The attention-deficit/hyperactivity disorder (ADHD) market across the seven major markets (7MM*) is forecast to decline at a negative compound annual growth rate (CAGR) of 0.8% from $11.9 billion in 2022 to $11.0 billion in 2032, driven by patent expiries, high generic uptake in the largest ADHD market, namely the US, and limited innovator entrants, according to GlobalData, a leading data and analytics company.

GlobalData’s latest report “Attention Deficit Hyperactivity Disorder (ADHD): Market Opportunity Assessment and Forecast to 2032”, anticipates a decline in sales growth across most ADHD drug classes. Specifically, stimulants (amphetamines, methamphetamines, and methylphenidates), and alpha-2a adrenergic agonists. The alpha-2a adrenergic agonists class is expected to see the greatest decline at a negative CAGR of 1.7% for the period of 2022-32.

Lorraine Palmer, Pharma Analyst at GlobalData, comments: “Due to the availability of the largest number of branded products, higher drug prices, and the largest ADHD population, the US market accounted for approximately 90% of the ADHD market in the 7MM at $10.7 billion in 2022. This is expected to rise to 91% by 2032. Among 29 branded ADHD products, 10 have US patent expiries between 2022-2032. It is estimated that these 10 products accounted for $3.5 billion in US sales in 2022.”

Additionally, two patent expiries are due to occur in Japan for Takeda’s Vyvanse (lisdexamfetamine dimesylate) and Intuniv (guanfacine hydrochloride). On the other hand, only Vyvanse’s patent is due to expire during 2022-32 in Germany, Spain, and the UK. France and Italy do not have any anticipated patent expiries of ADHD products within the forecast period.

Vyvanse, an amphetamine, has the largest overall revenues of all branded ADHD products, with approximately $2.5 billion in sales in the five major markets (the US, Japan, Germany, Spain, and the UK), where it was available in 2022. Its patent expired in the US in 2023 and generic lisdexamfetamine dimesylate products became available shortly after. However, they did not see the level of initial uptake typical to new generics in the US market due to shortages in active pharmaceutical ingredients (APIs), which negatively impacted the availability of generic products over branded agents to whom API manufacturers gave precedence.

GlobalData assumes the US API shortages are likely to be resolved by 2027, with generic uptake levels returning to normal. This will result in significant sales erosions of branded products.

Palmer continues: “The ADHD market is already crowded with inexpensive generics, which is due to expand with the upcoming patent expiries. This is likely to limit the uptake of novel market entrants. Thus, despite the anticipated launch of a few pipeline agents in the ADHD market in the mid-term, their impact on the overall market will only be moderate.”

There are four late-stage (Phase IIb/III) pipeline agents targeting core ADHD symptoms that include Cingulate’s CTx-1301, Axsome Therapeutics’ solriamfetol hydrochloride, Otsuka’s centanafadine SR, and Neurocentria’s NRCT-101SR. These are all anticipated to launch in 2026, together amounting to approximately $384 million in sales by 2032.

CTx-1301 is expected to steal patient share from long-acting methylphenidate products, while the three other pipeline agents are expected to compete against the marketed non-stimulants. However, all four pipeline agents are only forecasted to launch in the US market during the forecast period (although centanafadine SR is in phase I in Japan).

In addition, key opinion leaders (KOLs) in the US interviewed by GlobalData stated a hesitancy to use new products due to a perception that they typically do not provide any added benefits to what is currently on the market.

Palmer adds: “The pipeline agents due to launch are not looking to show improvements in efficacy above currently marketed products, but rather differentiation in terms of increased duration of action and reduction of side effects. Since pipeline agents are often priced at a premium upon entry into the market, KOLs have stated they fear the sharp rise of prices after initial promotion incentives are withdrawn. This makes inexpensive generic products the more attractive option.”

Rather than the launch of the pipeline agents, the most significant market driver is that, due to growing awareness, diagnosis and management of adult ADHD, total treated cases across the 7MM are expected to rise from approximately 10.7 million in 2022 to 11.1 million by 2032.

Palmer concludes: “Despite the launch of pipeline products and the overall increase in total treated cases, the barriers to market growth are expected to overwhelm the drivers. Principle among these barriers is patent expires and the launch and likely high uptake of generics.”