Triple-Negative Breast Cancer (TNBC) Clinical Trials

About Triple-Negative Breast Cancer (TNBC) trials

TNBC is defined by the absence of three markers (ER, PR, and HER2), so trials use the markers that vary among TNBC patients to determine eligibility. BRCA1 and BRCA2 status is critical because germline BRCA mutations occur in 15-20% of TNBC patients and define eligibility for PARP inhibitor trials. PD-L1 status (usually measured by combined positive score) gates several immunotherapy trials. PIK3CA mutations are tested but less actionable in TNBC than in HR-positive disease, though that's changing as new combinations emerge. Your oncologist orders these from your tumor sample. If your biopsy is older, ask whether it's still acceptable or whether a re-biopsy is needed.

Trials open right now split cleanly between early-stage and metastatic disease. Early-stage TNBC trials are dominated by neoadjuvant immunotherapy combinations, with the IO + chemo backbone now standard for high-risk early disease. Trials in this space test new IO combinations and adjuvant strategies for patients with residual disease after surgery. Metastatic first-line trials test IO combinations in PD-L1 high disease and chemo + ADC combinations more broadly. Metastatic later-line trials are heavily ADC-focused right now, with several molecules competing across lines. PARP inhibitor trials are active for BRCA-mutated patients, both in earlier settings (post-neoadjuvant) and metastatic. Phase 1 trials in TNBC tend to test novel targets and combinations earlier than other subtypes because the unmet need is high.

TNBC trials typically build their eligibility around stage, prior treatment, and a few clinical checkpoints. Stage and treatment intent: early-stage trials require specific clinical or pathologic stage; metastatic trials care about prior line count. For metastatic trials: prior immunotherapy is a defining criterion (most trials are IO-naïve, IO-pretreated, or post-IO progression specific), as is prior ADC exposure (which agent and which line increasingly matters). For PARP trials: confirmed germline or somatic BRCA1 or BRCA2 mutation. PD-L1 status is required for many IO trials. Brain metastasis status and whether they're treated. ECOG of 0 or 1 is standard.

Biomarkers tested in Triple-Negative Breast Cancer (TNBC) trials

These are the molecular markers most commonly required or evaluated in Triple-Negative Breast Cancer (TNBC) eligibility criteria. OncoMatch extracts them from each trial's protocol and matches them against your test results.