FCRL5 x Tubulin

This multicenter, open-label, dose-escalating study will assess the safety and efficacy of DFRF4539A in patients with relapsed or refractory multiple myeloma. Cohorts of patients will receive multiple ascending doses of intravenous DFRF4539A every 3 weeks or weekly. Patients exhibiting acceptable safety and evidence of clinical benefit may receive DFRF4539A for up to 17 cycles. Anticipated time on study treatment is 1 year or until disease progression or unacceptable toxicity occurs.