US FDA approves AstraZeneca's new breast cancer pill Etcamah: Dosage, high risk and side effects — Everything you need to know

The U.S. Food and Drug Administration (FDA) said on Friday it granted fast-track approval to AstraZeneca Plc’s breast cancer pill, which expands treatment options for adult patients with advanced breast cancer.

The drug, known as camizestrant, can be used in combination with other cancer drugs in patients who have a genetically determined form of metastatic breast cancer.

AstraZeneca has launched camizestrant, which will be branded ETCAMAH®.

Etcamah is an anticancer medicine used to treat adults with breast cancer that is locally advanced (spread nearby) or metastatic (spread to other parts of the body); it is used in combination with a drug belonging to the class of CDK4/6 inhibitors (palbociclib, ribociclib or abemaciclib).

ETCAMAH is also approved in more than 30 countries worldwide, including the EU, Japan, Canada, the UK and several other countries based on the SERENA-6 Phase III study.

Benefits and risks

Etcamah works like a hormone therapy by stopping estrogen from stimulating cancer cells, which helps prevent these cells from growing. The drug maker has shown that the pill can help delay the progression of the disease by more than six months.

Patients with this drug are breast cancer patients who have a specific mutation that can develop during endocrine therapy treatment. Patients will have to undergo an FDA-approved test to prove they have this mutation before being given Etcamah.

“The approval (was) based on the results of the SERENA-6 phase III trial, which showed that the combination reduced the risk of disease progression or death by 56% in patients with an emerging ESR1 tumor mutation,” AstraZeneca said.

Dosage: ETCAMAH is a potent oral selective estrogen receptor degrader (SERD) and complete new-generation ER antagonist, administered orally once daily.

The recommended dose of ETCAMAH in combination with a CDK4/6 inhibitor is 75 mg, AstraZeneca said.

Etcamah is only available on prescription and treatment should be initiated and monitored by a physician experienced in the use of anticancer drugs.

“Etcamah is available as tablets to be taken by mouth once a day. Treatment should be continued for as long as the patient benefits from it or until unacceptable side effects occur,” says the European Medicines Agency.

High risk: The drug poses a high risk to pregnant women. “Based on animal findings and mechanism of action, ETCAMAH may cause fetal harm when administered to a pregnant woman. Advise pregnant women and women of the reproductive potential of the potential risk to the fetus,” the company said.

It also advised women not to breastfeed during treatment with ETCAMAH and for one week after the last dose.

Side effects: According to the European Medicines Agency, the most common side effects of Etcamah in combination with a CDK4/6 inhibitor (which may affect more than 1 in 10 people) include neutropenia (low levels of neutrophils, a type of white blood cell), visual effects (including photopsia, seeing flashes of light in the field of vision), infections, diarrhoea, red blood cells, nausea and weakness bradycardia (slow heart rate) and leukopenia (low white blood cells).

These side effects specifically associated with Etcamah included visual effects and bradycardia. Some side effects can be serious. The most common (which may affect up to 1 in 10 people) include infection and fever.

What else do we know about the Etcamah breast cancer pill?

The approval was based on the results of the pivotal phase III SERENA-6 study presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting and published simultaneously in The New England Journal of Medicine.

Earlier this year, the FDA’s Oncology Drugs Advisory Committee voted against the drug, finding it lacked “meaningful benefit” for patients. But in Friday’s approval, the agency said the drug would give women with breast cancer another way to treat the disease.

Kevin Kalinsky, MD, MS, FASCO, director of the Division of Medical Oncology, Winship Cancer Institute of Emory University and an investigator for the study, said, “The combination provides an important new option for the one in three patients with this form of advanced breast cancer whose tumors develop ESR1 mutations before clinical or radiographic disease progression.”

“Today’s approval will allow physicians to quickly intervene and change therapeutic strategy at an earlier opportunity before disease progression, rather than waiting until the cancer becomes more difficult to treat and patient outcomes and quality of life deteriorate,” Kalinsky said.

Breast cancer is the most common cancer among women in the U.S., with more than 300,000 new cases diagnosed and more than 42,000 deaths annually, the FDA said, citing WHO data.

Under the leadership of CEO Pascal Soriot, AstraZeneca has launched a number of successful cancer drugs. The company is looking to secure continued growth from a number of oncology drugs while positioning itself to compete in the red-hot market for medical weight loss treatments.