Repository corticotropin (ACTH) intramuscular or subcutaneous injection is primarily used for treating infantile spasms (West syndrome). It has also been investigated for diagnostic testing of adrenocortical function and for treating a variety of other conditions.
ACTH injection (H.P. Acthar® Gel, Questcor, and Union City, CA) is a purified, sterile preparation of the natural form of ACTH in gelatin to provide a prolonged release after intramuscular or subcutaneous injection. ACTH works by stimulating the adrenal cortex to produce cortisol, corticosterone, and a number of other hormones.
According to the 2010 product information (product labeling), repository corticotropin injection may be used in the treatment of the following conditions (1):
- Infantile Spasms: Monotherapy for the treatment of infantile spasms in infants and children under 2 years of age.
- Multiple Sclerosis: Treatment of acute exacerbations of multiple sclerosis in adults.
- Rheumatic Disorders: Indicated as adjunctive therapy for short-term administration (to tide the patient over an acute episode or exacerbation) in: Psoriatic arthritis, Rheumatoid arthritis, including juvenile rheumatoid arthritis (selected cases may require low-dose maintenance therapy), Ankylosing spondylitis.
- Collagen Diseases: During an exacerbation or as maintenance therapy in selected cases of: systemic lupus erythematosus, systemic dermatomyositis (polymyositis).
- Dermatologic Diseases: Indicated for treatment of severe erythema multiforme, Stevens-Johnson syndrome.
- Allergic States: Serum sickness.
- Ophthalmic Diseases: Severe acute and chronic allergic and inflammatory processes involving the eye and its adnexa Such as keratitis, iritis, iridocyclitis, diffuse posterior uveitis and choroiditis; optic neuritis; chorioretinitis; anterior segment inflammation.
- Respiratory Diseases: Symptomatic sarcoidosis.
- Edematous State: To induce a diuresis or a remission of proteinuria in the nephrotic syndrome without uremia of the idiopathic type or that is due to lupus erythematosus.
Contraindications for use of this agent include scleroderma, osteoporosis, systemic fungal infections, ocular herpes simplex, recent surgery, history of or the presence of a peptic ulcer, heart failure, uncontrolled hypertension, or sensitivity to proteins of porcine origin.
Unlike previous versions, the 2010 product label does not mention the use of repository corticotropin injection for diagnostic testing of adrenocortical function.
West Syndrome/Infantile Spasms
West syndrome is a rare epileptic disorder of early infancy (90% of cases are diagnosed the first year of life) consisting of three main characteristics; infantile spasm, mental retardation, and hypsarrhythmia, a specific abnormal pattern on electroencephalogram (EEG). Often the term “infantile spasms” is used synonymously with West syndrome. Infantile spasms are characterized by an initial contraction phase followed by a more sustained tonic phase.
Other treatments for infantile spasms include:
Vigabatrin (Sabril®, Lundbeck, Inc.) oral solution is another available treatment for infantile spasms. Sabril is indicated as monotherapy for pediatric patients with infantile spasms for whom the potential benefits outweigh the potential risk of vision loss.
Cosyntropin (Cortosyn®, Amphastar), a synthetic form of ACTH, is created by isolating the first 24 amino acids from ACTH peptide. Unlike the natural form of ACTH, which is given intramuscularly or subcutaneously, Cortosyn should only be given intravenously. A depot formulation of cosyntropin (Synacthen Depot) is not approved by the U.S. Food and Drug Administration (FDA) for treating infantile spasms. However, it is available through a compassionate-use program through the specialty pharmacy Caligor Rx in New York.
In December 2008, Questcor resubmitted a supplemental new drug application (sNDA) for H.P. Acthar gel (repository corticotrophin) injection to the FDA for treating infantile spasms. Approval was granted in October 2010.