H.P. Acthar Gel (adrenocorticotropic hormone or ACTH), marketed by Mallinckrodt Pharmaceuticals, is a hormone that works by stimulating the body to produce more adrenocortical hormones. It is used to treat conditions caused by allergies, breathing issues, blood or endocrine problems, arthritis, skin or eye problems, bowel inflammation, certain cancers, and multiple sclerosis (MS).
For MS patients, Acthar Gel has been approved by the U.S. Food and Drug Administration for short-term treatment of acute relapses or flare-ups. Studies have shown that the gel is effective in speeding recovery from an MS relapse, but there is no evidence that it affects the natural progression of the disease or its outcome.
Acthar Gel is available for people with MS who do not tolerate the side effects from high doses of corticosteroids, prefer self-injection, have been treated without success with corticosteroids, or have difficulty receiving medication into their bloodstream.
For acute MS exacerbations, 80–120 units of Acthar Gel are usually injected once daily for two to three weeks, and then the dose is gradually decreased. If it is administered at home, the injection procedures must be carefully followed.
How H.P. Acthar Gel works
How Acthar Gel works is not entirely understood, but its anti-inflammatory properties is thought to help inhibit the immune system’s ability to attack myelin, the fatty substance that surrounds and insulates nerve fibers.
Acthar Gel’s active ingredient is ACTH, which is a peptide or small protein that binds to melanocortin receptors (MCR) on immune cells. This initiates a signaling cascade that leads to the inhibition of NF-ĸB, which then suppresses the reproduction of inflammatory cells.
ACTH can also bind to MCR receptors that are present on adrenal cortical cells found in the adrenal glands above the kidneys. This binding stimulates the production of the hormone cortisol. Because cortisol is a corticosteroid — which is also used to treat acute MS relapses — Acthar Gel’s benefit might partly be due to its ability to increase the production of corticosteroids.
H.P. Acthar Gel in clinical trials
Methylprednisolone and other corticosteroids are known to cause neuropsychiatric side effects, such as mood changes. A case series involved six patients with relapsing-remittent MS (RRMS) who had previously experienced detrimental mood changes with methylprednisolone treatment. All six were injected with 80 iu of Acthar Gel per day. MS symptoms improved, and the rate of neuropsychiatric side effects was low.