Genprex Inc. announced that the FDA has granted orphan drug designation to the company's lead drug candidate, Reqorsa immunogene therapy (quaratusugene ozeplasmid, GPX-001), for the treatment of small cell lung cancer (SCLC). Reqorsa contains a plasmid that expresses the tumor suppressor gene TUSC2, the expression of which is reduced or not present in SCLC.