The Bottom Line
- Market Exclusivity Confirmed: Novartis’s patent and supplementary protection certificate (SPC) for its key cardiovascular drug, a combination of valsartan and sacubitril (marketed as Entresto®), have been upheld in the Netherlands. This secures its market exclusivity until the SPC expires in 2028.
- Setback for Generics: Generic drug manufacturer Synthon is blocked from launching its version of the drug in the Dutch market. The ruling underscores the significant hurdles generics face in invalidating patents for complex combination therapies.
- High Bar for “Obviousness”: The decision reinforces a crucial legal principle: for a patent to be invalid for being “obvious,” challengers must prove more than a mere “hope to succeed.” A clear “reasonable expectation of success” based on prior scientific knowledge is required.
The Details
The dispute centered on the validity of Novartis’s European patent for its highly successful drug, which combines valsartan (an angiotensin II receptor blocker, or ARB) and sacubitril (a neprilysin, or NEP, inhibitor). Generic manufacturer Synthon sought to invalidate the patent, arguing that the invention lacked an “inventive step.” Synthon contended that, based on the scientific landscape in 2002 (the patent’s priority date), it would have been obvious for a pharmaceutical research team to combine these two classes of drugs to treat hypertension and heart failure.
The Hague Court of Appeal firmly rejected this argument, siding with Novartis and the lower court. A key element of Synthon’s case was the assertion of a “class effect”—the idea that prior art suggested any ARB could be successfully combined with any NEP inhibitor. The Court meticulously analyzed the scientific literature from the period and found no such clear signal. Instead, it noted that the evidence was complex and often inconsistent. Different ARBs were known to have distinct pharmacological properties, and early studies on similar combinations had produced mixed or even discouraging results, meaning a skilled person could not simply assume all drugs in these classes were interchangeable.
Ultimately, the Court determined that while a researcher could have experimented with this specific combination, there was no “reasonable expectation of success.” The scientific knowledge at the time pointed toward numerous potential research pathways, including more established combinations like ARBs with diuretics. Without a clear “pointer” in the prior art singling out the valsartan/sacubitril combination as uniquely promising, the path to the invention was not considered obvious. The Court drew a sharp distinction between a mere “hope to succeed” in a research project and the higher legal standard required to render a patent invalid, concluding that Novartis’s invention was indeed inventive.
Source
The Hague Court of Appeal
