Polyphor has enrolled the first patient in its FORTRESS Phase III clinical trial evaluating the efficacy, safety and tolerability of balixafortide (POL6326) and eribulin combination to treat patients with HER2 negative, locally recurrent or metastatic breast cancer (MBC).

The global, multi-centre, randomised FORTRESS (POL6326-009) trial will investigate the CXCR4 antagonist balixafortide administered with eribulin versus eribulin alone to treat HER2 negative MBC.

A total of 384 patients will be recruited for the active-controlled, open-label trial, with 320 participants receiving third or subsequent line chemotherapy and 64 being given second-line treatment.

Subject to the data, Polyphor is expected to submit a filing for accelerated approval about six months after concluding the recruitment on the basis of the analysis of the overall response rate (ORR).

Polyphor CEO Giacomo Di Nepi said: “The enrolment of the first patient in our Phase III clinical study is a significant step forward for the development of balixafortide.

“There is a significant unmet need for new treatment options for women with metastatic breast cancer who have failed initial standard-of-care chemotherapies. Developing a new treatment option will provide new hope for women with this devastating disease.

“We are hopeful that the response rates seen in our proof-of-concept study can be replicated in the FORTRESS trial and that balixafortide can make a positive impact on patient outcomes.”

The G-protein coupled receptor Balixafortide regulates the trafficking and homing of both cancer cells and cells of the patient’s immune system.

High CXCR4 expression is known to correlate with aggressive metastatic behaviour of cancer cells and a poor prognosis.