FPA008 is an antibody that inhibits colony stimulating factor-1 receptor (CSF1R) and it targets macrophages and monocytes, which are activated or elevated in multiple disease settings.
Five Prime chief medical officer Julie Hambleton said: "The expansion of our FPA008 program highlights the broad potential of targeting the CSF1 receptor pathway in a variety of therapeutic areas, and in mid-2015 we expect to have clinical development underway in eight disease settings.
"In the new Phase I/II trial in PVNS, we are evaluating our antibody in an orphan disease for which patients have few options beyond surgery.
"Our immuno-oncology clinical collaboration with Bristol-Myers Squibb will explore FPA008 in combination with the PD-1 immune checkpoint antibody, nivolumab, in a Phase Ia/Ib trial in non-small cell lung cancer, melanoma, head and neck cancer, pancreatic cancer, colorectal cancer and malignant glioma.
"Finally, our ongoing Phase I study is completing dosing in the open-label portion of the trial in rheumatoid arthritis patients."
During the Phase I dose escalation part of the trial, the company will evaluate the safety and pharmacodynamics of multiple ascending doses of FPA008 to determine the dose for expansion.
In the trial’s Phase II expansion phase, the company will evaluate response rate and duration, as well as measures of pain and joint function, in about 30 patients.
Initial data from the Phase I dose escalation portion of the trial is expected to be reported by late 2015 or early 2016.
The company is also developing FPA008 in PVNS, an orphan disease driven by the CSF1R pathway, and is completing the open-label part of a Phase I trial in RA patients.