Celldex Therapeutics, Inc., a biopharmaceutical company, engages in developing therapeutic monoclonal and bispecific antibodies for the treatment of various diseases. Its drug candidates include antibody-based therapeutics to treat patients with inflammatory diseases and various forms of cancer. The company's clinical development programs CDX-0159, a Phase I monoclonal antibody that binds the receptor tyrosine kinase KIT and inhibits its activity; CDX-1140, a human agonist monoclonal antibody targeted to CD40, a key activator of immune response, which is found on dendritic cells, macrophages, and B cells, as well as is expressed on various cancer cells; and CDX-527, a bispecific antibody, which uses the company's proprietary active anti-PD-L1 and CD27 human antibodies to couple CD27 costimulation with blockade of the PD-L1/PD-1 pathway to help prime and activate anti-tumor T cell responses through CD27 costimulation.