Once upon a time, reporters could definitively track down what drug patents would expire in a given year. Like lemmings, the medicines ran straight off the proverbial patent cliff. Generic manufacturers swooped in en masse and the inventor would lose up to 90 percent of its market share. Today, drug patent expirations are complex and blurred. “I see a lot of articles talking about, ‘this patent for this biologic expires in 2020,'” said Janet Xiao, co-chair of the Global Life Sciences Group at Morrison Foerster. “That may not be the complete story.”There are many ways to achieve a longer patent life, said Xiao in a phone interview, including through the use of second generation patents. The new IP could cover anything from manufacturing processes to a new drug formulation. It has been happening for a while, but the situation is set to escalate with the industry’s awkward transition into generic biologic drugs. If you’re looking for a less costly Viagra, you might want to ask your doctor about sildenafil. It's the active ingredient in both branded Viagra and the drug Revatio, which is a lower dose than Viagra and approved to treat pulmonary arterial hypertension. The important difference: Generic Revatio is available for a fraction of the cost. "Generic Revatio is considerably less expensive, and it is the same drug as Viagra with the same safety and effectiveness," says Bradley Anawalt, M. D., an endocrinologist and professor of medicine at the University of Washington in Seattle who chairs the Endocrine Society's Hormone Health Network. At a lower dose, sildenafil is approved to treat pulmonary arterial hypertension—the higher dose is reserved for treating erectile dysfunction (ED). Anawalt explains that there's a chance your insurance might not cover it to treat ED.
For Pfizer, its Viagra patent expiration was moved to whichever was longer; 17 years from the issue date Oct. 2019 or 20 years from the first. Pfizer's patent protection expires April 2020, but Teva will be allowed. copycat version of its popular erectile dysfunction drug Viagra in 2017.