Ten biosimilar versions of Humira (adalimumab) have launched since 2023 but have achieved very little traction thus far, largely due to the competitive pricing and rebate dynamics of U.S. managed markets. In August 2023, Caremark announced the launch of Cordavis which would co-promote and commercialize Hyrimoz with Sandoz as well as AbbVie’s Humira. This partnership came to bear in April 2024 when Caremark added Hyrimoz and “removed” Humira from major template formularies.

Early reports showed Hyrimoz share rapidly increased after Caremark’s announced formulary change, particularly within new prescriptions, instigating many conversations around the changing tide among pharmacy biosimilars in the U.S.  Though these events are still recent, much can be learned from the early months of the evolving adalimumab landscape.

A new business model

The common strategy of rebating for access leaves little room for biosimilars to compete when innovators have the leverage of scale and are willing to negotiate steep discounts. This scenario leads some biosimilar manufacturers to opt for a two-price approach wherein one version of their biosimilar launched with higher prices and steep rebates along with another, unbranded version launched at a much lower price point that was comparable to net. Nevertheless, there has been little incentive for payers and patients to switch volume from the innovator to its biosimilars, thus enabling Humira to retain at least 97% of total adalimumab volume through March 2024.

Share of Adalimumab Claims Trend, All Payer Channels

Note: April 2024 marks a one-time bolus of patients switching from Humira to initiate treatment with Hyrimoz which subsides over time
Source: IQVIA LAAD Pharmacy Claims, US Market Access Strategy Consulting analysis

Yet, a new business model could subvert common practices. The partnership between biosimilar manufacturer Sandoz and Caremark venture Cordavis creates an alternative path for biosimilars to offer value and disrupt the usual incentives that favor innovators. By co-promoting the biosimilar Hyrimoz through Cordavis, Caremark is able to ensure a steady supply for its specialty pharmacy and likely share in the sales. As such, Hyrimoz accounted for 14% of all U.S. adalimumab claims in April 2024 and 16% in June 2024 (up from 1% the month before the venture launched). These trends were observed across commercial and Part D payer channels but not Medicaid.

Shortly after the Cordavis co-promotion of Hyrimoz launched, a Cordavis version of Humira also entered the market. By June 2024, 5% of all adalimumab claims and 11% of all new patients were using the Cordavis version of Humira. Express Scripts’ co-promotion with Teva’s unbranded biosimilar and Humira through distributor Quallent also launched in June 2024, promising savings and $0 out-of-pocket costs through its specialty pharmacy, Accredo. With two large pharmacy benefit managers pursuing co-promotion, the paradigm of parity access between Humira  select biosimilars may be short-lived.

Muted innovator attrition

The recent success of Hyrimoz does not quite foretell the end of Humira, partly because the strategy has not been more widely adopted and partly because Humira’s own co-promotion with Cordavis (and now Quallent) delays loss of volume to a competitor. In 2024 so far, 23% of patients that switched from Humira to another adalimumab filled the co-promoted Humira and 60% filled co-promoted Hyrimoz.

Co-promotions facilitated patient switching in a way that was previously unobserved for adalimumab biosimilars despite interchangeability and parity access. Stable patients (which make up more than 90% of the adalimumab market) tend to remain with their current therapy and are largely unaffected by new formulary exclusions. With a co-promotion, however, PBMs have the option to move continuing patients to a discounted biosimilar or co-promoted version of the innovator. As the number of adalimumab patients switching from the innovator to a biosimilar or co-promotion increases, Humira retains volume that could otherwise have been lost to a biosimilar.

Distribution of Humira Switches to Biosimilar, All Payer Channels

Note: Patients that move from Humira to co-promoted Humira are counted as a switch in this analysis
Source: MAAS Pharmacy Biosimilar Library, US Market Access Strategy Consulting analysis

Before Caremark launched Cordavis, nearly all patient starts on an adalimumab biosimilar were naïve to treatment as opposed to switching from Humira. Still, biosimilars only made up a small proportion of new starts. In 2023, only 2% of treatment naïve patients initiated adalimumab therapy with a biosimilar. In 2024 to date, that number increased to 14%, including biosimilars and the Humira co-promotion. Nevertheless, Humira continues to make up 86% of new adalimumab patients in 2024 to date.

Within a given biosimilar’s new patient starts, most have switched from the innovator Humira. Though not all Humira patients are switching to a biosimilar or co-promotion, very few new biosimilar patients are treatment naïve or switched from another biosimilar. Hyrimoz and its unbranded adalimumab-adaz have some of the highest proportions of naïve patients apart from Humira, which is exclusively made up of adalimumab-naïve patients. Though switching patterns could evolve as Quallent implements its own co-promotions.

New adalimumab Patients by Source of Business, All Channels, Jan 2023-Jun 2024

Note: Patients that move from Humira to co-promoted Humira are counted as a switch in this analysis
Source: MAAS Pharmacy Biosimilar Library, US Market Access Strategy Consulting analysis

Rewriting the playbook

At the time of Humira’s loss of exclusivity, it was unclear what role interchangeability and concentration could have on biosimilar access and uptake. Formularies continued to cover the innovator, and some biosimilars launched multiple versions, offering both low list prices and discounted high prices.

A co-promotion, made possible by PBMs’ vertical integration of specialty pharmacies and benefit management, sidesteps some of these early strategies and aligns interests for innovators, biosimilars, and payers alike: PBMS are able to leverage their specialty pharmacies to move volume through discounted co-promotions. Biosimilars gain high-value access to PBMs’ large patient populations compared to other contracts, and innovators continue treating their patient populations at a discount. Co-promotions may even benefit patients if their treatment is uninterrupted, and cost-sharing reflects these deep discounts.

It is too early to say whether a co-promotion arrangement is the definitive biosimilar strategy. While the arrangement appears like a win-win-win across stakeholders, it is unknown exactly how the math works out for any particular party. Moreover, it is too early to tell whether the healthcare system or patients will experience savings from the new strategy. Will other PBMs and payers adopt similar strategies? Are co-promotions reasonable for all biosimilar molecules? How might co-promotions differ between private insurance and Medicare Part D where pharmacy networks are less impactful?

There is even a chance that co-promotions will hamper biosimilar savings by selecting only a few biosimilars to negotiate against an innovator. This could not only make discounting less aggressive but could also disincentivize some manufacturers from developing biosimilars altogether.