These tablets are a generic therapeutic equivalent to Gilead‘s Letairis (ambrisentan; marketed by GlaxoSmithKline under the brand name Volibris in the European Union), a medication approved by the FDA for treating patients with pulmonary arterial hypertension (PAH) (specifically patients in the World Health organization (WHO) Group 1).
ANDA is a type of classification for generic medications seeking FDA approval. Once approved, the company that submitted the application earns the rights to manufacture and market the therapy as an equally safe, effective, and lower cost alternative to the brand-name product (in this case, Letairis).
Of note, generic drug applications are termed “abbreviated” because usually they do not require preclinical (animal) or clinical (human) data to establish their safety and effectiveness. Instead, researchers must show that the generic therapy performs in the same manner as the approved, referenced product.
Ambrisentan is an endothelin receptor antagonist, that works by competing with endothelin for binding to the endothelin type A-receptor. Endothelin is a small peptide that works as a vasoconstrictor. That is, it is able to trigger blood vessels’ contractions once it binds to its receptor.
When endothelin is active, blood vessels contract and become smaller; subsequently the blood pressure increases. However, in the presence of ambrisentan, the amount of endothelin that is able to bind to type A-receptors decreases, reducing blood vessels’ contractions, and lowering blood pressure.
Because of its ability to lower blood pressure in the arteries of the lungs, and improve the distribution of oxygenated blood throughout the body, ambrisentan is recommended to improve exercise capabilities and slow disease progression in PAH patients.
According to a Cipla press release, statistics indicate that in 2018 sales of Letairis tablets reached $943 million in the U.S. alone. The company says its ambrisentan generic tablets are now available for shipping.
Cipla is the third largest pharmaceutical company in India, and one of the biggest distributors of generic medications in the U.S. Ambrisentan is part of the company’s initiative to promote therapies’ inclusiveness, accessibility, and affordability.