The most common and most likely answer to this crossword clue is the 8 letter word HITHERTO
I've seen this crossword clue in Financial Times
H
I
T
H
E
R
T
O
More clues leading to the result HITHERTO
- Strike leading actor without regret ultimately, up until now
- Thro’ it, he flourished, previously
- Chart-topper having other arrangement previously
- Success with other plan so far
- Until now, hot one – hotter after erupting
- Other arrangement supporting strike so far
- 17 Success with other arrangement so far
- Success – the girl’s almost top up to now
- At one time a chart-topper with other arrangement
- Woman against supporting strike until now
Buddy explains!

The straight part
We know that "until now" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case until now = hitherto.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HITHERTO mean?
HITHERTO adverb- Up to this or that time.