Provided herein are B cell maturation agent (BCMA) targeting trispecific proteins comprising a domain binding to CD3, a half-life extension domain, and a domain binding to BCMA. Also provided are pharmaceutical compositions thereof, as well as nucleic acids, recombinant expression vectors and host cells for making such BCMA targeting trispecific proteins. Also disclosed are methods of using the disclosed BCMA targeting trispecific proteins in the prevention, and/or treatment diseases, conditions and disorders.
