Hi Mr Koh,
It depends on your lease agreement, if there is any sort of exit clause for you.
If there isn't, the Landlord has every right to object to anyone else taking over from you, especially if he is not comfortable with the new tenant's trade.
Should you need any further assistance in matters relating to property, please contact me at my mobile 9748 6305. I will be happy to assess and share with you the possibilities for you in the current market.