The program also includes FPA008 which is in its initial development stage for immunology as well as oncology indications.
Under the terms of the agreement, Five Prime will receive a $350m upfront payment from Bristol-Myers Squibb which would be responsible for development and manufacturing of FPA008 for all indications.
Five Prime will continue to conduct the current phase Ia/1b trial evaluating the combination of Opdivo and FPA008 in six tumor settings.
The company will also receive up to $1.05bn in development and regulatory milestone payments per anti-CSF1R product for oncology indications, and up to $340m in development and regulatory milestone payments.
The latest agreement replaces the existing clinical collaboration agreement of the companies to assess the safety, tolerability and preliminary efficacy of combining Bristol-Myers Squibb’s programmed-death 1 (PD-1) immune checkpoint inhibitor Opdivo (nivolumab), with FPA008 in six tumor types.
Bristol-Myers Squibb executive vice president and chief scientific officer Francis Cuss said: "By blocking a key mediator of immunosuppression in the tumor microenvironment, CSF1R inhibition with FPA008 represents a potentially important complementary immuno-oncology mechanism of action to the T-cell directed antibodies and co-stimulatory molecules in our pipeline.
"This agreement, which builds upon our existing relationship with Five Prime in immuno-oncology, is another important example of our commitment to expanding our presence in this space and to researching novel combination regimens."
Five Prime Therapeutics president and CEO Lewis "Rusty" Williams "said: "We believe this transformational collaboration with Bristol-Myers Squibb for our CSF1R antibody program represents the best of both worlds in terms of maximizing the potential of FPA008."
The investigational antibody FPA008 inhibits CSF1R and has been shown in preclinical models to block the activation and survival of monocytes and macrophages.
Opdivo, which currently has regulatory approval in over 37 countries, is indicated for patients with unresectable or metastatic melanoma.
Image: A research campus operated by Bristol-Myers Squibb in Princeton, New Jersey. Photo: courtesy of Coolcaesar