Arrowhead Research Corp.’s trading day started with a bang when sunny research results released ahead of a Thursday investor and analyst meeting sent shares soaring more than 44 percent to $9.97 in pre-market trading.

The Pasadena biopharmaceutical firm revealed that its most advanced lead drug candidate, meant to treat chronic hepatitis B virus infections, had greatly reduced the disease in humans and chimpanzees.

In a phase-2a study of the drug, ARC-520, human patients treated with a single dose showed up to a 98 percent reduction in the circulation of a viral protein produced by hepatitis B infected cells. In the long-term study of chimps, the animals saw an 81 percent to 99 percent reduction in viral proteins.

“It validated the technology for us, which was very important,” said Arrowhead Chief Operating Officer Dr. Bruce Given while discussing the human results during the presentation. He added that the firm was “really gratified” to see there hadn’t been any issues from a safety perspective.

Though Arrowhead shares soared dramatically in early trading, they ended the day up a more modest 6.7 percent, closing at $7.19.