Amgen v. Sanofi: Patent Battles, PCSK9 Inhibitors, and Drug Pricing Wars

When Amgen v. Sanofi, a major U.S. patent lawsuit over cholesterol-lowering biologic drugs went to court, it wasn’t just about who invented what—it was about whether a company could lock down a life-saving drug for decades using thin patents. The fight centered on PCSK9 inhibitors, a class of injectable drugs that dramatically lower LDL cholesterol, including Amgen’s Repatha and Sanofi’s Praluent. These drugs weren’t pills—they were complex biologics, harder to copy than traditional generics, and priced at over $14,000 a year. The outcome didn’t just affect two companies—it reshaped how the FDA and courts handle biologic patents, and it opened the door for cheaper versions to eventually reach patients.

The core issue? Amgen claimed Sanofi copied its antibody design, but Sanofi argued Amgen’s patents were too broad and didn’t actually describe how to make the drug. The Supreme Court sided with Sanofi in 2023, ruling that Amgen’s patent didn’t provide enough detail to let others replicate the invention. This decision sent shockwaves through the biotech industry. If a company can’t clearly describe how to make a biologic in its patent, it can’t stop others from making similar versions—even if they use slightly different methods. That’s a big win for biosimilars, lower-cost versions of complex biologic drugs. It means future drugs like those for rheumatoid arthritis, cancer, or multiple sclerosis could face competition sooner, driving prices down. For patients, this could mean thousands in savings. For insurers and Medicare, it could mean billions in reduced spending.

What you’ll find in the posts below isn’t just about this one lawsuit. It’s about the ripple effects: how patent battles delay generic access, why some drugs stay expensive even after patents expire, and how patients navigate high-cost meds when alternatives are scarce. You’ll see how drug pricing ties into everything—from insurance coverage to pillbox stability, from fiber interactions to antidepressant access. The same system that lets Amgen sue Sanofi also lets pharmacies repackage pills, lets doctors prescribe off-label, and lets patients miss doses because they can’t afford refills. This isn’t abstract legal drama. It’s your medication on the shelf, your co-pay at the counter, your next doctor’s visit. These posts connect the dots between courtroom decisions and real-life health choices.