CD200 and B-cell chronic lymphocytic leukemia: This is a first-in-human phase I trial to evaluate the safety, pharmacokinetics (PK), pharmacodynamic (PD), and anti-tumor activity of CD200 blockade with samalizumab in patients with CLL and MM, and to identify the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of samalizumab.