Etcamah

Etcamah is used to treat hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer in adults in combination with a CDK4/6 inhibitor (abemaciclib, palbociclib, or ribociclib) that:

• has worsened or spread to other parts of the body (advanced or metastatic breast cancer), and
• has an estrogen receptor-1 (ESR1) mutation detected during treatment with an aromatase inhibitor and a CDK4/6 inhibitor.

Etcamah is a tablet taken once daily. Etcamah is for people who have already had at least 6 months of treatment with an aromatase inhibitor and a CDK4/6 inhibitor. Your healthcare provider will use an FDA-authorized test on a blood (plasma) sample to look for an ESR1 mutation. The test is repeated every 3 months until an ESR1 mutation is found.

Etcamah (camizestrant) is a potent, next-generation, oral selective estrogen receptor degrader (SERD) and complete ER antagonist that works by binding to the estrogen receptor alpha (ERα) and blocking it completely, with no partial stimulating (agonist) effect. It also flags the receptor for breakdown by the cell, reducing the amount of ERα available to drive tumor growth. It works against both normal (wild-type) and mutated ESR1 forms of the receptor. It belongs to the drug class called estrogen receptor antagonists.

Etcamah (camizestrant) received FDA approval on September 4, 2026, under the accelerated approval designation. The approval was based on progression-free survival, measured from the time the ESR1 mutation was detected. Continued approval for this use may depend on confirmation of a clinical benefit in further trials.

• The SERENA-6 Phase 3 clinical trial (NCT04964934) reported that adding Etcamah to a CDK4/6 inhibitor cut the risk of progression or death by 56% versus an aromatase inhibitor combination, extending median progression-free survival from 9.2 months to 16.0 months.

Etcamah carries a Boxed Warning for arrhythmia risk with concomitant use of QTc interval-prolonging drugs.

Arrhythmia risk with concomitant use of QTc interval-prolonging drugs

• Taking Etcamah in combination with ribociclib, which is a QTc interval prolonging drug and a strong CYP3A inhibitor, or in combination with other QTc interval prolonging drugs, can increase the risk of Torsades de Pointes, other ventricular arrhythmias, and sudden death.
• Avoid taking Etcamah with products other than ribociclib that are known to prolong the QTc interval or that have a known risk of Torsades de Pointes. If these products cannot be avoided, your healthcare provider will monitor your QTc interval more frequently.
• Your healthcare provider will do an electrocardiogram (ECG) before you start Etcamah, then every week for the first 2 weeks of treatment, and periodically during treatment as needed. They will check the levels of your body salts (electrolytes) and correct any abnormal levels before you start and during treatment.
• Your healthcare provider will withhold Etcamah until QTc interval prolongation resolves, then either restart it or stop it permanently, depending on how severe the problem was.

Other serious side effects

Etcamah can cause other serious side effects, including:

• Slow heart rate (bradycardia). Your healthcare provider will check your heart rate frequently during the first 30 days of treatment with Etcamah if you have bradycardia (heart rate less than 60 beats per minute) before starting treatment and if you take medicines that lower your heart rate.

Get medical help right away if you get the following signs or symptoms of QTc interval prolongation and bradycardia, including:

• dizziness
• lightheadedness
• fainting
• feeling that your heart is pounding or racing (palpitations)
• shortness of breath
• chest pain

Your healthcare provider may delay treatment or completely stop treatment with Etcamah if you have severe side effects.

Common side effects

The most common side effects of Etcamah in combination with a CDK4/6 inhibitor include:

• decreased white blood cell counts
• decreased red blood cell counts
• decreased platelet counts
• vision problems such as seeing flashes of light, double or blurry vision, light sensitivity, new or increased floaters. Tell your healthcare provider if you have vision problems, you may need to see an eye care specialist
• tiredness

Etcamah may cause fertility problems in females and males, which may affect your ability to have children. Talk to your healthcare provider if you have concerns about fertility.

These are not all the possible side effects of Etcamah. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

• Take Etcamah exactly as your healthcare provider tells you.
• Do not change your dose or stop taking Etcamah without talking to your healthcare provider.
• Take Etcamah 1 time a day, at about the same time each day.
• Take Etcamah with or without food.
• Swallow Etcamah whole. Do not cut, crush, or chew tablets before swallowing.
• Do not take Etcamah tablets that are broken, cracked or look damaged.
• Follow your healthcare providers' instructions for taking abemaciclib, palbociclib, or ribociclib (CDK4/6 inhibitors).
• If you miss a dose of Etcamah, take it within 6 hours from the time you usually take it. If it is more than 6 hours from the time you usually take your dose, skip the dose for the day. The next day, take the dose at your usual time. Do not take two doses to make up a missed dose.
• If you vomit after taking a dose of Etcamah, do not take another dose. Take your next dose of Etcamah at your usual time.

