MTV axed the late-night relationship talk show "Loveline" yesterday after four years and 369 episodes, causing one of its producers, Scott A. Stone, to be "thrown for a loop," reports Variety. He said no reason was given for the cancellation, and though ratings were never high for the half-hour show, its recent numbers remained essentially the same as they'd always been. Hosts Dr. Drew Pinsky, Adam Carolla and Catherine McCord, as well as the occasional celebrity guest, discussed sex issues with young adults in the audience and on the phone on the series, which will continue to be produced in its nationally syndicated radio version.