Mavacamten
CAMZYOS
Pronunciation: mav-a-KAM-ten
“Cam Zeus, Myosin actin’”
What it isCardiac myosin inhibitor reducing actin-myosin cross-bridging; obstructive hypertrophic cardiomyopathy in adults and children ≥30 kg.
Why this oneThe first oral therapy to target HCM hypercontractility directly, it can defer septal reduction.
What limits itSystolic dysfunction requires echocardiographic monitoring under a REMS. CYP2C19 variation changes exposure severalfold.
FDA-approved for
- obstructive hypertrophic cardiomyopathy (2022)
- obstructive HCM in children weighing at least 30 kg (2026)
Classes and tags
Clinical profile
Legacy pregnancy categoryNot assigned — PLLR-era drug
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Symptomatic obstructive HCM | Adult | 5 mg QD | individualized 2.5–15 mg QD | 15 mg QD |
| Obstructive HCM + moderate CYP2C19 or strong CYP3A4 inhibitor | Adult | 2.5 mg QD (one dose below recommended start) | individualized | 15 mg QD |
| Symptomatic obstructive HCM | Pediatric ≥45 kg | 5 mg QD | individualized 1–15 mg QD | 15 mg QD |
| Symptomatic obstructive HCM | Pediatric 30 kg to <45 kg | 2.5 mg QD | individualized 1–15 mg QD | 15 mg QD |
| Obstructive HCM + moderate CYP2C19 or strong CYP3A4 inhibitor | Pediatric ≥30 kg | one dose below weight-band starting dose | individualized | 15 mg QD |
Titration Assess LVEF and Valsalva LVOT gradient before each up-titration (weeks to steady state); when on an interacting inhibitor, do not up-titrate until 12 weeks after inhibitor initiation.
Renal No clinically significant PK difference in mild–moderate impairment (eGFR 30 to 89); severe (eGFR 15 to 30) and kidney failure unknown
Hepatic No adjustment for mild–moderate (Child-Pugh A/B) with the standard titration/monitoring plan; severe (Child-Pugh C) unknown.
Available only through the CAMZYOS REMS Program.
Instructions
- Swallow capsules whole; do not break, open, or chew.
- Take once daily with or without food.
- Confirm absence of pregnancy and use effective contraception before starting.
- If a dose is missed, take as soon as possible; do not take two doses the same day.
- Initiation or up-titration not recommended if LVEF <55%.
- Interrupt treatment if LVEF <50% or on worsening clinical status; delay dose increases during intercurrent illness or arrhythmia.
Available strengths
- cap 2.5, 5, 10, 15 mg
Contraindications
- Concomitant strong CYP2C19 inhibitors.
- Concomitant moderate-to-strong CYP2C19 inducers or moderate-to-strong CYP3A4 inducers.
Cautions
- Heart failure due to systolic dysfunction; higher risk with intercurrent illness or arrhythmia.
- CYP2C19/CYP3A4 drug interactions leading to heart failure or loss of effectiveness.
- Embryo-fetal toxicity; may reduce effectiveness of some hormonal contraceptives.
- Avoid with disopyramide, ranolazine, or verapamil/diltiazem plus a beta blocker.
Adverse reactions
- dizziness (27%)
- syncope (6%)
Pregnancy May cause fetal harm (animal data); confirm absence of pregnancy before starting and use contraception during and 4 months after last dose.
Lactation No data on presence in milk or effects on infant/production; weigh benefits.
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 2.5 mg | cap | 30 qd | not offered | |
| 5 mg | cap | 30 qd | not offered | |
| 10 mg | cap | 30 qd | not offered | |
| 15 mg | cap | 30 qd | not offered |
Generic entry2034 est.
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Memory aids: interaction avatars
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Self-check
- What monitoring is required because mavacamten can cause systolic dysfunction?
Echocardiographic monitoring under a REMS. - Which CYP variation can change mavacamten exposure severalfold?
CYP2C19.