4. Eliquis

BMS and Pfizer have pushed back Eliquis generic competition until at least 2026. (Pfizer & BMS)

Bristol Myers Squibb & Pfizer
2020 sales: $9.2 billion 
Key patent expirations: 2027 to 2029

Generic versions of Bristol Myers Squibb and Pfizer’s blockbuster Eliquis have already scored tentative FDA nods. But thanks to settlements and a key lawsuit last year, the pair have been able to fend off those cheaper rivals until at least 2026. 

Since first approved nearly a decade ago, the clot-fighter has become a star for Pfizer and BMS, which jointly develop and commercialize the drug that BMS discovered. Eliquis reaped $9.17 billion in sales last year, a 16% increase compared with 2019, earning a spot among 2020's top five best-selling drugs globally. The companies split profits and losses equally. 

RELATED: Bristol Myers Squibb's blood thinner Eliquis soars on COVID-19 demand, but Opdivo could suffer: execs

But for years, the duo has been hard at work fighting back generic rivals. In 2017, for instance, BMS and Pfizer erected a wall of patent infringement lawsuits against 25 companies that had filed for FDA approval of their generics. 

In August of that year, the U.S. Patent and Trademark Office granted Eliquis a key composition of matter patent, extending it from February 2023 to November 2026. The anticoagulant drug has another formulation patent that doesn’t expire until 2031. 

The pair ended up reaching legal settlements with several of those competitors, including Mylan—now Viatris—and Micro Labs, which scored tentative FDA clearance for the first two copycats in late 2019. However, not all of their rivals backed down.

RELATED: First generics to Bristol-Myers and Pfizer's Eliquis are here. But can they launch before 2026?

Then in August, the duo scored another major win when a Delaware district court judge upheld Eliquis’ patents against remaining challenges from Sigmapharm, Sunshine Lake and Unichem. That win, barring any results from an appeal or future challenges, secured Eliquis’ lock on the market for several years. 

It was a noteworthy gain for BMS, which is facing three of the decade's largest patent cliffs with Eliquis and cancer meds Revlimid and Opdivo. The impending generic attack has sent the New York pharma on an M&A feeding frenzy with its $74 billion Celgene acquisition and $13.1 billion MyoKardia buy.

Even still, the company has “significant financial flexibility” to pull off more deals, CEO Giovanni Caforio, M.D., said during the annual J.P. Morgan healthcare conference earlier this year. 

Pfizer is no stranger to looming generic foes, either. The company is expected to face its own patent cliff come 2026 for a handful of its strongest revenue drivers, including Eliquis, prostate cancer treatment Xtandi and top-selling blockbuster Prevnar 13. 

For Pfizer, Eliquis raked in $4.9 billion in 2020, an 18% bump compared with the prior year. In all, analysts have predicted that Pfizer will lose up to $20 billion in sales due to patent expirations starting in 2026.

For now, it's unclear when Eliquis generics might start to trickle in. For its part, BMS has said it expects generic entry after 2026 but before 2031. Analysts see reason to believe generics wouldn’t come into play until 2027 because of the possibility of a pediatric extension under FDA rules, which would add six months of market exclusivity. 

4. Eliquis