Was familiar with Kafka's first novel (4)
I believe the answer is:
knew
'was familiar with' is the definition.
(I've seen this before)
'kafka's first novel' is the wordplay.
'kafka's first' becomes 'k' (1st letter of 'kafka').
'novel' becomes 'new' (novel means new or fresh).
'k'+'new'='KNEW'
(Other definitions for knew that I've seen before include "Acknowledged" , "Was conscious of" , "Distinguished" , "Had learnt; sounds like modern" , "Recognised" .)