2. Keytruda

Merck & Co.'s Keytruda has followed its aggressive pipeline to blockbuster sales. (Merck & Co.)

Company: Merck & Co.
2019 sales: $11.12 billion
Projected 2026 sales: $24.91 billion
Projected CAGR: +12%
Used for: melanoma, non-small cell lung cancer, small cell lung cancer, head and neck cancer, Hodgkin lymphoma, large B-cell lymphoma, bladder cancer, colorectal cancer, stomach cancer, esophageal cancer, cervical cancer, liver cancer, Merkel cell carcinoma, kidney cancer (in combination with Inlyta), endometrial cancer (in combination with Lenvima)

Merck & Co.'s superstar immuno-oncology med Keytruda rode into megablockbuster territory on a wave of regulatory approvals, and with even more on the way, the drug is looking at an ever-brighter future in the sales department. 

Keytruda hit $11.12 billion in 2019 on the back of its bustling pipeline of new indications. With even more approvals already in the bag in 2020—and more likely on the way—Keytruda could be staring at an eye-popping $24.91 billion in sales in 2026, according to Evaluate Pharma. 

Keytruda's success starts and ends with its remarkably successful run in the clinic, and 2020 has already been a lucrative year for the PD-L1 inhibitor. 

RELATED: Merck's Keytruda lands new colorectal cancer nod, its 2nd biomarker-based OK this month

2. Keytruda