Vion Pharmaceuticals Inc., of New Haven, Conn., appointed Ian Williams to its board.

Xenome Ltd., of San Diego, appointed Richard DiMarchi, John Wood and Alan Robertson to its scientific advisory board.

Xoma Ltd., of Berkeley, Calif., promoted Patrick Scannon to executive vice president and chief biotechnology officer.

XTL Biopharmaceuticals Ltd., of New York, appointed Bill Kessler principal financial and accounting officer.