The end of the Humira era
With $219bn in accumulated sales the Abbvie mega-blockbuster is biopharma’s best-selling drug. Can Keytruda do better?
Humira's 20-year exclusivity period comes to an end this week, as the first biosimilar version hits the US market. The anti-TNF antibody has generated more than $200bn in global sales since launch, and analysts reckon it will be a blockbuster for a few years yet, thanks to Abbvie’s powerful grip on the US market.
Might other drugs rival this record? One possibility is Keytruda, which boasts huge sales forecasts, indicating that the Merck & Co checkpoint inhibitor could eventually amass similar lifetime sales. Look further out, and what could be an even bigger product lurks on the horizon.
That drug is Mounjaro, Lilly’s dual GLP/GIP agonist, approved in type 2 diabetes and gearing up for a hotly awaited move into obesity. Since it has only just been launched some analysts are still forecasting conservatively – Evaluate Pharma’s 2028 consensus currently sits at $11bn – but there are considerably higher numbers out there.
In 2032 Mounjaro could become biopharma’s first $100bn-a-year drug, Bank of America analysts wrote recently. Their projection assumes “modest penetration” across seven indications, including Nash and heart failure, as well as diabetes and obesity. It also implies a considerably larger lifetime sales potential than the products in the charts below.
Mounjaro has a lot to do before it earns a place in this analysis, however. Keytruda also has considerably more sales ahead of it than behind it, assuming analysts are correct; much depends on expansion into earlier, perioperative settings, as well as a successful switch to a subcutaneous formulation, which could help extend market exclusivity beyond 2028.
The same is true for Bristol’s checkpoint inhibitor rival Opdivo and its blood thinner Eliquis; Bristol is under pressure to bring the sales home on these two drugs before they face lower-cost competition.
Biologicals dominate the second chart here, which only considers sales already booked. The successful erection of so-called “patent thickets” around these complex molecules aided their longevity; with regulators and physicians growing more comfortable with biosimilars, such lifespans might not be possible in future.
Many believe that developers have been able to enjoy these exclusivity periods for far too long. The Inflation Reduction Act, which allows Medicare to negotiate its drugs bill for the first time and puts a cap on price hikes, can be read as a response to such excess.
But while the IRA might limit future lifespans, Humira is unlikely to feel much immediate pressure. Its first copycat is not expected to have particularly sharp claws: as the sole biosimilar available until mid-year Amgen's Amjevita might not be much cheaper, and access to it depends on the deals that have been struck with payers. Incentives for physicians to switch to biosimilars are not likely to kick in until at least 2024, SVB analysts wrote recently; Amgen itself has said it has "modest expectations" for Amjevita.
As a result, Humira is projected to retain its blockbuster status until the end of the decade, and possibly beyond. In fact all of the products below, except Epogen, will still be blockbusters in 2023, a status half of them are projected to retain out to 2028.
