The US Patent and Trademark Office (USPTO) has issued a notice of allowance to KaloBios Pharmaceuticals for a composition of matter patent covering certain antibodies targeting EphA3, including its experimental anti-cancer monoclonal antibody (mAb), KB004. The allowed claims relate to high-affinity Humaneered antibodies to the EphA3 receptor.

Geoffrey Yarranton, Ph.D., KaloBios' chief scientific officer and co-inventor, commented, "EphA3 is a tyrosine kinase receptor that is expressed on hematologic cancers and solid tumors, including tumor stem cells, but not on normal blood or bone marrow stem cells. Targeting this antibody may therefore offer a way to selectively treat patients with hematologic malignancies who have become resistant or otherwise intolerant of standard chemotherapies."

KaloBios is currently conducting a phase I study of KB004 in hematologic malignancies and will be presenting interim data from that study at the 55th American Society of Hematology Annual Meeting and Exhibition on December 9, 2013. The phase I study of KB004 is a multi-centre, dose-escalation study evaluating KB004 in patients with advanced hematologic malignancies.  KaloBios plans to initiate the phase II portion of the study in acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) patients by the end of the year.

"This Notice of Allowance is a validation of the uniqueness of KB004 and our Humaneered technology incorporated into it. This is the third significant composition of matter patent for our proprietary product candidates, following US patents granted for KB001-A and KB003, all expiring in 2028 and beyond," said Don Joseph, KaloBios' chief legal officer.

KaloBios Pharmaceuticals, Inc. is developing a portfolio of proprietary, patient-targeted, first-in-class monoclonal antibodies designed to treat severe life-threatening or debilitating diseases for which there is an unmet medical need, with a clinical focus on severe respiratory diseases and cancer.