Initiator of profound change in fashion earlier (7)
I believe the answer is:
preform
'fashion earlier' is the definition.
(form or fashion in advance)
'initiator of profound change' is the wordplay.
'initiator of' says to take the initial letters (the letter which initiates the word).
'change' becomes 'reform' (reform is a kind of change).
The first letter of 'profound' is 'p'.
'p'+'reform'='PREFORM'
'in' is the link.
(Other definitions for preform that I've seen before include "model early" , "Give shape to in advance" , "Shape beforehand" .)