Recruiting

Testing a new cancer drug for breast cancer with specific genetic mutations

Plain-English translation of NCT03990896 on ClinicalTrials.gov ↗ · Source last updated May 2026 · Translation generated August 2026 · How we translate trials

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Phase 2 — Testing in a bigger group (up to a few hundred people) to see if the treatment actually works and is still safe.

What is this trial?

This trial is testing a medication called to see if it can treat advanced breast cancer in people whose tumors have specific genetic mutations (changes in BRCA genes). works by blocking proteins that help cancer cells repair their DNA damage, which may cause the cancer cells to die. Early research suggests this type of medication can shrink tumors and slow cancer growth in some patients with these genetic changes.

While this medication has been approved for some inherited BRCA mutations, researchers want to learn whether it works for people whose tumors have acquired (non-inherited) BRCA mutations. This trial will help doctors understand if the treatment is effective and safe for this specific group of patients.

Do you qualify?

You likely qualify if…

you have been diagnosed with advanced (metastatic) breast cancer with a somatic BRCA1 or BRCA2 mutation detected in your tumor's circulating DNA
your cancer is either triple-negative breast cancer that has grown despite at least one prior chemotherapy, or hormone receptor positive disease that has progressed on prior endocrine therapy
you have measurable or evaluable disease that doctors can track during the trial
you are at least 18 years old and in good enough overall health to tolerate treatment
your blood work and organ function (liver, kidneys, bone marrow) are adequate for safe treatment

You likely don't qualify if…

you have an inherited (germline) BRCA mutation rather than a mutation only in your tumor
you have progressed while on platinum-based chemotherapy or within 6 months of completing it
you have severe side effects from your most recent cancer treatment that have not recovered to mild levels
your liver, kidney, or bone marrow function is too compromised to handle the medication safely

What participation looks like

As a participant, you would take by mouth in capsule form every day. You would need to have blood work and imaging scans done regularly to monitor how your cancer is responding and to check for any side effects. The trial involves about 30 participants total, and you would work closely with your medical team at Massachusetts General Hospital or a participating site to ensure the treatment is working and is tolerable for you.

AI-generated summary from trial data · Aug 14, 2026 · Not medical advice

Trial locations(7 sites)

United States

UCSF Medical Center-Mission Bay/Benioff Children's Hospital, San Francisco, California

Emory University Winship Cancer Institute, Atlanta, Georgia

Northwestern University, Chicago, Illinois

Massachusetts General Hospital Cancer Center, Boston, Massachusetts

Weill Cornell Medicine, New York, New York