NEW YORK (GenomeWeb) – Tokai Pharmaceuticals said today it is working with Johns Hopkins University to develop a companion diagnostic for its investigational, castration-resistant prostate cancer (CRPC) drug galeterone.
Under its agreement, Cambridge, Mass.-based Tokai has garnered an exclusive, worldwide license from JHU for "patent applications and know-how" covering a test used to assess the AR-V7 status of prostate cancer patients.
According to Tokai CEO Jodie Morrison, the company will use the companion test in a 148-patient, Phase III ARMOR3-SV trial, slated to start in the first half of 2015. Tokai is developing galeterone for metastatic CRPC patients who express a truncated version of the androgen receptor, called AR-V7. Galeterone is designed to interrogate androgen receptor signaling, which drives prostate cancer.
Patients with truncated androgen receptors are missing the C-terminal end involved in ligand binding, and AR-V7 is the most frequently occurring splice variant that causes this terminal loss. A prospective JHU study, as well as retrospective analyses by MD Anderson Cancer Center and Memorial Sloan Kettering Cancer Center, suggests that patients with C-terminal loss and AR-V7 are poor responders to existing metastatic CRPC drugs such as Janssen Biotech's Zytiga (abiraterone acetate) and Astellas' Xtandi (enzalutamide).
Preclinical data generated by Tokai on galeterone, as well as a Phase II trial involving the drug, suggests that it may benefit CRPC patients with AR-V7 and C-terminal loss.
Tokai said it has also finalized an agreement with Qiagen for the development of a non-invasive companion diagnostic for galeterone "utilizing an array of novel technologies."