The present invention generally provides methods for B-cell reduction in an individual using CD37-specific binding molecules. In particular, the invention provides methods for B-cell reduction using CD37-specific binding molecules alone, or a combination of CD37-specific binding molecules and CD20-specific binding molecules, in some instances a synergistic combination. The invention further provides materials and methods for treatment of diseases involving aberrant B-cell activity. In addition, the invention provides humanized CD37-specific binding molecules.
