The Danish medical system saved 82.8% on adalimumab by switching almost all patients from the reference product to biosimilars, but such a benefit for the US healthcare system may not be possible, according to a new study.
A Danish study suggests that the patent blockade preventing adalimumab biosimilars from reaching market in the United States is hugely expensive for consumers and the healthcare system.
By switching to biosimilar adalimumab, the Danish healthcare system was able to slash costs by 82.8% and sustain that for more than a year, even though use of adalimumab significantly increased over the same period.
In the United States, patent battles have stalled the arrival of biosimilars to reference adalimumab (Humira) until 2023. However, in Denmark where AbbVie’s exclusivity for adalimumab expired in October 2018, the Danish Medicines Council immediately switched to biosimilars for all indications of the reference product. The country also switched patients who were already using the reference agent.
Prior to October 2018, Denmark used Humira exclusively, at a cost that averaged $5 million per month. For the year ending October 2019, biosimilars were used almost exclusively and per-month costs consistently hovered close to the $1 million mark.
Also prior to AbbVie’s loss of exclusivity in Denmark, the country was using roughly 8000 prefilled syringes (pens) of reference adalimumab each month. From October 2018—the point of exclusivity loss—to October 2019, use of adalimumab pens increased to roughly 13,000 per month, with only a very small fraction of those pens being the originator product.
“Access to generic and biosimilar drugs is generally needed to ensure market competition and lower drug prices,” wrote the authors of the Danish study. They noted that many factors may prevent the use of biosimilars in the United States, including lack of automatic substitution of agents, drugs not being included on formulary, and manufacturers withdrawing discounts on originator drugs if payers use biosimilars (rebate traps).
The authors noted that AbbVie had US market net revenue of $3.9 billion from Humira in the third quarter of 2019. The drug is the world’s top-selling medicine, with $19 billion in annual revenue in 2018.
“Thorough preparation and multidisciplinary collaboration between all stakeholders were key points in the Danish implementation, and they are crucial for successful implementation in the United States,” the authors wrote.
They said it is possible that by the time reference adalimumab loses exclusivity in the United States, in 2023, the window of opportunity for biosimilars of this product may have closed, because follow-on products may have picked up market share from Humira.
“The lack of adalimumab biosimilars results in substantial premiums being paid by patients and payers when much cheaper biosimilar drugs are available outside the United States,” the authors wrote.
The Denmark health system used 3 adalimumab biosimilar brands, 1 for pediatric patients and 2 for adult patients, following discontinuation of Humira use.
Costs of adalimumab dropped 82.8% from September 2018 to December 2018 (September, 8197 pens at $5.13 million; December, 9438 pens at $1.01 million). The proportion of biosimilars used in December 2018 was 77.9% (438 of 562 pens) for pediatrics, 94.7% (4348 of 4590 pens) for adults in Western Denmark, and 97.7% (4188 of 4286 pens) for adults in Eastern Denmark.
The authors said there were no significant differences in proportions of biosimilars used between dermatology, gastroenterology, and rheumatology.