You can try speaking to your landlord to see if he/she/it will let you out of the lease early. It's possible that the landlord could find another tenant quickly (at an even higher rent).

You could also see if you could find another company to take over the balance of your lease and introduce that company to the landlord. If not, though, your business is stuck (unless it files for bankruptcy protection). If you've signed a personal guaranty, the landlord could come after you personally.