Providence Cancer Institute is currently enrolling people with triple-negative breast cancer in a phase III clinical trial investigating a promising new treatment combination for this difficult-to-treat form of breast cancer. The randomized study could offer better outcomes for people who remain at high risk after standard therapy.
Triple-negative breast cancer (TNBC) is an aggressive subtype representing 10% to 15% of all breast cancers. Eligible participants must meet a very specific clinical profile:
- Diagnosed with high-risk, early-stage TNBC (Stage II or III)
- Received standard neoadjuvant therapy (chemotherapy plus pembrolizumab)
- Did not achieve a pathological complete response (pCR) — meaning cancer cells remained in the body at the time of surgery
Patients who do not achieve pCR face significantly worse outcomes. Studies show their 5-year event-free survival and overall survival rates are approximately 56.6% and 63.4%, respectively, compared to 85.5% and 87.9% for patients who do achieve pCR. This reflects a clear and urgent need for better options for this group.
If you or a loved one may be eligible, talk to your oncologist or contact Providence Cancer Institute.
What the trial is testing
Approximately 1,530 participants will be randomly assigned to one of two treatment arms:
Arm 1: MK-2870 plus pembrolizumab (immunotherapy)
Arm 2: Pembrolizumab alone, or pembrolizumab plus capecitabine (standard of care)
The primary goal is to determine whether MK-2870 combined with pembrolizumab improves invasive disease-free survival (the time before cancer returns or death occurs) compared to current standard treatment.
How MK-2870 works
MK-2870 is an antibody-drug conjugate (ADC), a precision medicine that acts like a guided missile, combining the targeting ability of an antibody with the cancer-killing power of chemotherapy.
Here's how it works:
Target identification: MK-2870 seeks out TROP2, a protein highly expressed on TNBC tumor cells but present at low levels in normal tissue. In one study, 93% of TNBC samples showed strong TROP2 expression.
Binding and internalization: The antibody locks onto TROP2, and the entire complex is pulled inside the cancer cell.
Payload release: Once inside, the cytotoxic drug (KL610023) is released, causing cancer cell death. MK-2870 also triggers bystander activity to kill neighboring tumor cells.
By pairing MK-2870 with pembrolizumab, the trial aims to harness both the targeted cell-killing of the ADC and the immune system-activating power of immunotherapy. The combination has shown early promise in other studies.
Why this matters
Earlier phase studies of MK-2870 in metastatic TNBC showed encouraging results, with an overall response rate of 40% and a disease control rate of 80% in previously treated patients. In a phase III study comparing MK-2870 to chemotherapy, MK-2870 demonstrated significantly improved progression-free and overall survival.
If this trial confirms those results in the early-stage setting, MK-2870 plus pembrolizumab could become a new standard of care for high-risk TNBC patients who don't respond fully to initial treatment.
Get more information
Providence Cancer Institute has two sites in Oregon enrolling patients in this study. David B. Page, M.D., is the principal investigator. Find out more:
MK-2870 Plus Pembrolizumab Versus TPC in TNBC Who Did Not Achieve pCR
To refer a patient:
- Call 503-215-1979
- Send an email
Find out about other clinical trials at Providence Cancer Institute.
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