KaloBios commences KB004 Phase 1 trial in patients with leukemia

KaloBios Pharmaceuticals, Inc., a privately held biopharmaceutical company, today announced treatment of the first patient in a Phase 1 clinical trial of KB004, its first-in-class Humaneered™ monoclonal antibody, in EphA3-expressing hematologic malignancies.

EphA3 is an onco-fetal protein that is expressed in a range of cancers, including hematologic malignancies and possibly on leukemic stem cells. A team of Australian collaborators, including Dr. Martin Lackmann of Monash University, Melbourne; Dr. Andrew Boyd of Queensland Institute of Medical Research and the University of Queensland, Brisbane, who originally isolated the KB004 precursor monoclonal antibody, IIIA4; and Dr. Andrew Scott of Ludwig Institute for Cancer Research, Melbourne, realized the potential of EphA3 as an anti-cancer target and, in a series of animal studies, evaluated the IIIA4 antibody as an anti-cancer agent.

"We are excited to see progression of KB004 into the clinic, as we believe this antibody could provide significant benefit to patients with a broad array of cancer types, given its potential to kill tumors through several distinct mechanisms," said Dr. Lackmann.

"KB004's unique ability to target and activate EphA3 and its similarity to the human germ-line sequences could result in measurable efficacy and low immunogenicity," said Dr. Boyd. "As a hematologist, I am particularly pleased that the first trial is in patients with leukemia."

"KB004 is a patient-targeted, potentially disease-modifying antibody that has shown encouraging preclinical proof-of-concept results that we hope will translate into the clinical setting for leukemias," said Jeffrey E. Lancet, MD of Moffitt Cancer Center of Tampa, Florida who treated the first patient. MD Anderson Cancer Center of Houston, Texas is also participating in the study.

The multi-center, open-label Phase 1 trial is being conducted in patient populations with EphA3-positive hematologic malignancies, including chronic myelogenous leukemia, acute myelogenous leukemia, acute lymphocytic leukemia, and myelodysplastic syndromes, who are refractory to, have failed, or have not received standard-of-care treatment. Patients older than age 65 who are not considered medically suitable for standard-of-care are also eligible. In the dose-escalation phase of the trial, up to 24 patients that have been prospectively screened for the presence of EphA3 will receive one of four dose levels, once weekly for three weeks for a maximum of 17 treatment cycles. Once the escalation phase is complete, an expanded phase of the trial will be initiated with up to an additional 15 patients. The primary endpoint of the trial is the determination of the maximum tolerated dose; secondary endpoints include safety, tolerability, pharmacokinetics, pharmacodynamics, immunogenicity and clinical activity.