Study of a New Drug, Sacituzumab Tirumotecan, Given Alone or in Combination with an Immunotherapy for Metastatic, Triple-Negative Breast Cancer (TroFuse-011)

About the Study

This study is testing a new targeted therapy, sacituzumab tirumotecan, given alone or with the immunotherapy Keytruda (pembrolizumab) to treat triple-negative, metastatic breast cancer (TNBC). Keytruda is an immunotherapy that is FDA approved to treat TNBC. The goal of the study is to learn how well sacituzumab tirumotecan can cause tumors to shrink or disappear and how long that response lasts.

What the Study Involves

The study has three participant groups.

Participants will be selected by chance to participate in one of three groups.

• Group 1: People will receive sacituzumab tirumotecan by IV every 2 weeks until the cancer returns or grows.
• Group 2: People will receive sacituzumab tirumotecan by IV every 2 weeks until the cancer returns or grow. They will also receive pembrolizumab by IV every 6 weeks for up to 2 years.
• Group 3: People will be given a chemotherapy treatment of their physician’s choice. Either:
  • Paclitaxel by IV once every week OR days 1, 8 and 15 every 4 weeks
  • Nab-paclitaxel by IV on days 1, 8 and 15 every 4 weeks
  • Gemcitabine plus carboplatin by IV on days 1 and 8 every 3 weeks

All participants will be asked to complete a questionnaire covering several quality-of-life-related topics. The study team will monitor the participants' progress and check for any side effects for up to 61 months.

Study treatment will continue until the cancer progresses, side effects are too severe or the person decides to stop.

This study is open to people diagnosed with metastatic triple-negative breast cancer, who:

• Are 18 years and older.
• Have not received treatment for metastatic breast cancer. 
• Finished treatment for early-stage TNBC at least 6 months before the cancer returned.
• Are able to receive treatment with pembrolizumab and one of the standard chemotherapy options: paclitaxel, nab-paclitaxel or gemcitabine plus carboplatin.
• Side effects from previous treatments should have improved or be under control.
• Have reasonable control of the virus if they have the hepatitis B virus (HBV) or the hepatitis C virus (HCV).

People are not eligible for the study if they:

• Have breast cancer that can still be cured with treatment.
• Have a tumor with biomarker testing of PD-L1 levels with a combined positive score (CPS) of 10 or higher.
• Have already received treatment for TNBC that has come back, cannot be removed by surgery, or is metastatic.
• Have moderate or severe peripheral neuropathy.
• Have a history of certain eye conditions, autoimmune illness or heart conditions.
• Their disease has metastasized to the skin only.
• They have human immunodeficiency virus (HIV) and a history of Kaposi’s sarcoma and/or Multicentric Castleman’s disease.
• Have had another cancer in the past 5 years
• Previously received stem cell or solid organ transplant.
• Have not fully recovered from previous surgery or its complications.