UPDATE 2-Repros: adverse effects of Proellex not yet resolved

* 4 patients still under close watch

* Shares fall to their four-year low (Adds details, more analyst' comments, updates share movement)

BANGALORE, July 23 (Reuters) - Repros Therapeutics Inc (RPRX.O) said it was yet to resolve the adverse effect caused by elevated levels of liver enzymes in four patients, who were treated with the company's experimental drug for uterine fibroids.

Shares of the company closed down nearly 40 percent at $2.99 Thursday on Nasdaq. They hit a four-year low of $2.94 earlier in the day.

Repros also said that all four patients were kept under close watch.

However, on July 7, the company had said all the adverse events that occurred in the first four months of the treatment, which involved nine people, were resolved without intervention upon discontinuation of the product.

"This kind of contradicts what they said on the July 7 press release," Wedbush PacGrow analyst Kimberly Lee said.

Earlier this month, Repros discontinued the use of the higher, 50 mg dosage of its lead drug, Proellex, after it found dose-dependent increase in liver enzymes -- a marker for toxicity -- in a low percentage of women. [ID:nBNG71565]

Endometriosis is a condition where tissue similar to the lining of the uterus are found elsewhere in the body and symptoms include pelvic pain, infertility and severe fatigue.

"The persistence of these elevations could be a longer-term regulatory and commercial liability," Oppenheimer and Co analyst Brian Abrahams said in a note.

"Additionally, we remain concerned that the plan to lower the doses in the ongoing late-stage study could meaningfully prolong development timelines." (Reporting by Anuradha Ramanathan and Anand Basu in Bangalore; Editing by Anil D'Silva)