FDA fast tracks BRCA breast cancer drug

The US Food and Drug Administration (FDA) has granted fast track status to a new drug combination for BRCA-mutated advanced breast cancer.

The designation covers ART6043, developed by Artios, used with the PARP inhibitor Lynparza, also known as olaparib.

It applies to adults with germline BRCA-mutated, HER2-negative locally advanced or metastatic breast cancer who have not previously been treated with a PARP inhibitor.

BRCA mutations are inherited genetic changes that increase the risk of breast cancer.

PARP inhibitors block cancer cells from repairing damaged DNA, but tumours with BRCA mutations often develop resistance when these drugs are used alone.

ART6043 is designed to address this resistance. The oral treatment inhibits DNA polymerase theta, or Polθ, an enzyme found in cancer cells but largely absent in healthy tissue.

By blocking Polθ, the drug targets a backup DNA repair process known as microhomology-mediated end joining, which cancer cells rely on when other repair pathways are disrupted.

The aim is to limit the tumour’s ability to repair itself and extend the effectiveness of PARP inhibitors.

The fast track decision was supported by data from an ongoing first-in-human phase 1/2a trial evaluating ART6043 in combination with Lynparza in patients with advanced solid tumours carrying mutations in DNA damage response pathways, including BRCA-mutated breast cancer.

Findings presented at the European Society for Medical Oncology Congress 2025 showed what the company described as expected pharmacokinetic and pharmacodynamic activity, as well as encouraging clinical signals.

Breast cancer is the second leading cause of cancer death among women in the US. Patients with BRCA mutations who develop resistance to PARP inhibitors often have limited treatment options.

The FDA fast track programme is intended to speed up the development and review of investigational medicines that may address serious or life-threatening conditions with unmet medical need.

The designation allows Artios to engage more frequently and earlier with the FDA to discuss the development pathway for ART6043.

Under the programme, the drug candidate may be eligible for priority review and accelerated approval if it meets the relevant clinical criteria.

HER2-negative breast cancer does not overproduce the HER2 protein, which drives tumour growth in some patients.

Locally advanced cancer has spread to nearby tissue but not distant parts of the body, while metastatic cancer has spread to other organs.