UPDATE 1-Repros testosterone drug gets key US patent; shares up

* Says term of the patent will expire on March 19, 2023 * Shares rise as much as 19 pct

Aug 11 (Reuters) - Repros Therapeutics Inc (RPRX.O) said its lead drug candidate for treating testosterone deficiency in men received a key patent from the U.S. Patent and Trademark office, sending its shares up as much as 19 percent.

The company, which focuses on developing treatments for reproductive disorders, said the term of the U.S. patent for the drug Androxal will expire on March 19, 2023.

On Monday, Repros said the U.S. Food and Drug Administration agreed with the company's proposal to conduct two late-stage studies in order to demonstrate the benefit of Androxal in normalizing testosterone levels while preserving fertility.

The drug is being developed for the treatment of secondary hypogonadism, or a defect of the gonads that results in the underproduction of testosterone.

Shares of Woodlands, Texas-based Repros were up 15 percent at 42 cents in early-morning trade Wednesday on Nasdaq. They touched a high of 44 cents earlier in the session. (Reporting by Krishnakali Sengupta in Bangalore; Editing by Maju Samuel)