Efficacy and Safety Comparison of Niraparib to Placebo in Participants With Human Epidermal Growth Factor 2 Negative (HER2-) Breast Cancer Susceptibility Gene Mutation (BRCAmut) or Triple-Negative Breast Cancer (TNBC) With Molecular Disease

To join this study, your breast cancer must be one of two types: either triple-negative breast cancer (no matter your BRCA gene status) or HR-positive/HER2-negative breast cancer with a known faulty BRCA gene. You must have already had surgery to remove the main part of the cancer and finished any other standard treatments like chemotherapy or radiation. For HR-positive breast cancer, you should be on a stable dose of hormonal therapy.

An important requirement is that a special blood test must show small amounts of cancer DNA (called ctDNA) in your blood, even after your initial treatments. This tells the researchers you might be at higher risk of the cancer returning.

There are also some reasons you might not be able to join. For example, if you've already taken a similar type of drug called a PARP inhibitor, or if your cancer has spread to other parts of your body. Also, if your general health isn't good enough, or if you've had certain other cancers in the past, you might not be eligible. The study team will check all these details carefully.

The detailed information about what taking part involves isn’t fully explained in the summary provided. However, generally, in a clinical trial like this, you would expect to visit the clinic regularly for check-ups, blood tests, and scans. You would be given either the study drug (Niraparib) or a placebo (a dummy pill) to take, likely daily, for a set period. There would be regular health assessments to monitor how you're responding to the treatment and to check for any side effects. After the main treatment period, there would likely be follow-up appointments to track your long-term health. The total duration of participation, including treatment and follow-up, would be fully explained by the study team.