US FDA extends PDUFA date and seeks additional data from AstraZeneca’s NDA for camizestrant in combo with a CDK 4/6 inhibitor to treat HR-positive, HER2-negative advanced ...

The US Food and Drug Administration (FDA) has extended the Prescription Drug User Fee Act (PDUFA) review date for AstraZeneca’s New Drug Application (NDA) for camizestrant in combination with a cyclin-dependent kinase (CDK) 4/6 inhibitor (palbociclib, ribociclib, or abemaciclib). The treatment targets hormone receptor (HR)-positive, HER2-negative advanced breast cancer patients whose tumors develop an ESR1 mutation, based on the SERENA-6 phase III trial results presented at ASCO 2025 and published in *The New England Journal of Medicine*. The FDA granted Breakthrough Therapy Designation for this combination in May 2025, but its Oncologic Drugs Advisory Committee did not reach a majority vote in April 2026 for approval after detecting ESR1 mutations in circulating tumor DNA (ctDNA). AstraZeneca has since submitted additional analyses, including ctDNA clearance data linked to long-term efficacy, which will be presented at ASCO 2026 on June 2. The European Medicines Agency’s Committee for Medicinal Products for Human Use recommended approval of the camizestrant combination in May 2026, while the drug is already approved in the United Arab Emirates and Saudi Arabia. Regulatory reviews are ongoing in Japan and other countries based on SERENA-6 trial results. Breast cancer is the second most common cancer globally, with over 2 million diagnoses in 2022 and more than 665,000 deaths. In the US, it is the most common cancer in women, with over 300,000 new cases annually. HR-positive, HER2-negative breast cancer accounts for 70% of cases, often treated with endocrine therapies paired with CDK4/6 inhibitors, though resistance develops in many patients, limiting survival rates to about 36% beyond five years post-diagnosis for metastatic cases.