WASHINGTON – Standard infantile spasm therapies such as adrenocorticotropic hormone appear to be significantly more effective than nonstandard therapies, according to a prospective study presented at the annual meeting of the American Epilepsy Society.
If infants currently treated with nonstandard therapies switched to adrenocorticotropic hormone (ACTH), there would be an increase of “one additional responder for every four infants with infantile spasms,” according to Renee Shellhaas, MD, a pediatric neurologist at the University of Michigan, Ann Arbor.
Dr. Shellhaas and her colleagues conducted a prospective study of 352 infants recorded to have spasms in the National Infantile Spasms Consortium from 2012 to 2016 and compared successful responses with the use of ACTH and other standard therapies against those with nonstandard therapies. They defined a successful response as a patient who did not take any other medication for infantile spasms for 60 days and had no infantile spasms for 30 days after finishing 30 days of treatment. Infants were split into four treatment arms: ACTH (n = 150), vigabatrin (68), oral steroids (90), and nonstandard therapies (44). Nonstandard therapies included topiramate, levetiracetam, clobazam, zonisamide, ketogenic diet, oxcarbazepine, and phenobarbital.
The proportion of male infants across all arms was 50%-64%, with an average age of 6.2 months in the ACTH group, 5.5 months in the vigabatrin group, 6.7 months in the oral steroids group, and 5.5 months in the nonstandard group. A majority of infants across all arms had hypsarrhythmia on EEG, ranging from 57% to 84%.
Dr. Shellhaas and her colleagues sought to answer the question, “What would happen if this infant had been treated with ACTH instead of the given medication?” They controlled these comparisons for selection bias by weighting them for various factors that may have increased the odds of using the comparison treatment. They also controlled for potential medical center effects, but did not adjust for dosing regimen.
If the infants who had received nonstandard therapies had instead received ACTH, their response rate would have improved from 5% to 32%, according to this analysis (P less than .01).
In comparisons against other standard treatments, response rates would not have been significantly better if patients had instead received ACTH: 29% for vigabatrin vs. an estimated 37% for ACTH and 46% for oral steroids vs. an estimated 44% for ACTH.
If there was one thing to take away from this, it is that nonstandard therapies do not work nearly as well as ACTH or other standard treatments,” Dr. Shellhaas said. “It is crucial to treat these infants with treatments that are effective.”
Dr. Shellhaas and her associates uncovered certain clinical factors associated with treatment selections. Among infants with unknown infantile spasm etiology, 30% were given nonstandard treatment, whereas 47% received ACTH. Infants who were not already on antiepileptic drugs more often received nonstandard therapies than ACTH (45% vs. 17%).
However, ACTH was still more likely to be given over nonstandard therapies to infants who had hypsarrhythmia (84% vs. 57%) or a normal head circumference (77% vs. 57%).
Dr. Shellhaas reported no relevant financial disclosures. The Pediatric Epilepsy Research Foundation funded the study.
ezimmerman@frontlinemedcom.com
SOURCE: AES 2017 abstract 1.303