mCRPC – Few Treatment Options

BPX-101 is initially for the treatment of patients with metastatic castrate resistant prostate cancer (mCRPC), with potential expansion into earlier stages of the disease and other cancers expressing the target antigen, Prostate Specific Membrane Antigen (PSMA), which may be a ubiquitous anti-vasculature target for most other solid tumors.

In the United States, prostate cancer is the most common solid tumor malignancy in men. It was expected to account for an estimated 192,280 new cases of prostate cancer in 2009 and 27,360 deaths. Approximately 70% of patients who experience PSA progression after primary therapy will have metastases at some time during the course of their disease. Androgen deprivation therapy (ADT) is the standard therapy for metastatic prostate cancer and achieves temporary tumor control or regression in 80-85% of patients.

Despite hormonal therapy, virtually all patients with metastatic prostate cancer ultimately develop progressive disease. Most patients with prostate cancer who have been started on ADT are treated for a rising PSA after failure of primary therapy. In the absence of clinical (i.e. measurable) metastases, these patients experience a relatively long disease-free interval in the range of 7-11 years, but the majority eventually develops hormone-resistant disease as evidenced by the return of a rising PSA level in the face of castrate levels of serum testosterone. These advanced patients have a poor prognosis, with the majority developing clinical metastases within 9 months and a median survival of 16 to 24 months. Approved treatment options include Provenge™ (sipuleucel-T), Taxotere® (docetaxel) and Jevtana® (cabazitaxel), but none offer more than a 4.1 increase in median overall survival.