FDA Approves Acthar Gel for Infantile Spasms

An injectable formulation of adrenocorticotropic hormone, used off-label since the late 1950s to treat infantile spasms, has been formally approved for this indication.

The manufacturer, Questcor Pharmaceuticals Inc., announced on Oct. 15 that the Food and Drug Administration had approved H.P. Acthar gel, the trade name for repository corticotropin injection, for treating infantile spasms (IS) in infants and children younger than 2 years. IS are a rare, severe form of epilepsy that affects about 2,000 children in the United States every year, according to the company.

Acthar gel, approved by the FDA in 1952, has been used to treat IS for more than 50 years, and is recommended by the American Academy of Neurology and the Child Neurology Society as a treatment for IS. It was previously approved for various indications, including acute multiple sclerosis exacerbations and nephrotic syndrome. Acthar gel is a purified preparation of adrenocorticotropic hormone (ACTH), obtained from the pituitary glands of pigs.

At a meeting in May, in near unanimous votes, an FDA advisory panel agreed that there was enough evidence indicating that Acthar gel was effective and safe for this indication.

Questcor, which acquired the drug in 2001, has not conducted new studies of the drug but reanalyzed data from three small, published randomized controlled studies. To evaluate efficacy, these analyses used the end points of complete cessation of spasms and resolution of hypsarrhythmia on a prolonged video EEG (overall response). In the main study, published in 1996, 13 of the 15 (87%) infants treated with Acthar gel had an overall response, compared with 4 of the 14 (29%) treated with prednisone, a significant difference.

The most common side effects of Acthar are well-recognized steroid side effects, such as irritability, a cushingoid appearance (if used long enough), infections, and hypertension, but based on more than 50 years of experience, no unexpected side effects have emerged, company officials said at the advisory panel meeting.

During the open public hearing portion of the meeting, parents of children who had been treated with Acthar gel, as well as several adults who had been successfully treated for IS as infants, testified about the beneficial effect of the treatment. (Many of those testifying had their trips paid for by the company.)

Also testifying was Dr. Mary Andriola, a pediatric neurologist at the State University of New York, Stony Brook, who testified that she has used ACTH to treat IS since she started medical school in 1963. She said that she teaches residents and fellows to use ACTH so that they know how to use it, despite difficulties in the past obtaining the drug.

The only other FDA-approved treatment for IS is vigabatrin (Sabril), approved in 2009. Prednisone is also used off-label to treat IS. Acthar gel is not approved in any other country.