Updates shares, adds details from call in paragraphs 5, 7, and analyst comment in paragraph 8

By Kamal Choudhury

Dec 3 (Reuters) - Capricor Therapeutics CAPR.O said on Wednesday its cell therapy for a rare muscular disorder met the main goal of a late-stage study, reviving hopes for U.S. approval after a setback and sending its shares up more than four-fold.

Shares of the San Diego-based company soared 328% to $27.25, on track to add about $955 million in market value, if gains hold.

In July, the U.S. Food and Drug Administration had declined to approve the therapy, deramiocel, as it sought additional data after saying the treatment did not meet efficacy requirements.

Capricor said it plans to use the new results in its response to the agency's so-called "complete response letter." It had previously agreed with the FDA that this trial could support approval of its treatment for patients with Duchenne muscular dystrophy.

The FDA has indicated it would be a class 2 resubmission with about a six-month timeline, CEO Linda Marbán told analysts, adding that the company would seek a rapid review.

In the 106-patient trial, those given deramiocel saw a 54% slower decline in upper limb function versus placebo, while there was a 91% slower worsening of heart function, both statistically significant, the company said. The therapy was generally well tolerated.

The company said it has addressed chemistry, manufacturing and control requirements and passed a pre-licensing inspection for its San Diego commercial manufacturing facility.

B. Riley Securities analyst Madison El-Saadi said he expects the treatment to get approved as the data delivered an "unambiguous efficacy signal" across all trial goals.

Duchenne, a rare genetic disorder that causes muscle degeneration, affects fewer than 50,000 people in the U.S., according to the National Institutes of Health. Heart complications are the leading cause of death in patients, typically in the twenties or thirties.

(Reporting by Mariam Sunny and Kamal Choudhury in Bengaluru; Editing by Shinjini Ganguli and Leroy Leo)

((Mariam.ESunny@thomsonreuters.com;))