 - Treatment Arm A: Oral Chlorambucil 0.5 mgkg on Days 1 and 15 of each 28-day cycle; the dose can be increased, if well tolerated, in increments of 0.1 mgkg on Day 1 of each cycle to a maximum of 0.8 mgkg; patients receive a minimum of 3 and a maximum of 12 cycles, in the absence of progressive disease or unacceptable toxicity. 