Five Prime, Bristol Pancreatic Cancer Drug Combo Fails Phase 2 Test

Xconomy San Francisco — 

A year ago Five Prime Therapeutics cut a fifth of its workforce to save money as its worked to advance its clinical-stage drugs for solid tumor cancers.

On Tuesday the company (NASDAQ: FPRXsaid one of those drugs, cabiralizumab, a Five Prime antibody that Bristol-Myers Squibb (NYSE: BMY) was testing in combination with its cancer immunotherapy nivolumab (Opdivo), failed to beat the standard of care in a Phase 2 trial in patients with pancreatic cancer.

Cabiralizumab blocks a protein called colony-stimulating factor-1 (CSF1R) in an effort to stymie the activation and survival of monocytes and macrophages. In preclinical tests in models of several cancers, inhibiting CSF1R facilitated an immune response against tumors by reducing the number of immunosuppressive tumor-associated macrophages in the tumor microenvironment. Bristol-Myers Squibb paid Five Prime $350 million up front in 2015 to license cabiralizumab and collaborate on multiple trials evaluating the drug.

The Phase 2 trial enrolled about 160 patients with locally advanced or metastatic pancreatic cancer whose disease has progressed during or after one chemotherapy treatment. Patients were randomly assigned to receive either the combo or chemotherapy. But the combination didn’t meet the trial’s primary goal, although no details on the data were provided, and the companies did not indicate whether they would be presented.

The South San Francisco-based biotech said BMS, which acquired rights to cabiralizumab as part of the deal inked in 2015, has no plans to sponsor additional development of the investigational drug. It wasn’t immediately clear whether the New York pharma giant plans to continue the other trials evaluating the drug. Xconomy has reached out to the company for more information and will update with its response.

Five Prime stock wasn’t much impacted by the failure, remaining relatively unchanged at $4.42 apiece as of Tuesday’s market close compared to $4.53 per share Friday. (Markets were closed Monday in recognition of Presidents’ Day.)

Since the cuts in January 2019 Five Prime has continued to experience money woes. In October the company initiated a major restructuring, with plans to cut 70 more positions and sublet a significant portion of its facilities, according to filings with securities regulators.

At the time, the company anticipated eliminating most of its in-house target discovery and validation and protein therapeutic generation and engineering capabilities by this quarter, moves it estimated would save an annualized $20 million. That means Five Prime is now counting on the antibodies it has already discovered to keep it moving ahead.

The biotech’s most advanced program is evaluating bemarituzumab, an antibody designed to block tumor growth in patients with tumors that overexpress FGFR2b. Five Prime is studying the drug, in partnership with Zai Lab, in a Phase 3 trial in combination with chemotherapy in patients with gastric cancer. Data from that trial is anticipated midyear.

The company reported a net loss of $105.8 million in the first nine months of 2019, and $101.7 million in the same months the year prior. Five Prime last year said it anticipated ending 2019 with $148 million to $153 million in cash and equivalents on hand.