ABVC BioPharma, Inc. announced an update on the Company's eight-week long ADHD Phase IIb clinical study taking place at the University of California San Francisco (UCSF) Medical Center and five Taiwanese medical centers. Sixty-nine subjects enrolled in the study, 50 completed the study, and 11 are currently undergoing treatment. The study entitled "A Phase IIb Study of PDC-1421 Capsule to Evaluate the Safety and Efficacy in Patients with Adult attention-Deficit/Hyperactivity Disorder" is a randomized, double-blind, placebo-controlled study involving a total of approximately 100 patients in the United States and Taiwan.

The Phase IIb clinical study continues the Phase IIa clinical study of ABV-1505. Phase IIa successfully achieved the specified primary endpoints at UCSF and was accepted by the U.S. Food & Drug Administration in October 2020.