Judging by the odds from the bookmakers, it will be an approximately equal match with a slight advantage for Arsenal:
2,19 - 3,60 - 3,30
but in my opinion Arsenal is now on the rise and is more likely to win (accordingly, a bet on it is profitable). A safer bet is BTTS with odds of 1.67, both teams are good in attack, so BTTS looks adequate too.
Arsenal are of course much better now than they were at the beginning of the season, and are a better team than West Ham. But West Ham is also playing very well.