A Phase 3 trial is recruiting participants to examine the effects of sacituzumab govitecan in patients with metastatic triple-negative breast cancer (TNBC) who failed to respond, or relapsed after at least two prior treatments.

Patients are being recruited for the trial (NCT02574455) across several clinical sites in the United States, Canada, France, Belgium, Spain, the United Kingdom, and Germany. Participating centers in the U.S. can be found here.

Sacituzumab govitecan, made by Immunomedics, is a drug-conjugate compound that combines an antibody against the TROP-2 protein — found in many tumor types, including breast, colon, lung and prostate cancers — with a toxic payload. Once bound to its target, sacituzumab govitecan releases the toxic compound into cancer cells.

The treatment has already shown promise in metastatic TNBC patients who failed prior therapies, leading to partial or complete responses in 30% of patients included in a prior Phase 2 trial (NCT02161679).

In the trial, patients also remained alive and without disease progression for six months and lived an average of 16.6 months. The findings were significantly better than those of historical controls, who lived an average of 10 to 13 months and the disease progression ceased for only 3.5 months.

Based on findings from that trial, the U.S. Food and Drug Administration had already granted sacituzumab govitecan fast track designation for the treatment of TNBC patients who failed to respond to previous therapies.

The Phase 3 ASCENT trial is designed to confirm the findings in a larger population of patients. It will enroll approximately 490 patients who received at least two prior chemotherapies, including taxane. Patients will be chosen at random to receive sacituzumab govitecan or a standard treatment selected by the physician such as Halaven (eribulin), Xeloda (capecitabine), gemcitabine, or Navelbine (vinorelbine).

Sacituzumab govitecan will be infused on the first and eighth day of every 21-day cycle. Treatment will proceed unless toxicity levels are unacceptable, the disease worsens, or the patient withdraws from the trial or dies.

Participants will get computed tomography (CT) scans at least every six weeks for 36 weeks, and every nine weeks thereafter.

ASCENT’s primary goal is to determine if sacituzumab govitecan delays disease progression or death in these patients, compared with standard treatments. Overall survival, objective response rate, and duration of response will be assessed as secondary goals.