B. Riley FBR analyst Mayank Mamtani lowered his price target to $3 from $7 on Arbutus Biopharma shares after the company discontinued its most advanced pipeline program, AB-506, after observing two cases of acute hepatitis in its recently initiated Phase Ia study in healthy volunteers. While acknowledging this "material negative," he considers the stock selloff of 73% year-to-date as overdone given the continued R&D efforts that Arbutus has in other areas, most notably for AB-729, an RNAi targeting drug that remains on track to deliver efficacy data in HBV patients in the first quarter of 2020, said Mamtani. He keeps a Buy rating on the stock.