
The biggest-selling drugs of 2023
Move over Comirnaty: Keytruda takes top spot as its indications broaden and demand for Covid vaccines recedes.

Pfizer might be set to become the biggest-selling pharma company of 2023, but Merck & Co’s Keytruda should easily take the crown for this year’s most successful product. According to Evaluate Vantage’s 2023 Preview, the PD-1 inhibitor is expected to outsell its nearest rival by almost $4bn.
Keytruda owes its success to Merck’s fruitful expansion strategy, which has seen the checkpoint inhibitor chalk up approvals in 38 settings. The cancer drug is also forecast to be 2023’s biggest grower, with strong demand seen adding $3bn in new sales over the next 12 months.
Declining demand for Covid vaccines, following western government policies of ‘living with Covid’, have seen the two main pandemic vaccines slip down the best-selling rankings. Comirnaty is expected to cede the top spot to Keytruda, while Moderna’s Spikevax is set to drop five places, becoming the ninth biggest-selling drug this year.
However, the forecasts for 2023’s top-selling drugs were completed before China’s decision to end its ‘zero-Covid’ policy. Although the Chinese government has so far refused the offer of external vaccines, surrounding countries are seeing increased demand for mRNA jabs. The opening up of China could spark more Covid cases globally, driving need for both vaccines and treatments like Pfizer's Paxlovid.
End of the road
What is notable about 2023’s biggest sellers is the number of products approaching their twilight-years. Humira, the drug that dominated the top of the charts between 2012 and 2022, is set to lose patent protection in the US this month.
There are currently nine authorised generics waiting to launch, making it difficult to estimate the pace of sales erosion of Abbvie’s all-time great. Price could be a key differentiator among the competitors, potentially hastening Humira’s sales decline.
Johnson & Johnson's psoriasis product Stelara is also due to succumb to competition in the US this year. But J&J can take comfort in the multiple myeloma drug Darzalex, a valuable source of new sales and the forecast fourth biggest-selling drug in 2028.
Finding new sales will be high on the agenda for Bristol Myers Squib, which is facing a steep patent cliff from 2026 onwards as its top 10 products, the blood thinner Eliquis and PD-1 inhibitor Opdivo, start to lose exclusivity.
Future earners
As to what will replace the drugs at risk in future lists, there are clues in the list of products forecast to generate the most new sales in 2023.
Lilly’s Mounjaro is definitely one to watch. The diabetes drug, fast becoming beloved of celebrities using it for weight loss off label, was predicted to produce almost $2bn in sales over the year; some analysts have predicted turnover could hit $30bn in 2030. Since our 2023 Preview was written, consensus has moved even higher, with some banks expecting 2023 sales to approach $3bn.
Such has been the interest around the dual GLP-1/GIP agonist’s ability to induce weight loss there are concerns Lilly could struggle to keep up with demand.
Rising obesity and type 2 diabetes rates are also set to benefit Novo Nordisk’s Wegovy and Ozempic, which are forecast to generate combined new sales of $4bn in 2023.
Few products could compensate for the loss of Humira, but the new autoimmune drugs Skyrizi and Rinvoq will not only add $2.5bn in new sales, but move Abbvie up the biggest company rankings; Abbvie is expected to hit revenues of $64bn in 2028.
For these insights and more, download your free copy here: Evaluate Vantage 2023 Preview