Abstract: The present disclosure provides compositions and methods for improved pre-targeted radioimmunotherapeutics (PRIT) to treat various hematological disorders, such as B cell hyperproliferative disorders and solid tumors. The disclosed compositions include bispecific antibody compositions having a first domain that specifically bind to an antigen such as CD38, BCMA, Muc1, GPRC5D, or Slam7 and a second domain that specifically binds to a radioactive ligand. Methods include administering the disclosed bispecific antibody reagent and separately administering the radioactive ligand. In some embodiments, a clearing agent is also administered. In some embodiments, the therapeutic methods comprise administering a combination of two or more bispecific antibody reagents. In some embodiments, an enhancing agent, such as ATRA, gamma secretase inhibitor, or dextramethasone, is also administered to enhance expression of the target antigen on the target cells.