No. If a generic version of a chemical molecule is not developed by anyone, even after the exclusive rights on an original medicine have expired, the original medicine would still remain the only approved version of the medicine available. Sometimes a generic version is approved and available in a certain country or countries, whilst in other countries the original medicine remains the only version on the market. Other times generic versions are not produced because it costs too much to do so. For example if the medicine is designed for limited use or it is complicated to make.