July 11, 2024

Biosimilars have been on the market for almost a decade now. But the first biosimilar that had a high impact on the pharmacy benefit launched in 2023 with Humira (adalimumab). While biosimilars offer great potential for savings, the launch of adalimumab revealed challenges with biosimilars that slow their uptake. It is important for plan sponsors to understand challenges with biosimilars as more of these products hit the pharmacy benefit in the next five years.

Challenge 1: Provider and Patient Perception

Despite a mountain of evidence that they are safe, including from the FDA themselves, providers and patients still report being uncomfortable with biosimilars. While biosimilars are different than generic medications, there is no meaningful difference in safety of efficacy compared to the brand name medications.

However, providers are not willing to prescribe them with confidence. And patients are not willing to use them to the same extent as they do generic medications. As a result, the more expensive brand name medications continue to dominate utilization share.

Challenge 2: Interchangeability

Currently, biosimilars do not come to market as interchangeable with the brand name product. To understand why, it is important to define interchangeability. Within the pharmacy space, interchangeability means that when a provider prescribes the brand name product, the pharmacist can swap it for the biosimilar.

With generic products, this happens at high rates. For biosimilars, regulatory rulings have made this process cumbersome — leading to slower uptake. Biosimilars must seek approval as interchangeable on top of proving they are safe and effective. This process can cost the manufacturer millions in additional studies so unfortunately, they often forgo this step.

The lack of interchangeability leads to operational nightmares at the pharmacy. Additionally, it can feed into the perception that biosimilars are somehow inferior to generics. To support the uptake of biosimilars, the FDA is working on making this designation easier to achieve, and Congress is working on ways to remove the need for this designation all together.

Challenge 3: Manufacturer Factors

The number of manufacturers jumping in with adalimumab biosimilars has caused some challenges, but other factors with manufacturing have had more impact.  First amongst concerns has been the supply chain. Providers and PBMs will quote the potential for shortages as the reason to stay with brand name Humira. However, shortages have yet to materialize.

Another factor that had the potential to impact patients is the manufacturers’ approach to patient assistance. Humira previously had a robust patient assistance program and a manufacture co-pay assistance card. In recent years, the manufacturer has limited the availability of assistance, but many members were receiving Humira for little to know cost. Overall, the cost of biosimilars can offer as much as an 86% savings over Humira. However, concern about shifting in member responsibility has been viewed as a barrier. This can be overcome with intentional plan design.

Another factor creating complexity in this space is manufacturer pricing strategy. Manufacturers launched the exact same biosimilar product with up to 3 price points. This pricing model was intended to provide options, but the result has been confusion. Worse yet, it has resulted in selections that don’t always benefit the plan sponsor or members.

Challenge 4: PBM Factors

Arguably the most significant challenge with biosimilars in the pharmacy benefit space has been factors within the plan’s pharmacy benefit manager.

Members can only get access to medications that are on their formulary. For Humira biosimilars, formulary access has been difficult. The manufacturer of brand name Humira greatly increased the rebates on the brand agent in an attempt to lower the net cost. The rebates for other medications were also tied into Humira’s increases in rebates. This created situations where even when biosimilars were placed on a PBM formulary, they were done so at parity with Humira. This creates limited incentives to switch. This approach appealed to PBMs who have misaligned incentives when it comes to rebates.

The combination of these decisions has led to a retained market share for brand name Humira. In February 2024, more than a year after the launch of the first biosimilar, Humira still had 96% of the market share. Further proof that PBM decisions impact biosimilars showed up in April of 2024. CVS Caremark removed brand name Humira in favor of its own lower cost biosimilar. The impact of this decision led to a more rapid uptake of that specific biosimilar. By May 2024, Humira’s market share dropped to 81%, largely attributed to this one PBM’s formulary decisions.


The challenges with biosimilars may feel daunting. The good news — there are ways for plan sponsors to leverage the potential savings from biosimilars on the pharmacy benefits. At Innovative Rx Strategies, we can help clients engage with their PBMs to maximize savings through biosimilars and ensure processes are in place that benefit plan sponsors and their members. Please reach out to learn more about how we can support.

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