Orphan Products Extension Now Accelerating Cures and Treatments Act of 2017 or the OPEN Act This bill amends the Federal Food, Drug, and Cosmetic Act to require the Department of Health and Human Services (HHS) to extend by six months the exclusivity period for a drug or biological product approved by the Food and Drug Administration (FDA) when the product is additionally approved to prevent, diagnose, or treat a new indication that is a rare disease or condition (also known as an orphan disease). HHS may revoke an extension if the application submitted to the FDA for the new indication contained an untrue material statement. HHS must notify the public of products that receive this extension and patents related to those products. Products may receive only one extension under this bill. Extensions under this bill are in addition to other extensions. The bill applies only to products approved after enactment of this bill for a new indication that is a rare disease or condition.