This morning, Sanofi (NYSE:SNY) and Regeneron (NASDAQ:REGN) released some good news from a phase 3 study of its experimental cholesterol drug alirocumab, a new treatment designed to lower the production of LDL ("bad") cholesterol.
A new approach at lowering LDL cholesterol levels
Alirocumab attempts to lower LDL cholesterol by stopping the PCSK9 enzyme from binding to LDL receptors, which are essential in removing LDL cholesterol from the blood. PCSK9 degrades these LDL receptors, limiting the liver's ability to lower LDL cholesterol levels.
The previous generation of cholesterol-lowering treatments -- such as Pfizer's (NYSE:PFE) Lipitor, AstraZeneca's (NYSE:AZN) Crestor, and Merck's (NYSE:MRK) Zocor -- are all statins. Statins inhibit the production of LDL cholesterol by targeting an enzyme known as HMG-CoA in the liver. However, statin treatments have been shown to actually stimulate the production of PCSK9, which is counterproductive, possibly damaging to the liver, and ultimately limits the treatment's ability to lower LDL cholesterol levels.
Positive phase 3 results
In Sanofi and Regeneron's phase 3 trial, alirocumab was shown to reduce LDL cholesterol three times more than ezetimibe (marketed as Zetia or Ezetrol), a non-statin treatment that decreases the absorption of cholesterol in the small intestine. The results -- in which patients on alirocumab exhibited a 47.2% reduction in LDL compared to 15.6% for ezetimibe -- exceeded the phase 3 trial's primary endpoints.
During the 24-week study, patients initially self-injected the drug at a low dose of 75 mg every two weeks, but it was increased to a double dosage if LDL levels did not drop by the eighth week. However, the majority of patients were able to remain on the lowest dose since their LDL levels fell by the eighth week.
Although these results indicate that alirocumab could be on the right path to approval, the drug, like ezetimibe, caused some unpleasant side effects such as the common cold, influenza, and respiratory infections.
More detailed results from the study will be presented in 2014.
The road ahead
Besides alirocumab, which is a monoclonal antibody, Sanofi and Regeneron are also developing "fully human" monoclonal antibodies developed by Regeneron's VelocImmune technologies. These "fully human" monoclonal antibodies could eventually replace the current use of "humanized" monoclonal antibodies, which are altered from animal anitbodies.
However, those treatments, along with alirocumab, are still a long ways off.
For now, Sanofi's key growth driver is its diabetes franchise, which reported 12.9% year-over-year growth last quarter, although it faces generic competition for many of its other key products, such as Eloxatin, Plavix, Avapro, and Lovenox.
Most of Regeneron's revenue is currently generated by Eylea, a treatment for wet age-related macular degeneration that's co-marketed with Bayer. Sales of Eylea rose 50.7% year-over-year last quarter, although it faces competition from Novartis' Lucentis and Roche's Avastin.
Should investors be excited?
During pre-market trading at the time of this writing, investors appeared fairly indifferent to Sanofi and Regeneron's phase 3 announcement. At 9 a.m EST, shares of Sanofi were basically flat at $49.39, while shares of Regeneron were up 4.4% at $303.20.
Investors interested in other "next generation" LDL treatments might also want to check out Alnylam Pharmaceuticals, which is using gene silencing technology to lower cholesterol levels without the side effects of statin treatments.
Leo Sun has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.