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Opsumit (MACITENTAN)

Opsumit works by blocking the action of endothelin-1, a protein that causes blood vessels to constrict and increase blood pressure.

Opsumit (Macitentan) is a small molecule endothelin receptor antagonist developed by Actelion, targeting the endothelin-1 receptor to treat pulmonary arterial hypertension. It was FDA approved in 2013 and has since become a widely available generic medication. As a generic medication, Opsumit is no longer patented, with multiple manufacturers producing the drug. Key safety considerations include monitoring for liver function and potential interactions with other medications. Opsumit has been shown to improve exercise capacity and slow disease progression in patients with pulmonary arterial hypertension.

At a glance

Mechanism of action

Endothelin (ET)-1 and its receptors (ETA and ETB) mediate variety of deleterious effects, such as vasoconstriction, fibrosis, proliferation, hypertrophy, and inflammation. In disease conditions such as PAH, the local ET system is upregulated and is involved in vascular hypertrophy and in organ damage.Macitentan is an endothelin receptor antagonist that inhibits the binding of ET-1 to both ETA and ETB receptors. Macitentan displays high affinity and sustained occupancy of the ET receptors in human pulmonary arterial smooth muscle cells. One of the metabolites of macitentan is also pharmacologically active at the ET receptors and is estimated to be about 20% as potent as the parent drug in vitro. The clinical impact of dual endothelin blockage is unknown.

Approved indications

• Pulmonary arterial hypertension

Boxed warnings

• WARNING: EMBRYO-FETAL TOXICITY OPSUMIT is contraindicated for use during pregnancy because it may cause fetal harm based on animal data [see Contraindications (4.1) , Warnings and Precautions (5.1) , Use in Specific Populations (8.1) ]. Therefore, for females of reproductive potential, exclude pregnancy before the start of treatment with OPSUMIT. Advise use of effective contraception before the initiation of treatment, during treatment, and for one month after stopping treatment with OPSUMIT [see Dosage and Administration (2.2) , Use in Specific Populations (8.3) ]. When pregnancy is detected, discontinue OPSUMIT as soon as possible [see Warnings and Precautions (5.1) ]. WARNING: EMBRYO-FETAL TOXICITY See full prescribing information for complete boxed warning. Based on animal data, OPSUMIT may cause fetal harm if used during pregnancy ( 4.1 , 5.1 , 8.1 ). Females of reproductive potential: exclude pregnancy before start of treatment. Prevent pregnancy prior to initiation of treatment, during treatment and for one month after treatment by using effective methods of contraception ( 2.2 , 8.3 ). When pregnancy is detected, discontinue OPSUMIT as soon as possible ( 5.1 ).

Common side effects

• anemia
• nasopharyngitis/pharyngitis
• bronchitis
• headache
• influenza
• urinary tract infection

Drug interactions

• rifampin
• ketoconazole
• ritonavir
• fluconazole
• amiodarone

Key clinical trials

• Outcome Study Assessing a 75 Milligrams (mg) Dose of Macitentan in Patients With Pulmonary Arterial Hypertension (PHASE3)
• A Study Providing Treatment Access in Participants With Pulmonary Hypertension Completing a Parent Study and Having no Other Option (PHASE3)
• A Study to Assess Whether Macitentan Delays Disease Progression in Children With Pulmonary Arterial Hypertension (PAH) (PHASE3)
• Efficacy and Mechanisms of Macitentan for Non-Coronary Obstructive Angina (EARLY_PHASE1)
• Clinical Study to Compare the Efficacy and Safety of Macitentan and Tadalafil Monotherapies With the Corresponding Fixed-dose Combination Therapy in Subjects With Pulmonary Arterial Hypertension (PAH) (PHASE3)
• A Study of Macitentan in Japanese Pediatric Participants With Pulmonary Arterial Hypertension (PHASE3)
• Effects of Combination Medical Therapy Followed by BPA on Right Ventricular-PA Coupling and Hemodynamics in CTEPH (PHASE3)
• Clinical Trial to Evaluate the Efficacy and Safety in Concomitant Administration of Macitentan and Dapagliflozin in Patients With Heart Failure With Mildly Reduced and Preserved Ejection Fraction (HFmrEF and HFpEF) and Combined Pre- and Post-capillary Pulmonary Hypertension (CpcPH) (PHASE4)

Patents

Primary sources

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