FDA Grants Accelerated Approval to AstraZeneca's Etcamah
The FDA has granted accelerated approval to AstraZeneca's Etcamah for HR-positive, HER2-negative advanced breast cancer with ESR1 mutations, based on a
The U.S. Food and Drug Administration has granted accelerated approval to a new breast cancer treatment from AstraZeneca. The drug, Etcamah (camizestrant), is approved for use with a CDK4/6 inhibitor for adult patients with hormone receptor-positive, HER2-negative, locally advanced or metastatic breast cancer who have developed a specific resistance mutation.
This approval targets tumors that have acquired an estrogen receptor-1 (ESR1) mutation during prior treatment with an aromatase inhibitor and a CDK 4/6 inhibitor. At initial diagnosis of metastatic disease, fewer than 5 percent of patients have this mutation. After the disease progresses on an aromatase inhibitor, that figure rises to nearly 40 percent.
"Women living with metastatic breast cancer face an uphill battle as their tumors continuously evolve to escape treatment," said Acting FDA Commissioner Kyle Diamantas, J.D. "Today’s approval delivers a win to these patients by granting them a targeted therapy designed specifically to overcome resistance."
Basis for Accelerated Approval
The accelerated approval is based on how long patients lived without their disease worsening, a measure known as progression-free survival. The FDA noted this approval is not yet confirmed to translate into a clinically meaningful benefit, so the agency has required confirmatory studies. The decision marks a first for the agency.
"This marks the first FDA approval of a cancer therapy guided by the detection of a resistance mutation in circulating tumor DNA (ctDNA) before imaging tests show that the disease is progressing," said Angelo de Claro, M.D., director of the FDA’s Oncology Center of Excellence. "But additional evidence is needed to confirm clinical benefit."
Circulating tumor DNA consists of tiny pieces of tumor DNA released into the blood, allowing for earlier molecular detection of resistance. To identify eligible patients, the FDA also authorized the Guardant360 CDx assay as a companion diagnostic.
Clinical Trial Results
Efficacy was evaluated in a clinical trial comparing a switch to oral Etcamah plus a CDK4/6 inhibitor against continuing an aromatase inhibitor plus a CDK4/6 inhibitor. The trial measured progression-free survival from the point the ESR1 mutation was first detected in the blood.
The results showed a significant improvement in the time patients lived without their cancer advancing.
| Treatment Arm | Estimated Median Progression-Free Survival |
|---|---|
| Etcamah + CDK4/6 inhibitor | 16 months |
| Aromatase inhibitor + CDK4/6 inhibitor | 9.2 months |
Safety Information and Next Steps
The prescribing information for Etcamah includes a boxed warning for the risk of irregular heart rhythm when taken with certain other medications. It also carries warnings for an abnormally slow heart rate and potential harm to an unborn baby. Full prescribing information will be posted on the FDA's Drugs@FDA website.
The FDA's Oncologic Drugs Advisory Committee reviewed the application for this drug on April 30, 2026. The accelerated approval program allows for earlier approval of drugs for serious conditions that fill an unmet medical need, using surrogate endpoints like progression-free survival. AstraZeneca must now complete studies to verify the drug's clinical benefit.
Acting Commissioner Diamantas stated the approval reflects the FDA's commitment to advancing medical innovation and getting new treatments to patients who need them.
