Required to stop poverty, no end to sick state's failing (12)
I believe the answer is:
necessitated
'required' is the definition.
('necessitate' can be a synonym of 'require')
'to stop poverty no end to sick state's failing' is the subsidiary indication.
'to stop' is an insertion indicator (to stop can mean to block a gap).
'poverty' becomes 'need' (need is a kind of poverty).
'no end to' means to remove the last letter.
'failing' indicates an anagram.
'sick' with its last letter removed is 'sic'.
'sic'+'state'='sicstate'
'sicstate' with letters rearranged gives 'cessitat'.
'need' enclosing 'cessitat' is 'necessitated'.
(Another definition for necessitated that I've seen is " Called for".)