(P<0.001).
Small prospective/series signal (n=4): Mean CDASI-A 27 → 8.75 with treatment.
Interpretation: Consistent “real-world” CDASI improvements, but not randomized (and mixed systemic involvement).

Practical “how to compare” the CDASI signals across therapies

If you want the cleanest CDASI comparison, prioritize placebo-adjusted CDASI-A changes: dazukibart (largest short-term delta) , IVIG (moderate delta in RCT dataset) , and brepocitinib (statistically significant delta at 52 weeks) .
Open-label JAK inhibitor studies (e.g., tofacitinib) show large CDASI drops, but without a control arm you should treat them as hypothesis-strengthening rather than definitive comparative efficacy.
Lenabasum is the cautionary tale: phase 2 CDASI signal did not hold in phase 3.

DM therapies with CDASI-A as a reported outcome (best available trial-level comparisons)

IVIg 2 g/kg q4w	Phase 3 RCT (ProDERM post-hoc skin analysis), N=95	Adults with active DM	Mean change from baseline at Week 16	−9.36 vs −1.16(p<0.0001)	Large, placebo-controlled skin benefitby 16 weeks; also maintained/improved through extension.
Dazukibart (anti-IFN-β)	Phase 2b RCT, N=73	Adults with moderate–severe cutaneous DM	Mean change from baseline at Week 24(CDASI-A)	−10.2 (300 mg) and −7.6(150 mg) vs −2.8 placebo	Clear placebo-controlled signal for skin activity at 24 weeks; dose–response suggested.
Lenabasum (cannabinoid receptor agonist / pro-resolving immunomodulation)	RCT, N=22	Refractory skin-predominant DM	Mean change from baseline at Day 113	−9.3 vs −3.7; between-group difference −6.5(p=0.0382)	Placebo-controlled improvement, but very small trial → effect estimate is imprecise.
Brepocitinib (TYK2/JAK1 inhibitor)	Phase 3 RCT (VALOR) – company slide deck	Adults with active DM	CDASI-A change from baseline at Week 52	−11.7 vs −7.0(p=0.0006)	Statistically significant skin improvement, but this figure is from a Priovant investor/overview deck (peer-reviewed manuscript details may refine estimates).
Tofacitinib (pan-JAK inhibitor)	Open-label pilot (STIR), N=10	Refractory DM (mostly skin-predominant)	Mean CDASI activity score baseline → Week 12	28 ±15.4 → 9.5 ±8.5(p=0.0005)	Big within-patient drop, but no control group; population enriched for skin-predominant disease.
Apremilast (PDE-4 inhibitor)	Open-label, single-arm, N=8	Recalcitrant cutaneous DM (add-on therapy)	Mean CDASI change at 3 months	Mean decrease −12.9 (SD 6.3) (P<.001)	Promising signal, but single-arm and small; good for hypothesis-generation.
Repository corticotropin injection (RCI/ACTH gel)	Prospective open-label, N=10	Refractory cutaneous DM	Median CDASI-A baseline → 6 months	19 → 10	Moderate improvement reported; open-label design limits inference.

How to interpret this clinically (skin efficacy, based on CDASI-A)

Best placebo-controlled skin evidence (published):
IVIg shows a large Week-16 separation vs placebo (about an 8-point difference in mean change), in a large RCT dataset.
Dazukibart also demonstrates a meaningful placebo-controlled signal at Week 24 with a clear placebo gap.
Lenabasum shows a statistically significant difference, but the trial is tiny, so confidence intervals would be wide even if p<0.05. Strong skin signals but caveated by design/publication status:
Brepocitinib reports statistically significant CDASI-A change at Week 52 vs placebo, but the cited numbers here are from a company overview deck (not yet a peer-reviewed primary paper in the cited source).
Tofacitinib and apremilast show large within-patient CDASI improvements, but they are single-arm studies—useful for signal, not definitive comparative efficacy.
Bottom line: if your question is “which therapies have the most credible CDASI-based evidence for improving DM skin activity,” then published, placebo-controlled data currently look strongest for IVIg and dazukibart, with lenabasum supportive but underpowered; brepocitinib looks compelling on CDASI-A in available phase-3 summary data but should be weighed against full publication details.

References (trial sources used above)

ProDERM post-hoc skin analysis (IVIg vs placebo; CDASI-A at Week 16).
Dazukibart phase 2b randomized trial (CDASI-A change at Week 24).
Lenabasum randomized trial in DM (CDASI activity change; LS mean difference reported).
VALOR phase 3 overview deck (brepocitinib; CDASI-A change at Week 52).
STIR open-label trial (tofacitinib; CDASI baseline → Week 12).
Apremilast nonrandomized controlled trial (add-on; mean CDASI decrease at 3 months).
RCI open-label trial (median CDASI-A baseline → 6 months).