Shanghai Ark Biopharmaceutical (ArkBio) has announced that China’s National Medical Products Administration (NMPA) has approved the New Drug Application Serdexmethylphenidate Chloride and Dexmethylphenidate Hydrochloride Capsules (Azstarys) for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) in patients aged six years and above in China.

Azstarys is a central nervous system stimulant formulated as a once-daily capsule that combines serdexmethylphenidate (SDX), a prodrug of dexmethylphenidate, with immediate-release dexmethylphenidate (d-MPH). The fixed-ratio formulation is designed to deliver rapid symptom relief while maintaining sustained therapeutic effect throughout the day. Following ingestion, the immediate-release component provides early onset of action, while SDX is gradually converted to d-MPH in the lower gastrointestinal tract, enabling extended symptom control. 

Professor Yi Zheng of Beijing Anding Hospital, Capital Medical University, and lead principal investigator of the Phase III trial, said the approval provides clinicians with a new therapeutic tool, particularly for patients who have shown suboptimal response or tolerance to existing treatments.

The approval follows positive results from a pivotal Phase III clinical trial conducted in Chinese patients with ADHD, in which Azstarys met both primary and key secondary endpoints. The study demonstrated statistically significant and clinically meaningful improvements in core ADHD symptoms compared with placebo across all assessment time points. With limited existing therapies and historical supply constraints, the combination product offers a new option for clinicians and patients.

This new capsule is the first ADHD medication approved in China to provide both rapid onset and sustained, all-day symptom control through its dual immediate-release and prodrug-based extended-release mechanism. 

Professor Jing Liu, Director of the Child Psychiatry Center at Peking University Sixth Hospital and co–lead investigator of the trial, added that the introduction of Azstarys expands treatment choices and supports efforts to improve long-term outcomes for children with ADHD in China.

The drug was previously approved by the U.S. Food and Drug Administration in March 2021 for patients aged six and older. In China, despite, ADHD prevalence among children and adolescents is estimated at about 6.4 per cent, affecting more than 23 million individuals, the treatment options in the country remain limited, with many patients discontinuing therapy due to inadequate efficacy, side effects or dosing inconvenience.