OUTLINE: This is a multicenter study. Patients receive monoclonal antibody HuG1-M195 (MOAB HuM195) IV over 4 hours on days 1-4 every 2 weeks for 4 courses. Patients without disease progression after completion of course 4 continue to receive MOAB HuM195 as above. Treatment repeats every month for a maximum of 8 additional courses in the absence of disease progression or unacceptable toxicity. Patients are followed every 3 months.