Mavacamten (CAMZYOS) is a small-molecule modulator of cardiac myosin, mainly used for the treatment of adult patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM). 

Mavacamten (CAMZYOS):Clinical Uses, Recommended Dosage, Treatment Effect

Currently, mavacamten has been marketed in China. This article provides a detailed explanation of mavacamten's indications, usage and dosage, side effects, contraindications, clinical efficacy, etc.

(1) Indications

Mavacamten is indicated for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (obstructive HCM).

(2) Recommended Dosage

The recommended starting dose of mavacamten is 5 mg, taken orally once daily, regardless of food; subsequent allowed doses are 2.5 mg, 5 mg, 10 mg, or 15 mg orally once daily; the maximum recommended dose is 15 mg, taken orally once daily.

(3) Target Population

Adults. Pregnant and lactating women, children, and elderly patients should use the medicine under the guidance of a doctor.

(4) Contraindications

Moderate to strong CYP2C19 inhibitors or strong CYP3A4 inhibitors.

Moderate to strong CYP2C19 inducers or moderate to strong CYP3A4 inducers.

(5) Side Effects

Adverse reactions more common with mavacamten than with placebo (incidence > 5%) include dizziness and syncope.

(6) Precautions

Heart failure, heart failure or loss of efficacy due to CYP450 drug interactions, Mavacamten REMS Program, embryo-fetal toxicity.

(7) Drug Interactions

Possibility of other drugs affecting the blood concentration of mavacamten

Mavacamten is mainly metabolized by CYP2C19, followed by CYP3A4 and CYP2C9. Inducers and inhibitors of CYP2C19, as well as moderate to strong inhibitors or inducers of CYP3A4, may affect the exposure of mavacamten.

Possibility of mavacamten affecting the blood concentration of other drugs

Mavacamten is an inducer of CYP3A4, CYP2C9, and CYP2C19. Co-administration with substrates of CYP3A4, CYP2C19, or CYP2C9 may reduce the plasma concentrations of these drugs. Closely monitor when mavacamten is used in combination with substrates of CYP3A4, CYP2C19, or CYP2C9, as the reduction in plasma concentrations of these drugs may decrease their activity.

Drugs that reduce cardiac contractility

Mavacamten is expected to have an additive negative inotropic effect with other drugs that reduce cardiac contractility. Concomitant use of mavacamten in patients taking dipyridamole, ranolazine, verapamil combined with beta-blockers, or diltiazem combined with beta-blockers should be avoided, as these drugs and combinations increase the risk of left ventricular systolic dysfunction and heart failure symptoms, and there is limited clinical experience.

If concurrent treatment with negative inotropes is initiated, or the dose of negative inotropes is increased, closely monitor LVEF until a stable dose and clinical response are achieved.

(8) Storage Conditions

Store at 20°C to 25°C (68°F to 77°F), with allowable excursions between 15°C and 30°C (59°F and 86°F).