Firstly, you need to check the lease contract to ascertain what break clauses, if any, you might have. For example, you may have the right to back out of the lease after a certain amount of time with enough notice, assign the lease to another business to take on the tenancy, or sublet the premises.
If these options are not applicable, you could try to negotiate a lease termination with the landlord but they are not obligated to negotiate if you are under contract. If the landlord did agree to an early termination, it’s likely they would do so on the basis that you pay a compensation fee.
If you sublet the premises, you continue to be the tenant under the original lease, and your existing responsibilities continue to be the same. In turn, your subtenant has a sublease requiring them to pay you rent, look after the premises and so on.
If you assign the lease, the new tenant takes over the tenancy responsibilities. But you may continue to be liable if the new tenant fails to pay the rent.