BioClin Therapeutics, Inc. is developing B-701, a highly specific human anti-FGFR3 antibody, for metastatic bladder cancer (urothelial cell carcinoma) and achondroplasia (dwarfism).
B-701 is a human IgG1 monoclonal antibody that is highly specific for the FGFR3 receptor and does not cross-react with the other fibroblast growth factor receptors (FGFRs). It is being used to inhibit signaling through this pathway in bladder cancers that express wild-type or mutated FGFR3 and has potential for application in achondroplasia, the most common form of disproportionate dwarfism which is caused predominately by a single point-mutation in FGFR3.
Two Phase 1 clinical, open-label, dose-escalating studies have been conducted with patients receiving repeat intravenous injections of B-701. These include a Phase 1 study in patients with relapsed/refractory t(4;14)-positive multiple myeloma and a Phase 1 study in patients with advanced solid tumors, including relapsed/refractory metastatic bladder cancer. In these studies, B-701 was shown to be safe and generally well tolerated.
BioClin has initiated a Phase 2 clinical study investigating B-701 for the treatment of locally advanced or metastatic bladder cancer also known as urothelial cell carcinoma (UCC). The study will assess efficacy and safety study of B-701 in combination with docetaxel versus docetaxel alone in patients with Stage IV, locally advanced or metastatic UCC who have relapsed after, or are refractory to one or two prior lines of chemotherapy which have not included a taxane.
This study is divided into two phases: an open-label lead-in phase, which will assess the safety and early signal of efficacy of B-701 plus docetaxel, and a randomized, double-blind, placebo controlled phase, which will compare B-701 in combination with docetaxel vs. docetaxel. Details of this study can be found on www.clinicaltrials.gov.
Separately, a study testing B-701 in combination with a clinical-stage immune checkpoint inhibitor in patients with advanced/metastatic urothelial cell carcinoma is planned.
B-701 is in preclinical testing for achondroplasia for which FGFR3 antagonism may be beneficial. We completed a 6-month dosing study in juvenile monkeys and are conducting further studies to advance this program.