Generics Bulletin Explains: One Year On, US Humira Biosimilars Continue To Struggle For Share

This time last year, all eyes were on the US biosimilars market, as the off-patent industry’s biggest ever single loss-of-exclusivity opportunity in history loomed.

Humira (adalimumab) had already faced biosimilar competition in Europe – with four rivals launching simultaneously back in 2018 (Also see "Four adalimumabs compete in EU" - Generics Bulletin, 26 Oct, 2018.) – but even that moment paled in comparison to the prospect of almost ten biosimilars hitting the US market in 2023, all of them aiming to capture a slice of the top-selling brand’s once-$17bn market. (Also see "Humira In 2023: The $17bn Biosimilar Opportunity" - Generics Bulletin, 5 Jan, 2023.)

However, in the year since Amgen launched the first US Humira biosimilar – in the form of its Amjevita (adalimumab-atto) version at the end of January – followed by a second wave of several Humira rivals that launched simultaneously at the start of July (see sidebar), the many biosimilar competitors on adalimumab seem to have struggled to achieve a significant foothold.

Analysts and industry leaders had always predicted that there would be a somewhat gradual ramp-up for Humira rivals in their first year of availability, with the January and July launch dates for biosimilars not aligning cleanly with contracting cycles that would already be in place for Humira going into 2023.

But even taking this into account, recent figures from the end of 2023 shared by Samsung Bioepis in its quarterly biosimilars report were fairly lacklustre, with the report slamming the “stagnant biosimilar uptake” that saw adalimumab biosimilars altogether capturing just 2.0% of the market as the year ended.

Even the most successful individual biosimilars – Organon and Samsung Bioepis’ Hadlima, along with Amjevita, according to the report – had respectively captured just 0.8% and 0.7% of the adalimumab market. (Also see "Samsung Bioepis Biosimilars Report Slams ‘Stagnant’ US Adalimumab Uptake" - Generics Bulletin, 18 Jan, 2024.)

This slow uptake for adalimumab biosimilars is not for want of competition on price. Humira’s various rivals are offering a wide range of pricing options, with some approaching a 90% discount compared to the brand.

Many suppliers are also offering multiple pricing options, following on from the example set by Amgen when it launched Amjevita at two different price points to “address the complexity of the US market” – namely, pharmacy benefit managers preferring higher list prices with substantial rebates over low list prices. (Also see "Amgen Talks Dual Pricing Strategy For Amjevita" - Generics Bulletin, 1 Feb, 2023.)

However, “despite the introduction of adalimumab biosimilars priced at significant discounts, a major savings opportunity remains unrealized,” the report highlighted.

A Wide Variety Of Options Available – But Little Uptake

Similarly, there seems to be no deficit in the variety of presentations of biosimilar adalimumab being offered. Multiple alternatives are available, including both high-concentration 100mg/ml and low-concentration 50mg/ml offerings, in various different unit sizes.

Meanwhile, two of the biosimilars on offer have also been deemed interchangeable with Humira, with more interchangeable versions likely on the way soon. (Also see "FDA Decision On Interchangeable Exclusivity Allows Pfizer To Rival Boehringer On Adalimumab" - Generics Bulletin, 9 Oct, 2023.)

That said, according to the Samsung Bioepis report, interchangeability “has not yet been demonstrated as a distinguishing factor,” with Cyltezo (adalimumab-adbm) – Boehringer Ingelheim’s first interchangeable biosimilar that has been on the market since July – enjoying just 2% of the already small share of the market that is occupied by biosimilars. However, the report concedes, “this may change with approval of high-concentration interchangeable products on the horizon.” (Also see "Alvotech Lines Up US Biosimilar Approvals After FDA Inspection" - Generics Bulletin, 22 Jan, 2024.)

Indeed, all indications are that the US biosimilar Humira market is still at an early stage in its development in general, and much could still change.

“Most major PBMs have announced parity access to one or more adalimumab biosimilars, initiating a first step in access for these products,” Samsung Bioepis acknowledged in its report. (Also see "Another PBM Favors Sandoz And Boehringer On Adalimumab" - Generics Bulletin, 11 Jul, 2023.)

