Genprex Inc. said its gene therapy Oncoprex was granted a fast-track designation by the U.S. Food and Drug Administration for treating lung cancer.

Oncoprex received the tag for treating non-small cell lung cancer, or NSCLC, in combination with AstraZeneca PLC's blockbuster drug Tagrisso. NSCLC represents 84% of all lung cancers, which together form the majority of cancer deaths.

Oncoprex treats NSCLC that has mutations related to epidermal growth factor receptor — a protein associated with cell division.

Austin, Texas-based Genprex's therapy injects a tumor-suppressing gene called TUSC2 into the veins. TUSC2 fixes defects in cancer cells.

The FDA's fast-track designation accelerates drug review processes and is granted to therapies that show an improvement over existing treatments.