Positive new sign found in cure – remarkable (10)
I believe the answer is:
phenomenal
'remarkable' is the definition.
(I've seen this before)
'positive new sign found in cure' is the wordplay.
'positive' becomes 'p'.
'new' becomes 'n' (abbreviation as in New Testament NT).
'sign' becomes 'omen' (omen is a kind of sign).
'found in' is an insertion indicator.
'cure' becomes 'heal' (synonyms).
'n'+'omen'='nomen'
'nomen' put into 'heal' is 'henomenal'.
'p'+'henomenal'='PHENOMENAL'
(Other definitions for phenomenal that I've seen before include "Incredible" , "Mind-blowing" , "Unusual" , "Remarkable" , "Extraordinary - help one man (anag)" .)