* Roivant executive Pavan Cheruvu named new CEO
* 'Plenty of work to be done' - Cheruvu
* Axovant shares fall 20 percent to record low (Adds quotes from incoming CEO, Roivant founder, background on David Hung; updates stock price)
Feb 12 (Reuters) - Axovant Sciences Ltd's shares sank 20 percent to an all-time low on Monday after Chief Executive David Hung resigned following 10 months at the biotech firm, during which its lead drug candidate failed two key trials.
Axovant Chief Operating Officer Marion McCourt and three directors on the company's board also stepped down.
The departures come after Axovant stopped developing its lead drug, intepirdine, following the failure of two trials testing it as a treatment for Alzheimer's disease and dementia.
Bermuda-incorporated Axovant, valued at nearly $3 billion in September, has seen its stock fall 95 percent since that time. Shares fell nearly 60 percent last year.
"There is plenty of work to be done," incoming Axovant CEO Pavan Cheruvu said on a call with analysts.
Hung will continue as a scientific adviser to Roivant Sciences, a privately held firm that owns a majority of Axovant and stakes in several other biotech firms. Hung was named to Axovant's top job in April after serving as CEO at Medivation, which was bought by Pfizer for $14 billion in 2016.
Cheruvu, who was most recently chief people officer at Roivant, said Axovant will seek to add new "high quality" assets to its drug portfolio.
According to its website, Axovant is developing a treatment for patients suffering from dementia with Lewy bodies (DLB) and Parkinson's disease dementia who are also experiencing a sleep disorder. The company is also testing a treatment for Alzheimer's disease and DLB.
Cheruvu's appointment was "by no means a conventional decision, but we do believe it is the right decision for the long run," said Roivant founder Vivek Ramaswamy, also a former CEO of Axovant.
Axovant's shares fell 19.6 percent to $1.53 on Monday morning.
(Reporting by Manas Mishra in Bengaluru; Editing by Maju Samuel and Sai Sachin Ravikumar)