Humira's Denouement: The Biosimilar "Cliff" That Became a Slope

In a classic blockbuster story, the ending is loud. Patents expire, competition arrives, the old champion falls off a cliff.

Humira didn’t end like that.

The better word is denouement—not the climax, but the unwinding after it. If you expected January 2023 to be a clean rupture, what followed looked more like a slow fade shaped by contracts, change management, and the quiet persistence of brand.

Humira was the reference product everyone watched because it wasn’t just big—it was structural. At its peak, Humira moved over $20 billion annually—a central line item in every specialty spend conversation.

So when biosimilars finally arrived, many people expected a rapid conversion story: lower-cost alternatives enter, utilization flips, and the market moves on.

But immunology blockbusters don’t behave like commodity generics. And Humira’s denouement shows why.

One detail captures the whole dynamic: the first Humira biosimilar (Amjevita) was FDA-approved back in September 2016, yet didn’t launch in the U.S. until January 2023.

That seven-year gap foretold the transition was never going to be instantaneous.

When the U.S. launch window finally opened, the early market data still looked surprisingly calm. IQVIA noted that despite numerous adalimumab biosimilars entering, their combined share remained around ~1% at the end of 2023.

Then came a real operational inflection: CVS Caremark announced it would remove Humira from major national commercial template formularies effective April 1, 2024, while still allowing Humira access through opt-out formulary options for some clients.

And by 2025, the story shifted again: multiple analyses of the Big Three PBMs’ standard formularies described a move toward PBM-preferred (often private-label) biosimilars and broader exclusions of competing marketed biosimilars.

There are a few practical forces that can make a biosimilar transition feel slower than expected—even when lower list prices exist.

Contracting and “template vs. reality”

Even when a large PBM makes a template formulary change, real coverage is messier. Clients may opt out, customize, or phase changes to manage disruption. “We’ll wait til 1/1” is a decision that can delay implementation 6–9 months.

Switching friction is real

Autoimmune patients who are stable on therapy create a different conversion dynamic than a patient picking up a new generic antibiotic. The “best price” decision still must travel through prescribers, patient comfort, prior authorization workflows, and the operational weight of change.

The market arrived with complexity, not simplicity

Adalimumab biosimilars aren’t one clean substitute. They come with variations (concentration, citrate-free status, interchangeability, device familiarity). Even when clinical equivalence is not the question, workflow equivalence still matters.

Brand inertia is a legitimate force

One of the under-discussed lessons: brand isn’t just marketing—it’s operational trust accumulated over years. IQVIA’s reporting on new starts illustrates that even after biosimilars entered, Humira remained the dominant choice for many new initiations through 2024.

It’s simply what the market looked like when a once-in-a-generation product finally began to sunset.

The most interesting late-stage development wasn’t merely “biosimilars win.” It was who got to define which biosimilars won.

By 2025, multiple reports described how large PBMs favored private-label or PBM-affiliated biosimilar options (Quallent / Cordavis / Nuvaila), often alongside tighter exclusion lists for competing versions. More closed, more exclusive deals lead to better rates on singular products and portfolios as well.

Whether you view that as good, bad, or neutral, it’s a signal: the biosimilar era may be shaped as much by channel and portfolio strategy as by the existence of competition.

Humira’s denouement is useful because it sets expectations for the next wave of biologic transitions—Stelara has been messy too:

If you’re an employer or plan sponsor watching the next blockbuster unwind, Humira leaves you with a few governance-grade questions:

Humira didn’t end with a bang. It ended with an unwinding—and that unwinding is probably the true reflection of future biosimilar avalanches to come.