(Corrects headline and first paragraph to one study, not two studies)

Aug 27 (Reuters) - Repros Therapeutics Inc said its experimental drug to treat low testosterone was superior to a leading marketed gel and a placebo in the first of two identical studies.

Patients who were given the drug, Androxal, experienced superiority in sperm concentration compared with those who used Abbvie Inc's AndroGel, said the company. The company said the proportion of subjects responding to Androxal were greater than the proportion responding to both the approved topical gel and placebo.

The results of the second study have not yet been released.

In July, the U.S. Food and Drug Administration recommended sperm concentration and responder rates as important parameters for assessing the drug's approval.

Androxal is being developed as an oral therapy to treat men of reproductive age with low testosterone.

The company said it believes it can submit an application for FDA approval by the end of the year.

Other testosterone products in the market for the condition include Endo International Plc's Aveed, an injection and Trimel Pharmaceuticals Corp's Natesto, a nasal gel.

(Reporting by Anjali Rao Koppala in Bangalore; Editing by Lisa Shumaker)