Before you take Etcamah, tell your healthcare provider if you:

• have any liver-related problems.
• have a slow heartbeat (bradycardia).
• have heart problems, including irregular heartbeats and QTc prolongation.
• are pregnant or plan to become pregnant. Etcamah can harm your unborn baby. Females who can become pregnant Your healthcare provider will check that you are not pregnant before you start treatment with Etcamah. Use effective non-hormonal birth control (contraception) during treatment with Etcamah and for 1 month after the last dose. Talk to your healthcare provider about birth control methods that may be right for you during this time. Tell your healthcare provider if you become pregnant or think you may be pregnant. Males with female partners who can become pregnant Use effective birth control during treatment with Etcamah and for 1 week after your last dose.
• are breast-feeding or plan to breastfeed. It is not known if Etcamah passes into your breast milk. Do not breastfeed during treatment with Etcamah and for 1 week after the last dose. Talk to your healthcare provider about the best way to feed your baby during treatment with Etcamah.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Especially, tell your healthcare provider if you take any heart and blood pressure medicines.

It is not known if Etcamah is safe and effective in children.

Recommended dosage

• The recommended dosage of Etcamah is 75 mg taken by mouth once daily, with or without food, until your disease progresses or you can no longer tolerate treatment.
• Take Etcamah at about the same time each day.
• Swallow the tablets whole. Do not cut, crush, or chew them, and do not take tablets that are broken, cracked, or not intact.
• Etcamah is taken in combination with a CDK4/6 inhibitor (abemaciclib, palbociclib, or ribociclib). The CDK4/6 inhibitor is continued at the same dosage you were taking when the ESR1 mutation was detected.

Dosage forms and strengths

Etcamah is supplied as 75 mg beige, round, bi-convex, film-coated tablets debossed with "CM" above "75" on one side and plain on the other side.

Missed or vomited dose

• If you miss a dose, take it within 6 hours of the time you usually take it. If it is more than 6 hours since your usual time, skip the dose for that day and take your next dose at the usual time the following day. Do not take two doses to make up for a missed dose.
• If you vomit after taking a dose, do not take another dose. Take your next dose at your usual time.

Dose changes for side effects

No dose reductions of Etcamah are recommended. If you have side effects, your healthcare provider may withhold Etcamah until the side effect improves and then restart it, or may stop it permanently, depending on how severe the side effect is.

Dosage if you have liver problems

• If you have severe liver impairment (Child-Pugh C) and are taking Etcamah with ribociclib, the recommended dosage is 75 mg once every other day.
• If you have severe liver impairment (Child-Pugh C) and are taking Etcamah with abemaciclib or palbociclib, no change to your Etcamah dosage is needed.
• If you have moderate (Child-Pugh B) or severe (Child-Pugh C) liver impairment and are taking Etcamah with any CDK4/6 inhibitor, your healthcare provider will monitor you more closely for side effects and may change your dosage.

Etcamah may affect the way other medicines work, and other medicines may affect how Etcamah works.

• Strong CYP3A inhibitors: Watch for increased side effects and adjust the Etcamah dose as recommended. Examples include the antifungals itraconazole and ketoconazole, the antibiotic clarithromycin, and ritonavir. Ribociclib, one of the CDK4/6 inhibitors given with Etcamah, is also a strong CYP3A inhibitor.
• Strong or moderate CYP3A inducers: Avoid taking with Etcamah. If a moderate inducer cannot be avoided, the Etcamah dose needs adjusting when it is given with abemaciclib or palbociclib. Examples include rifampin, the anticonvulsants carbamazepine and phenytoin, and the herbal supplement St John's wort.
• CYP2C9 or CYP2C19 substrates: Avoid during Etcamah treatment and for at least 2 weeks after the last dose, unless that medicine's prescribing information advises otherwise. Examples include warfarin, phenytoin, omeprazole, and clopidogrel.
• CYP3A substrates: Check the substrate's prescribing information, because small rises in its blood levels may cause serious side effects. Examples include some statins, such as simvastatin, and the immunosuppressants ciclosporin and tacrolimus.

Know the medicines you take. Keep a list of them to show your healthcare provider or pharmacist when you get a new medicine.

• Store Etcamah at room temperature between 68°F to 77°F (20°C to 25°C).
• Store Etcamah in the original bottle.
• The bottle contains a desiccant to keep tablets dry. Do not remove the desiccant from the bottle.
• Keep the bottle tightly closed to protect from moisture.
• Throw Etcamah away after 30 days if it has been stored in a bottle without a desiccant.

Keep Etcamah and all medicines out of the reach of children.

Active ingredient: camizestrant

Inactive ingredients: anhydrous dibasic calcium phosphate, magnesium stearate, microcrystalline cellulose, and sodium starch glycolate.

The tablet film-coating contains ferric oxide red, ferric oxide yellow, ferrosoferric oxide, polyethylene glycol 3350, polyvinyl alcohol, talc, and titanium dioxide.

Etcamah is distributed by AstraZeneca Pharmaceuticals LP, Wilmington, DE 19850.