A once-daily oral stimulant medication for treatment of attention-deficit/hyperactivity disorder in individuals aged 6 years or older is safe and effective after 1 year of treatment, new research shows.
Results from a phase 3, multicenter dose optimization, open-label safety study of Azstarys (KemPharm) found that most treatment-emergent adverse events (TEAEs) were mild to moderate.
“This data show that Azstarys remains safe and effective for the treatment of ADHD when given for up to a year,” lead investigator Ann Childress, MD, president of the Center for Psychiatry and Behavioral Medicine, Las Vegas, said in an interview.
The study was published online in the Journal of Child and Adolescent Psychopharmacology.
Safety at 1 year
The drug is a combination of extended-release serdexmethylphenidate (SDX), KemPharm’s prodrug of dexmethylphenidate (d-MPH), co-formulated with immediate-release d-MPH.
SDX is converted to d-MPH after it is absorbed in the gastrointestinal tract. The d-MPH is released gradually throughout the day, providing quick symptom control with the d-MPH and extended control with SDX.
As reported by this news organization, Azstarys was approved by the U.S. Food and Drug Administration in 2021 on the basis of results from a laboratory classroom phase 3 trial, which showed significant improvement in ADHD symptoms, compared with placebo.
For this study, the second phase 3 trial of Azstarys, investigators analyzed data from 282 children aged 6-12 years in the United States, including 70 who participated in an earlier 1-month efficacy trial as well.
After screening and a 3-week dose-optimization phase for new participants, patients received once-daily treatment with doses of 26.1 mg/5.2 mg, 39.2 mg/7.8 mg, or 52.3 mg/10.4 mg of SDX/d-MPH.
After 1 year of treatment, 60.1% of participants reported at least one TEAE, the majority of which were moderate. Twelve patients reported severe TEAEs. Six children (2.5%) discontinued the study due to a TEAE during the treatment phase.
Investigators also measured growth and changes in sleep with the Children’s Sleep Habits Questionnaire during the 12-month study. Sleep improved on most measures and the impact on growth was mild.
There were no life-threatening TEAEs and no deaths reported during the study.
The most common TEAEs during the treatment phase were decreased appetite, upper respiratory tract infection, nasopharyngitis, decreased weight, irritability, and increased weight.
Efficacy at 1 year
ADHD symptoms improved considerably after 1 month of treatment, with responses continuing at 1 year.
At baseline, participants’ mean ADHD Rating Scale-5 (ADHD-RS-5) score was 41.5. After 1 month of treatment, scores averaged 16.1, a decline of –25.3 (P < .001).
The mean score stabilized in the 12-15 range for the remainder of the study. After 1 year of treatment, ADHD symptoms had decreased approximately 70% from baseline.
Investigators found similar results in clinical severity. After 1 month of treatment, the average Clinical Global Impressions–Severity (CGI-S) scale score was 2.5, a decline of –2.2 (P < .0001).
CGI-S scale scores remained in the 2.2-2.4 range for the remainder of the study.
These results, combined with the results of the original classroom trial, suggest Azstarys may offer advantages over other ADHD drugs, Dr. Childress said.
“In the laboratory classroom trial, subjects taking Azstarys completed significantly more math problems than subjects taking placebo beginning at 30 minutes and up to 13 hours after dosing,” Dr. Childress said. “No other methylphenidate extended-release product currently marketed in the United States has a 13-hour duration of effect.”