Dermatomyositis and Polymyositis
FDA-approved treatment for dermatomyositis and polymyositis
Acthar is a highly purified preparation of ACTH, which is available as a self-administered, subcutaneous or intramuscular injection1
Acthar is indicated for use during an exacerbation or as maintenance therapy in selected cases of systemic dermatomyositis (polymyositis)1
EXPLORING ACTHAR MECHANISM OF ACTION:
EFFECTS BEYOND STEROIDOGENESIS
Acthar is reported to bind to all 5 melanocortin receptors, producing both direct and indirect effects1-16
- Acthar is believed to have direct immunomodulatory and anti-inflammatory properties
- Acthar also has indirect effects through stimulation of cortisol release
- Steroids have been demonstrated not to bind to any of the 5 known melanocortin receptors
MELANOCORTIN RECEPTORS ARE EXPRESSED ON A WIDE VARIETY OF TISSUES AND CELLS, WHICH MAY AFFECT A NUMBER OF BIOLOGIC FUNCTIONS2-16
| Potentially relevant receptor expression | Potential biologic function |
| Immune cells (macrophages, monocytes, lymphocytes, neutrophils, dendritic cells, mast cells) | Anti-inflammatory and immunomodulatory properties such as: modulation of B- and T-cell function; immune cell adhesion and trafficking; NF-κB sequestration |
| Endothelial cells | Modulation of leukocyte adhesion and emigration; NF-κB activation |
| Epithelial cells | Anti-fibrotic, anti-apoptotic |
| Skeletal muscle and muscle precursor cells | Trophic factor for skeletal muscle development |
| Adrenal cortical cells | Steroidogenesis |
While the exact mechanism of action of Acthar is unknown, further investigation is being conducted.
This information is based on nonclinical data and the relationship to clinical benefit is unknown.
Dosing and Administration
- Dosage and frequency may be individualized according to the medical condition, severity of the disease, and initial response of the patient1
- The usual dosage according to the label is 40 to 80 units given intramuscularly or subcutaneously every 24 to 72 hours1
– Based on clinical experience from a retrospective case series of 5 patients with dermatomyositis and polymyositis17 :
-
4 patients received 80 units (1 mL) 2x/week for 12 weeks and 1 patient received 80 units 1x/week for 12 weeks
Side effects
- Common adverse reactions for H.P. Acthar Gel are similar to those of corticosteroids and include fluid retention, alteration in glucose tolerance, elevation in blood pressure, behavioral and mood changes, increased appetite, and weight gain1

