Pfizer's legendary Viagra finally set to face cheaper competition in U.S.

Under a 2013 settlement with Teva, Pfizer will face generic competition to Viagra on Monday.

All these years after its initial approval, Pfizer's little blue pill Viagra is coming to the end of its patent life. Still, the company has plans to keep its key med churning. 

The drugmaker on Monday will launch its own generic at half the price of branded Viagra, according to the Associated Press. The move comes as Teva Pharmaceutical Industries gets the green light to compete with the legendary brand nearly 20 years after Viagra's initial FDA nod in 1998. 

Back in 2013, Pfizer inked a settlement with Teva that allows the generics giant to launch a Viagra copycat on Dec. 11. Other knockoffs will flood the market after a 180-day waiting period—set to expire next June—further driving prices down for the erectile dysfunction drug. 

To defend against the new competition, Pfizer plans to launch a discounted white pill, plus bolster its discounts and copay assistance, according to the AP; the company is also selling direct to patients for those who are uninsured. On the Viagra website, Pfizer is already offering 50% off copay or out-of-pocket expenses for a yearlong supply. 

It's been quite a run for Viagra during its nearly two decades' worth of patent protection. The company's hold nearly ran out in 2011, but then it had a later patent legally confirmed. Teva appealed and the companies settled on a December 2017 generic launch date. Under the settlement, Teva has to pay royalties until 2020. 

Over the years, Pfizer has turned its drug into a household name through aggressive DTC advertising, and recently the company has worked to continue its sales momentum with a single-pack and a text-for-coupon campaign. 

Viagra is among the top meds in FiercePharma's list of the biggest patent losses in 2017, topped only by rival Cialis from Eli Lilly and Teva's multiple sclerosis med Copaxone. Since the report, though, Eli Lilly entered an agreement with multiple generics makers that will extend Cialis' exclusivity on the market. 

Viagra brought in $1.6 billion globally and $1.16 billion in the U.S. last year. In data compiled earlier this year, market intelligence firm Evaluate predicted that Viagra would fall to $359 million in U.S. sales next year and $188 million by 2022. The firm predicts $1.1 billion in U.S. sales for 2017. 

As pharma sometimes does as key meds near the end of their patent life, Pfizer has raised the prices on Viagra significantly this year, according to a June report from Financial Times. The company increased prices twice for the med in 2017—in January and June—totaling a 27.5% increase.

Viagra is already competing against generics elsewhere in the world. In the U.K., where copies were introduced four years ago, Pfizer has introduced an over-the-counter version.