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.
Nina L. Kaufman, Esq. is an award-winning New York City attorney, edutainer and author. Under her Ask The Business Lawyer brand, she reaches thousands of entrepreneurs and small business owners with her legal services, professional speaking, information products, and LexAppeal weekly ezine. She also writes the Making It Legal blog.