2. Revlimid

Multiple myeloma
2015 sales: $5.8 billion
2020 projection: $10.2 billion

Celgene ($CELG) may have lain its foundation on Thalomid, the rehabilitated form of thalidomide redirected at cancer rather than morning sickness. But it was Revlimid that made the Summit, NJ-based drug developer into the Big Biotech it is today. And though Celgene has branched out beyond its multiple myeloma specialty--into breast, lung and pancreatic cancer with Abraxane, leukemia with Vidaza and anti-inflammatory disorders with Otezla--it still relies on Revlimid to power its top and bottom lines.

Approved to treat multiple myeloma, Revlimid brought in $5.8 billion in 2015, a 16% increase year over year. Celgene expects it to grow another 15% this year, to $6.6 billion to $6.7 billion. That's more than 60% of the company's expected sales for the full year, which Celgene forecast at $10.5 billion to $11 billion.

Of course, with patent expirations coming and biosimilars on their way, Revlimid can't shoulder that load forever. In late 2015, Celgene struck a patent settlement with India's Natco Pharma allowing a biosimilar to launch beginning in 2022, albeit in a limited way. Under the deal, Natco will be able to launch subject to volume limits that grow year by year until 2025. When 2026 dawns, the Indian drugmaker will be able to roll out its biosimilar Revlimid unfettered.

But that's years away. Revlimid is expected to keep going strong till 2020 at least, even as Celgene's follow-up drug Pomalyst takes hold in the market. The next-gen multiple myeloma treatment almost broke the blockbuster barrier in 2015, recording $983 million. That's a good thing for the company and the lofty sales goals set out by Chairman Bob Hugin. The company has targeted $12 billion by 2017, and if sales continue to grow at a 15% clip, Celgene would hit the bullseye. -- Tracy Staton (email | Twitter)

For more:
Celgene boosts Q4 sales by 24% on stalwart Revlimid, up-and-coming Otezla
Celgene opens door for early launch of Revlimid generics
FDA grants Celgene's Revlimid new use as it moves toward $10B in sales
New Celgene meds power forward, but Revlimid's still the Big Kahuna
Celgene's powerhouse Revlimid gets a little Q3 help from new friends Pomalyst, Otezla

2. Revlimid