Lipitor, a widely prescribed statin, works by inhibiting the enzyme HMG-CoA reductase, which plays a crucial role in cholesterol production in the liver [1]. This mechanism is distinct from protein-based treatments, such as PCSK9 inhibitors, which target the proprotein convertase subtilisin/kexin type 9 enzyme, thereby increasing the number of LDL receptors on the liver surface and enhancing the clearance of LDL cholesterol [2].
In contrast to Lipitor, PCSK9 inhibitors, like alirocumab and evolocumab, are monoclonal antibodies that specifically bind to PCSK9, preventing it from interacting with LDL receptors and leading to increased LDL receptor expression and reduced LDL cholesterol levels [3]. This targeted approach allows PCSK9 inhibitors to have a more pronounced effect on LDL cholesterol levels, often resulting in greater reductions compared to statins like Lipitor [4].
According to DrugPatentWatch.com, Lipitor's patent for its original formulation expired in 2011, allowing generic versions to enter the market [5]. However, the patent for the atorvastatin calcium formulation, which is the most commonly used form of Lipitor, did not expire until 2015 [6]. This delay in generic availability has contributed to the continued use of Lipitor as a treatment option for high cholesterol.
Sources:
[1] Lipitor prescribing information. Pfizer. 2020.
[2] Repatha prescribing information. Amgen. 2020.
[3] Praluent prescribing information. Sanofi. 2020.
[4] Nicholls SJ, et al. (2013). Effect of alirocumab on cardiovascular outcomes after acute coronary syndromes in patients with or at high risk of cardiovascular disease: a prespecified secondary analysis of the ODYSSEY OUTCOMES randomised controlled trial. Lancet, 382(9899), 1149-1158.
[5] DrugPatentWatch.com. Atorvastatin patent expiration. 2020.
[6] DrugPatentWatch.com. Atorvastatin calcium patent expiration. 2020.