ArQule shares jump after positive drug update

NEW YORK (AP) -- Shares of ArQule Inc. soared in afterhours trading Thursday after the specialty drugmaker reported that a committee of safety monitors said its liver cancer study of tivantinib could continue using a lower dose of the drug.

THE SPARK: ArQule said in a statement that the safety committee recommended continuing the trial using a lower dose of tivantinib to prevent cases of neutropenia, which causes abnormally low white blood cells. Patients in the study have been subject to extra safety monitoring measures since September due to reports of the side effect.

THE BIG PICTURE: ArQule and its partner Daiichi Sankyo of Japan have been studying tivantinib as a treatment for several cancers, including colorectal cancer and non-small cell lung cancer. The drug works by blocking an enzyme that, when inappropriately activated, can cause cancer cells to grow, spread and live longer.

Tivantinib is ArQule's most advanced drug, and it has faced several recent setbacks. Last week, the companies reported that tivantinib did not meet its main goal for survival without tumor growth in a mid-stage study in colorectal cancer patients. In 2012, the companies stopped enrolling new patients in a late-stage study of tivantinib as a treatment for non-small cell lung cancer. At the time, the study's safety monitoring committee said patients who were being treated with tivantinib and Tarceva, another cancer drug, were not living longer than patients treated with Tarceva and a placebo.

SHARE ACTION: Shares of ArQule Inc. rose 62 cents, or 26 percent to $2.98 in afterhours trading Thursday, after closing the regular trading session $2.36.