Rare heart condition gets new treatment option

Condition overview:
Obstructive hypertrophic cardiomyopathy (oHCM) is a genetic, progressive disease in which the heart muscle thickens, mostly in the wall between the right and left sides. This makes it harder for the heart to pump blood to the rest of the body.

Drug name:            Camzyos™ (mavacamten)
Manufacturer:        Brystol Myers Squibb
Condition:               obstructive hypertrophic cardiomyopathy (oHCM)

HCM is estimated to affect one in every 500 people, however many patients remain undiagnosed and/or asymptomatic.¹  About two-thirds of HCM cases are obstructive, and about half of oHCM patients get symptoms like chest pain, shortness of breath, swelling in the legs and decreased capacity for exercise. Symptoms can also include atrial fibrillation, heart failure, and malignant ventricular arrhythmias.

Current treatment:
First-line pharmacotherapy focuses on symptom relief with beta-blockers and non-dihydropyridine calcium channel blockers. However, side effects such as fatigue and dizziness can result in inadequate efficacy for these treatments.

Second-line pharmacotherapy includes disopyramide. This may also may have an insufficient treatment effect; data supporting its use is relatively weak. There are contraindications and multiple side effects associated with its use. However, it is still considered an important treatment option.

There are surgical options to improve blood flow. Septal reduction procedures, including surgical myectomy or alcohol septal obstruction, may have a substantial benefit in patients with drug-refractory symptoms, but also have a low risk of death.

Camzyos (mavacamten) overview:^2-6
Camzyos (mavacamten) is an oral modulator of cardiac myosin.  In oHCM, cardiac myosin impacts heart muscle contractility, its ability to pump blood.  BMS anticipates mavacamten may be added onto first line therapies before moving onto second line pharmacotherapy.

 Effectiveness
The effectiveness and safety of Camzyos to treat NYHA class II-III oHCM was studied in adults who were randomly assigned to receive Camzyos or a placebo for 30 weeks. At the end of the study, 37% of participants treated with Camzyos improved on an endpoint measuring exercise capacity and symptoms, compared to 17% of participants in the placebo group.²

A change of at least 5% is considered clinically important. These gains returned to baseline after treatment was stopped.

Institute for Clinical and Economic Review (ICER):⁶
A review of the EXPLORER-HCM data led ICER to rate mavacamten in addition to first-line therapy as ‘promising but inconclusive’ compared to first-line therapy alone. They assigned the same rating to the evidence of mavacamten compared with disopyramide. ICER did not assign an evidence rating to the comparison of mavacamten versus septal reduction therapies. The cost-effectiveness analysis estimated the health benefit price benchmark for mavacamten to be $12,000-$15,000. The annual wholesale acquisition cost is $89,500.

Camzyos received breakthrough therapy designation and orphan drug designation for this indication.

Date approved:     March 29, 2022
Benefit:                   Pharmacy benefit, oral

Prime monitors the drug pipeline
The drug pipeline is full of new, groundbreaking specialty drugs that may help members live better and feel well. Prime focuses on clinical strategies designed to keep clients ahead of drug trends — because it’s easier to manage change when you see it coming.

---

References

1. Mavacamten Is Effective in Treating Obstructive Hypertrophic Cardiomyopathy. May 15, 2021. DAIC news. Copyright Wainscot Media. https://www.dicardiology.com/content/mavacamten-effective-treating-obstructive-hypertrophic-cardiomyopathy
2. FDA approves new drug to improve heart function in adults with rare heart condition. FDA.gov. April 29, 2022. https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-new-drug-improve-heart-function-adults-rare-heart-condition
3. com U.S. FDA accepts Bristol Myers Squibb’s application for mavacamten in symptomatic obstructive hypertrophic cardiomyopathy (oHCM). Accessed November 2021: https://news.bms.com/news/details/2021/U.S.-Food-and-Drug-Administration-FDA-Accepts-Bristol-Myers-Squibbs-Application-for-Mavacamten-in-Symptomatic-Obstructive-Hypertrophic-Cardiomyopathy-oHCM/default.aspx
4. Olivotto I, Oreziak A, Barriales-Villa R, et al. Mavacamten for treatment of symptomatic obstructive hypertrophic cardiomyopathy (EXPLORER-HCM): a randomized, double-blind, placebo-controlled, phase 3 trial. Lancet 2020; 396: 759-69.
5. Data on file. BMS. September 2021.
6. org Mavacamten for hypertrophic cardiomyopathy: effectiveness and value. Final evidence report: November 16, 2021. Accessed in November 2021 at: https://icer.org/wp-content/uploads/2021/04/ICER_HCM_Final_Evidence_Report_111621.pdf
7. FDA approves Bristol Myers’ oral heart disease drug | Reuters