FPA144 is an anti-FGF receptor 2b (FGFR2b) humanized monoclonal antibody in clinical development as a targeted immune therapy for tumors that over-express FGFR2b. We estimate approximately 10% of gastric cancer patients have tumors that overexpress the FGFR2b protein, which is associated with poor prognosis.
FPA144 is designed to block tumor growth through two distinct mechanisms:
- First, it binds specifically to FGFR2b and prevents the binding of certain fibroblast growth factors that promote tumor growth.
- Second, it has been engineered to drive immune-based killing of tumor cells by antibody-dependent cell-mediated cytotoxicity (ADCC) through the recruitment of natural killer (NK) cells.
Preclinical studies have shown that FPA144 is highly effective in blocking the growth of gastric cancers that produce abnormally high levels of FGFR2b. Preclinical studies in models of gastric cancer have also shown that FPA144 has additive activity in combination with chemotherapy.
In May 2017, we announced updated data from the ongoing Phase 1 trial in FPA144 in an abstract submitted to the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting.
We initiated a Phase 1 clinical trial for FPA144 at the end of 2014. The Phase 1 trial initially enrolled unselected patients with solid tumors and is now enrolling selected gastric cancer patients with FGFR2 gene-amplified or FGFR2b protein overexpressing tumors. FPA144 is a targeted antibody and we plan to use companion diagnostic tests that detect protein overexpression or gene amplification to identify eligible patients for our clinical trials.
While we have shown monotherapy activity in gastric cancer, we believe combination therapy will provide the greatest patient benefit. We plan to initiate a chemotherapy combination gastric cancer trial to move into the front-line treatment of metastatic gastric cancer.
Additionally, we received approval from the PMDA in Japan to initiate a Phase 1 monotherapy study in patients with gastric cancer, and are on track to begin this study in late 2017.
In July 2016, the U.S. Food and Drug Administration (FDA) granted FPA144 Orphan Drug Designation for the treatment of gastric cancer, including cancer of the gastroesophageal junction.
Globally, gastric cancer is the sixth most common malignancy with the third highest mortality. The prevalence of gastric cancer worldwide is approximately 1.5 million patients, of which an estimated 10%, or approximately 150,000 patients, have FGFR2 gene-amplified tumors that overexpress FGFR2b. There are an estimated 76,000 gastric cancer patients in the United States and between 16,000 and 17,000 progress to advanced gastric cancer and are eligible for treatment with front-line chemotherapy each year. The prevalence of gastric cancer is much higher in Asia and other regions of the world, for example, Decision Resources Group estimates that almost 73,000 patients are eligible for front-line chemotherapy treatment in Japan each year.
Beyond the gastric cancer setting, we are also studying FPA144 in patients with bladder cancer. We added a cohort to the current Phase 1 clinical trial to evaluate FPA144 in patients with bladder cancer whose tumors overexpress FGFR2b.
According to our research, approximately 14% of tumor samples from patients with metastatic bladder cancer overexpress FGFR2b as assessed by our immunohistochemistry (IHC) test.