Korean neurodegenerative disease-focused Aribio Co. Ltd. gained the U.K.’s regulatory clearance to start the phase III Polaris-AD trial on AR-1001 (mirodenafil), an investigative therapy for early Alzheimer’s disease (AD). The U.K.’s Medicines and Healthcare products Regulatory Agency gave notice of acceptance to Seoul, South Korea- and San Diego-based Aribio for the clinical study on Feb. 21 after “confirming a favorable ethical opinion,” Aribio said. AR-1001 is an oral phosphodiesterase-5 inhibitor under development to treat early AD.