PDF: ProDERM
(2022)Objective
To evaluate the efficacy and safety of intravenous immune globulin (IVIG) compared with placebo in adults with active dermatomyositis
Study Summary
• At least moderate improvement (TIS ≥40): 68% vs 33% with IVIG vs placebo
• Major improvement (TIS ≥60): 47% vs 15%
• CDASI improved significantly with IVIG
• CK levels did not differ meaningfully between groups
• 282 treatment-related AEs in IVIG group over 40 weeks; headache (42%), pyrexia (19%), nausea (16%)
• 6 thromboembolic events among IVIG-related serious AEs
• First phase 3 RCT leading to FDA approval of IVIG for dermatomyositis
Intervention
IVIG (Octagam 10%) 2.0 g/kg IV every 4 weeks for 16 weeks (4 infusion cycles) vs placebo IV every 4 weeks; open-label extension with IVIG from weeks 16–40
Inclusion Criteria
• Age 18–80 years
• Definite or probable active dermatomyositis (Bohan and Peter criteria)
• MMT-8 <142 with ≥2 abnormal core measures
• Muscle-enzyme level >1.5× upper limit of normal
• Inadequate response to prior glucocorticoid/immunosuppressive therapy, or currently on stable regimen
• Maximum prednisone 20 mg/day and up to 2 immunosuppressants permitted
• No biologic agents, cyclophosphamide, or IVIG
• No history of thromboembolic events excluded
Study Design
Arms: Array
Patients per Arm: IVIG: 47; Placebo: 48
Outcome
• At least moderate improvement (TIS ≥40): 68% vs 33%
• Major improvement (TIS ≥60): 47% vs 15%
• CDASI total activity change: significant improvement with IVIG
• CK change: no significant difference
• Quality of life (SF-36): improved with IVIG at week 16
• Serious AEs: 9 IVIG-related (including 6 thromboembolic events)
• Headache 42%, pyrexia 19%, nausea 16% in IVIG group
Bottom Line
IVIG produced significantly higher response rates than placebo in adults with active dermatomyositis: 79% vs 44% achieved at least minimal improvement (TIS ≥20) at 16 weeks (difference 35 pp; P<0.001). Moderate and major improvement rates were also significantly higher with IVIG. This was the first phase 3 RCT of IVIG in dermatomyositis and led to FDA approval of Octagam 10% for this indication. The main safety concern was thromboembolic events (6 cases).
Major Points
- ProDERM was a prospective, phase 3, double-blind, parallel-group, randomized, placebo-controlled trial of 95 adults with active dermatomyositis at 36 European and North American centers, from February 2017 to November 2019.
- Patients had definite or probable dermatomyositis (Bohan and Peter criteria), active disease with muscle weakness (MMT-8 <142 with ≥2 abnormal core measures), and were permitted background glucocorticoids (≤20 mg prednisone/day) and up to 2 immunosuppressants.
- The primary endpoint, TIS (Total Improvement Score) ≥20 at week 16, was achieved by 79% (37/47) in the IVIG group vs 44% (21/48) in placebo (difference 35 pp; 95% CI 17–53; P<0.001).
- Secondary endpoints consistently favored IVIG: moderate improvement (TIS ≥40) 68% vs 33%, major improvement (TIS ≥60) 47% vs 15%, and significant CDASI (skin disease) improvement.
- CK levels did not differ meaningfully between groups, suggesting IVIG's benefit in dermatomyositis is more related to immunomodulation affecting muscle inflammation and skin disease than CK normalization.
- Over 40 weeks, 282 treatment-related AEs occurred in the IVIG group. Most common: headache (42%), pyrexia (19%), nausea (16%).
- Six thromboembolic events occurred among 9 serious IVIG-related AEs, highlighting the known prothrombotic risk of high-dose IVIG and the importance of patient screening and monitoring.
- This was the pivotal trial for FDA approval of IVIG (Octagam 10%) for dermatomyositis in July 2021, providing the first Level 1 evidence for a therapy that had been used off-label for decades.
Study Design
- Study Type
- Prospective, phase 3, double-blind, parallel-group, randomized, placebo-controlled trial; 1:1 randomization; 16-week randomized phase + 24-week open-label extension; stratified by PhGA disease-activity score
- Randomization
- Yes
- Blinding
- Double-blind
- Sample Size
- 95
Primary Outcome
Definition: TIS ≥20 (at least minimal improvement) at week 16: 79% (37/47) vs 44% (21/48); difference 35 pp (95% CI 17–53); P<0.001
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| - (17-53) | P<0.001 |
Citation
N Engl J Med 2022;387:1264-78