Last year, Merck's Keytruda became the world's top selling drug for the first time. Here's a look at the 15 largest pharmaceuticals by worldwide revenue, how their sales changed from 2022, and some notable trends.

For many years, AbbVie's Humira held the crown as the world's top selling drug, peaking at ~$21B in 2022.

While Humira has faced biosimilar competition in Europe for years, things shifted dramatically in 2023, when Amgen's biosimilar Amjevita launched and became the first of several challengers in the US market. As a result, Humira sales declined by almost a third in 2023 to $14.4 billion. Even so, AbbVie's years of work to strengthen its pipeline have meant the company has performed well, with overall revenues declining by less than 10% compared to FY 2022.

Obesity & GLP-1s: While Ozempic made the list, those prescribed specifically for weight loss, Wegovy and Zepbound (from Lilly), did not - but expect to see them soon, as they've ramped their sales at an incredible pace.

To illustrate - Lilly's Mounjaro, which like Novo's Ozempic is indicated for diabetes, achieved $5.1B in sales in 2023, despite achieving only $500M in 2022, an unprecedented speed of uptake post launch.

The list also highlights other strong performers:

Sales of Sanofi's Dupixent rose more than 30% from 2022 and crossed $11B in sales last year, while Merck's HPV vaccine Gardasil approached $9B in sales. AbbVie's autoimmune drug Skyrizi also notched impressive sales gains of almost 50%.

But several face looming competition:

Eylea will see patent expirations in EU5 markets and Japan in 2025, while J&J's Stelara will see expirations in Europe in 2024, and likely face US competition in 2025.
Meanwhile, BMS faces twin challenges from Opdivo and Eliquis, which have key patent expirations from 2026-2028. That has driven active dealmaking by BMS, with over $20B in M&A in the last 6 months alone.

The upcoming LOEs highlight a persistent challenge for the biopharma industry, which has grown increasingly acute in the last few years as companies race to strengthen their pipelines ahead of significant expected sales declines.

A tougher biotech funding market following the boom years of 2020/2021 has meant that companies which do receive funding and advance to later stage trials are often strong and possess differentiated assets. Yet that often means that large biopharma companies are often competing over a limited pool of best-in-class or first-in-class assets, which drives up valuations.