Effectiveness of Infantile Spasm Treatments Compared

A total of 358 infants with IS were identified and analyzed as part of the study
A total of 358 infants with IS were identified and analyzed as part of the study

Despite their continued use, nonstandard medications are not as effective for the treatment of infantile spasms (IS) compared to standard therapy with adrenocorticotropic hormone (ACTH), according to results of a study presented at the AES Annual Meeting 2017.

The aim of the study was to compare the efficacy of ACTH to vigabatrin, oral corticosteroids, and other IS treatment options. Data from the National Infantile Spasms Consortium (NISC) database published between 2012 and 2016 was used for analysis.

Response to treatment was considered successful if the patient did not require additional IS medication for 60 days and did not experience spasms for 30 days upon completion of 30 days of treatment. Selection bias was adjusted for using propensity score methods and adjustment variables were as follows: demographics, history of epilepsy, neurologic history, and procedures such as MRI and EEG. No adjustments were made for dosing regimens. 

A total of 358 infants with IS were identified; 312 (87%) were administered standard treatment with ACTH (n=150), vigabatrin (n=71), or oral corticosteroids (n=91), and 46 (13%) were administered nonstandard therapy with topiramate (n=25), levetiracetam (n=8), clobazam (n=6), zonisamide (n=3), a ketogenic diet (n=2), oxcarbazepine (n=1), or rufinamide (n=1).

Results found that infants with an unknown epilepsy etiology, a normal MRI, an EEG displaying hypsarrhythmia, or those not already taking an AED were more likely to be administered ACTH. Additionally, it was found that if infants had received ACTH rather than treatment with nonstandard therapy, the observed response rate would have improved from 5% to an estimated response rate of 32% (95% CI: 10, 67). The authors reported, “There was not a significant estimated difference for switching from vigabatrin to ACTH (observed 29% to estimated 37% [19, 60]) nor for switching from oral steroids to ACTH (observed 46% to estimated 44% [35, 54]).”

Despite their limited efficacy, nonstandard medications are still used as initial treatment for IS in infants. “For infants currently treated with nonstandard therapy, changing treatment to ACTH would lead to one additional responder for every four infants with IS,” the authors concluded.   

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Reference

Shellhaas, R et al. Comparative effectiveness of ACTH versus other therapies for infantile spasms: Counterfactual calculations and potential effect of practice change. Presented at AES annual meeting in Washington, DC. Abstract 1.303.