However, this is tempered by the fact that PBMs have so far been selective about which biosimilars would be included on formularies, often only selecting two or at most three biosimilars for inclusion.

The report concludes that “slow adoption to date may suggest that prescribers and specialty pharmacies have not yet determined the best practices to navigate payer biosimilar preferences and may favor the originator to avoid treatment delays.”

Similarly, adoption in Medicare has started slow, with most plans continuing to cover most or all Humira products and many Part D plans not covering any of the available biosimilars. (Also see "Humira Biosimilar Adoption Starts Slow In Medicare" - Generics Bulletin, 23 Jan, 2024.)

Some Suppliers Had Predicted A Slow Ramp-Up

The relatively muted success of adalimumab biosimilars so far was not entirely unexpected. While anticipation of competition to Humira was high, some suppliers had gone out of their way to keep expectations in check.

One such company was Organon. At the start of this year, CEO Kevin Ali recalled comments made a year ago in which he was cautious about how quickly the adalimumab market would take off. (Also see "Organon Foresees US Adalimumab Discounts Hitting 80%-90%" - Generics Bulletin, 11 Jan, 2023.)

“I was sitting here a year ago, and I was actually the person who was kind of signaling that it’s going to be a slower uptake, that people should be ready for that,” the CEO recollected at the start of 2024 (see sidebar). “I think a lot of people were very bullish, and I was more kind of being conservative.”

“2024 is still a year of market formation,” Ali suggested, predicting that the market would in 2024 “see sequentially more penetration quarter-by-quarter, definitely.” It was “just going to be a slower build.”

And some signs of significant change are already being seen this year, with CVS recently announcing a move to eliminate branded Humira from major national formularies from the start of Q2, in favor of biosimilars – albeit coupled with a simultaneous deal to partner with AbbVie on co-branded Humira. (Also see "Adalimumab Uptake Set For A Boost As CVS Drops Humira From Formularies" - Generics Bulletin, 9 Jan, 2024.)

Erosion Has Gone ‘Exceptionally Well’ For AbbVie

And what of the originator’s take on how competition to Humira has played out? For AbbVie, it seems like a combination of its pricing and contracting strategies with the sluggishness of the market to switch to biosimilars have created a highly favorable environment for the brand to continue to thrive.

At the start of this year, AbbVie management commented that erosion had gone “exceptionally well” for the company, adding that recent developments on contracting for 2024 meant that Humira was “going to have more parity access than we initially anticipated.”

Acknowledging that this would “step down year-over-year,” AbbVie nevertheless said it was currently enjoying “a very good position” for Humira, expecting “the majority of the erosion in 2024 to really come from price” (see sidebar).

Having already increased its rebates to buyers midway through 2023 – to “make sure that we maintain parity access, make sure that our patients have that continuity of access” – AbbVie had offered further “additional rebates for 2024 to maintain that level of parity access,” company management disclosed.

This meant erosion would be “predominantly price” in 2024, although “there will be some volume.”

“Although it is too early to determine the fate of the US adalimumab market,” the Samsung Bioepis biosimilars report concludes, current market realities “delay biosimilars from playing a pivotal role in alleviating the financial burden the US healthcare system and patients currently face.”

And the impact of muted uptake for adalimumab biosimilars could stretch beyond just one product. Already, it appears that the way AbbVie has managed competition to Humira may be being viewed as the model for another major biologic target on the horizon, in the form of Stelara (ustekinumab).

Stelara is expected to face US biosimilar competition from early 2025 under a series of settlements between originator J&J and biosimilar developers, not dissimilar to the framework of settlements that allowed Humira biosimilars to enter the market in 2023. (Also see "History Repeating: Will US Stelara Settlements Follow Humira’s Lead?" - Generics Bulletin, 13 Jun, 2023.)

Given the scale of the opportunity – Stelara now represents a $10bn global target, with almost $7bn of sales coming from the US alone (Also see "A $10bn Target: Stelara Sales Break Barrier Ahead Of Biosimilar Launches" - Generics Bulletin, 26 Jan, 2024.) – it could be essential for biosimilars developers to learn lessons from experiences with Humira if they hope to more quickly make inroads into the next major immunology LOE on the horizon.