Patent protection offers exclusivity to a drug maker/marketer to reap the profits monopolistically during the patent period. However, each patent has an expiration date after which the generic versions of the drug get introduced in the market and can erode the market share of the original product. (For more, see Patents, Trademarks and Copyrights: The Basics.)

Drug Patents Set to Expire in 2017

Here’s a list of top five medicines losing patent protection in 2017, as per an infographic provided by Dickson Data. The list is arranged in declining order of annual revenue estimates.

With annual estimated revenue of $1.6 billion revenue, the top rung is held by Novartis AG’s (NVS) Sandostatin LAR, a drug used to treat problems caused by certain types of tumors. Several generic versions of this drug from various drug makers like Teva Pharmaceuticals Industries Limited (TEVA), Sun Pharma Industries, and Fresenius Kabi are approved by the U.S. Food And Drug Administration (FDA) and will be hitting the market post patent expiry of Sandostatin LAR.

Merck & Co Inc.’s (MRK) Cubicin, an antibiotic drug which is used to fight off bacterial infection will lose its patent this year. The drug has $1.17 billion annual revenues, and will face competition from generics made by Crane Pharmaceuticals LLC, Pfizer Inc.’s (PFE) subsidiary company Hospira Inc., and Teva.

Bristol-Myers Squibb Co.’s (BMY) Reyataz (atazanavir), which is used in combination with other drugs as an anti-viral medication to prevent human immunodeficiency virus cells from multiplying in the human body, has $1.14 billion annual revenue. It will face competition from Teva Pharmaceuticals’ generic which got approved in 2014.

Merck’s Vytorin, which has $1.12 billion annual revenues, is a cholesterol drug soon to lose its patent. It is a combination of ezetimibe and simvastatin and works by reducing the amount of cholesterol absorbed by the body.

Eli Lilly & Co.’s (LLY) Strattera (atomoxetine), which has close to $700 million annual revenues and is used to treat attention deficit hyperactivity disorder (ADHD), is next in the list of drugs about to lose the patent exclusivity in 2017.

Beyond the top five, other prominent drugs in the list are Merck’s Invanz and Cancidas, Pfizer’s Relpax and Somavert, Questcor’s Acthar Gel, Teva’s Azilect, and Roche’s Tamiflu.

While Merck has the maximum number of four drug patents expiring in 2017, representing around $3.8 billion or 10% of its total annual revenue, GlaxoSmithKline PLC (GSK) has three, and Eli Lilly has two. (For more, see Patents Are Assets, So Learn How To Value Them.)