Shares of biopharmaceutical company Arrowhead Research Corp. rose 1.1 percent to $8 Monday on news that the Food and Drug Administration has greenlit a new clinical study of the Pasadena firm’s most advanced drug candidate.

“We are working diligently to get treatment sites up and running,” Dr. Bruce Given, Arrowhead’s chief operating officer and R&D head, said in a statement. He said the firm hoped to begin recruiting and enrolling patients in about a month for the multiple-dose Phase 2b study of the company’s hepatitis B treatment, ARC-520.

“We are also working with various regulatory agencies outside of the United States to initiate additional Phase 2b studies,” the statement said.

The trial primarily aims to evaluate the decline of hepatitis B in patients with a chronic, immune active version of the virus when treated with multiple doses of ARC-520. Arrowhead develops targeted drugs that silence disease-causing genes.

Arrowhead’s trial hit a speed bump in January when the FDA asked the firm not to test a higher dosage of the drug in this study, and instead only proceed with a test of a lower dose than proposed. That news caused the stock price to plummet to $6.90 from a previous bump to $9.06, which had been triggered by speculation the company was a takeover target for Gilead Sciences Inc. of Foster City.