Immunomedics’ Trodelvy Successful in Phase III Breast Cancer Study

Immunomedics announced today that its Phase III study involving Trodelvy met its primary endpoint of progression-free survival (PFS), as well as secondary endpoints, in patients with metastatic triple-negative breast cancer (mTNBC) who have previously received at least two prior therapies.

Trodelvy, also known as sacituzumab govitecan-hziy, was recently approved by the U.S. Food and Drug Administration (FDA) as a third-line treatment for adults with mTNBC under its Accelerated Approval Program.

In the Phase III study, known as ASCENT, Trodelvy showed a statistically significant improvement in the primary endpoint of PFS compared to chemotherapy. The median PFS for patients who received the drug was 5.6 months, compared to 1.7 months for those who underwent chemotherapy.

“The results of the global Phase III ASCENT study confirm our initial observations that sacituzumab govitecan has the potential to change the standard management of mTNBC,” said the study’s principal investigator, Aditya Bardia, MD, MPH, Director of Precision Medicine at the Center for Breast Cancer, Mass General Cancer Center and Assistant Professor of Medicine at Harvard Medical School. “Based on these data, sacituzumab govitecan has set a new benchmark in scientific and clinical innovation for patients with mTNBC by offering a novel alternative to the common drugs currently in clinical practice. Importantly, the ASCENT topline data also validate the manageable safety profile of sacituzumab govitecan, rendering it a good partner candidate for combination with other therapies, including immunotherapy.”

ASCENT was an international, open-label confirmatory Phase III trial that enrolled more than 500 patients. In addition to its primary endpoint of PFS, its secondary endpoints included overall survival, objective response rate, duration of response, time to onset of response, and other safety and tolerability measuring points.

In April, Immunomedics announced that it would be stopping ASCENT as a result of compelling efficacy. This was based on a unanimous recommendation by the Data Safety Monitoring Committee during its recent routine review.

“It is gratifying to see the final confirmatory results of Trodelvy in a randomized study supporting the previously reported Phase II data that formed the basis of the accelerated approval of Trodelvy. These results provide important additional information for patients and their treating physicians to understand the definitive benefits they are deriving,” said Dr. Behzad Aghazadeh, Executive Chairman of Immunomedics. “Importantly, the strong ASCENT data reinforce the promise of our unique ADC technology and embolden us to continue our work to change the treatment paradigm for patients with difficult-to-treat cancers.”

As of late, Immunomedics has been exploring the use of Trodelvy for other indications, including metastatic urothelial cancer (mUC). The company announced in May that Trodelvy showed clinical activity in cisplatin-ineligible patients with mUC, as well as in patients with previously-treated metastatic endometrial cancer (mEC).

“Trodelvy is now being developed for a broad spectrum of epithelial cancers, either independently or in close collaboration with key opinion leaders and corporate partners,” said Dr. Loretta M. Itri, Chief Medical Officer, at the time of the announcement.

Preclinical studies have shown Trodelvy to have activity against chemotherapy-resistant endometrial cancer and significant bystander effect against endometrial cancer with heterogenous Trop-2 expression.

Trodelvy has a black box warning for severe neutropenia and severe diarrhea. The most common adverse reactions that occur in 25% or more of patients include nausea, neutropenia, diarrhea, fatigue, anemia, vomiting, alopecia, constipation, decreased appetite, rash and abdominal pain.