Seattle Genetics, Inc. has announced encouraging clinical data from denintuzumab mafodotin in B-cell malignancies, including diffuse large B-cell lymphoma, or DLBCL, and B-lineage acute lymphocytic leukemia, or B-ALL. Preclinical data from a novel antibody-drug conjugate (ADC) program called SGN-CD19B in B-cell malignancies will also be presented. About 85% of non-Hodgkin lymphomas (NHL) are B-cell lineage, and CD19 is broadly expressed across all subtypes of B-cell malignancies.

These two ADCs, 19A and SGN-CD19B, both target CD19 and utilize two of Seattle Genetics' proprietary payloads, monomethyl auristatin F (MMAF) and a pyrrolobenzodiazepine (PBD) dimer, respectively. The company has initiated the first of two planned Phase II trials of 19A in DLBCL and plans to advance SGN-CD19B into a Phase I trial in 2016.