UPDATE 1-Axovant Sciences CEO David Hung resigns, shares tumble

(Adds background on trial failures, details on appoinments)

Feb 12 (Reuters) - Axovant Sciences Ltd on Monday said Chief Executive Officer David Hung had resigned, nearly a year after his appointment and a month after the drug developer scrapped a key clinical program.

Chief Operating Officer Marion McCourt has also stepped down, along with three members of the company's board.

The company's shares were down 14 percent in premarket trading.

The shares have lost more than 50 percent of their value since early January after Axovant abandoned its lead experimental dementia treatment, months after the same drug failed a late-stage study for Alzheimer's.

Axovant named Pavan Cheruvu, who was part of the executive leadership team at Roivant Sciences, as its new CEO.

Roger Jeffs, who recently served as co-CEO of United Therapeutics, and George Bickerstaff, former finance chief of Novartis Pharma, have joined Axovant's board, the company said. (Reporting by Manas Mishra in Bengaluru; Editing by Maju Samuel)