KX-02 is a closely related structural analog of KX-01 and demonstrates a similar dual MOA of inhibition of Src activity and microtubule polymerization. KX-02 was designed to readily cross the blood-brain-barrier, or BBB. The KX-02 levels in the mouse brain meet or exceed that in the plasma at the same time points after oral dosing, demonstrating that KX-02 readily crosses the BBB. We believe that this ability to cross the BBB provides a rationale for investigating brain cancers and metastases in the brain as potential therapeutic applications for what is traditionally considered an unmet medical need.
Based on pre-clinical data demonstrating activity against a number of brain cancer cell lines and demonstrated BBB penetration, KX-02 was tested orally in a mouse GBM tumor model, wherein the mice with a fully competent immune system are implanted with mouse GBM tumor cells into the brain in order to simulate a human patient. When compared with TMZ, the current standard of treatment, KX-02 produced long term survival mice, as compared to TMZ, which extended survival but did not result in any long term survivors. This data prompted the FDA to grant Orphan Drug Status to KX-02 for the treatment of gliomas.
We are currently enrolling a Phase 1 study in the U.S. of KX-02 for treatment of solid tumors in order to determine the MTD, PK, and safety profile. This trial is currently in the dose escalating phase. In 2012, we out-licensed KX-02 to Xiangxue Pharmaceuticals for development and marketing in greater China. The CFDA has approved the IND application for KX02 and clinical trials are currently being planned. As part of that collaboration, Xiangxue recently submitted an IND to the CFDA for subsequent clinical trials in China. We anticipate the development timeframe for our KX-02 drug candidate for glioblastoma to be accelerated once we commence our partnered clinical program in China.