AbbVie's Humira finally faces biosimilar challenge in US

AbbVie's cash-cow immunology product Humira has its first biosimilar competition in the US market with the launch of Amgen's copycat product Amjevita, several years after it was approved by the FDA.

In an unusual move, Amgen's drug is being introduced onto the market with a two-tier pricing system, exemplifying once again the fiendishly complex underpinnings of the US prescription drug market.

A sizeable 55% discount to Humira (adalimumab) comes into play in one iteration – $1,557 per 40 milligram pen device for a two-week supply – while the other provides a much-smaller 5% reduction to $3,288, but will attract a higher rebate rate.

Why the double system? Amgen said the objective is to "provide broad access for patients by offering two options to health plans and pharmacy benefit managers."

The company reckons the high list price will be favoured by PBMs, whose business model has been set up to work around a rebate model, while the lower price should appeal to health systems that operate as both an insurer and a care provider.

Humira remains the best-selling pharmaceutical product of all time, although it has started to retreat having already come under pressure from biosimilars in other markets outside the US. Sales were up slightly to $16.4 billion in the first nine months of 2023, with a 21% decline in international sales offset by a 6.5% gain to $13.6 billion in the US.

AbbVie has said it doesn't expect the launch of Amjevita to have a massive impact on revenues this year, as Amgen's drug will be the only biosimilar in the market for six months – thanks to a settlement agreement to resolve patent litigation between the two companies in 2017.

During that period, AbbVie will pay royalties to AbbVie, as both companies prepare for the entry of several more Humira biosimilars later this year.

The big impact on the brand – which made $20.7 billion in 2021 – is expected to take place in 2024, but AbbVie has said it will not make predictions for 2023 until its fourth-quarter update on 9th February.

On its third quarter results call, the company said it had made strenuous efforts to position Humira preferentially on US formularies this year and anticipates "strong access" for the drug. In 2024, AbbVie is modelling a 45% impact, give or take 10% either way, but has said newer immunology drugs like Skyrizi (risankizumab) and Rinvoq (upadacitinib) are to make up the shortfall from 2025 onwards.

The company is predicting 2022 sales of $7.5 billion for the two drugs, and recently raised its peak sales expectations for Skyrizi alone to $5.1 billion.