CytRx Corporation (Nasdaq: CYTR), a biopharmaceutical company specializing in oncology, today announced that results from a series of preclinical studies demonstrating that its oncology drug candidate bafetinib inhibits bone destruction in model systems is being presented on April 2, 2011 at the American Academy for Cancer Research (AACR) 102nd Annual Meeting in Orlando, Florida.
Dr. James R. Berenson, Medical & Scientific Director of the Institute for Myeloma & Bone Cancer Research, commented, "As recently reported, our research shows that bafetinib, even in low concentrations, significantly inhibited the cells that cause bone destruction that can lead to devastating consequences in cancer patients such as fractures, bone pain and hypercalcemia. I believe that bafetinib certainly warrants additional study in this area."
The abstract, titled "The tyrosine kinase inhibitor bafetinib (INNO-406) inhibits osteoclast formation and bone resorption," is based on a series of preclinical studies evaluating the effect of bafetinib on bone cells (osteoclasts) from multiple myeloma patients. Osteoclasts are multinucleated bone-resorbing cells derived from monocytes that play critical roles in bone remodeling. Prior studies indicated that Lyn and Fyn kinases have negative impacts on osteoclasts, thus potentially reducing bone resorption. Bafetinib is an inhibitor of Bcr-Abl, Fyn and Lyn kinases, which prompted these initial studies in bone loss and bone resorption.
To evaluate the effects of bafetinib on osteoclast formation and bone resorption, monocytes derived from multiple myeloma patients and normal subjects were stimulated to form osteoclasts and at the same time were treated with bafetinib. As a parallel, the same type of cells were treated with zoledronic acid (Zometa), an inhibitor of osteoclast formation and bone resorption currently used to prevent skeletal complications for patients with multiple myeloma, metastatic bone diseases or osteoporosis. Bafetinib and zoledronic acid both markedly inhibited osteoclast cell formation at similar concentrations in both multiple myeloma and normal monocytes. An additional in vitro study demonstrated that bafetinib reduced osteoclast formation by blocking the pathway leading to monocyte transformation. In other experiments, bafetinib, even at low concentrations, significantly inhibited bone resorption in a concentration-dependent fashion.
CytRx President and CEO Steven A. Kriegsman said, "We see a significant opportunity with bafetinib's ability to block several of the kinases involved in bone resorption as well as cancer cell growth. Several cancers have a high incidence of bone metastases, and bafetinib may be an important therapy, either alone or in combination with other agents, to treat theses types of tumors."
CytRx is currently evaluating bafetinib in three ongoing clinical trials: the ENABLE Phase 2 proof-of-concept clinical trial in patients with a late-stage form of leukemia known as high-risk B-cell chronic lymphocytic leukemia; a pharmacokinetic clinical trial in patients with recurrent brain tumors; and the PROACT Phase 2 proof-of-concept prostate cancer clinical trial in patients with advanced prostate cancer.