The US treatment market for asthma will rise in value from $11.7 billion in 2013 to an estimated $14 billion by 2020, representing a Compound Annual Growth Rate (CAGR) of 2.6%, according to a GBI Research report.

The company’s latest report states that the US is the single biggest asthma treatment market globally, reflecting the country’s large population size, high disease prevalence and the inflated cost of therapeutics in comparison with other major markets.

However, according to Fiona Chisholm, associate analyst for GBI Research, the asthma therapeutics market will be strongly characterized by generic erosion that will impact several of the leading brands over the forecast period, including Singulair (montelukast sodium), Advair (fluticasone propionate/salmeterol xinafoate), and Symbicort (budesonide/formoterol fumarate).

Chisholm explains: “Singulair’s patent expired in 2012, with the US Food and Drug Administration subsequently granting approval to several manufacturers, including Teva, Sandoz and Mylan, to market generic versions of the drug. As a consequence, sales revenue for Singulair has declined substantially in recent years.

“Advair and Symbicort have also recently lost patent protection in the US. However, substantial generic erosion has not occurred, due to regulatory hurdles and the difficulties inherent in trying to produce a bioequivalent Inhaled Corticosteroid/Long-Acting Beta Agonist (ICS/LABA) combination drug and inhaler device.”

While patent expirations are set to limit market growth to 2020, the impact of this will be offset by the uptake of recently approved and promising pipeline drugs.

Chisholm continues: “Arnuity, the follow-on product to the current ICS market leader Flovent, was approved in the US in August 2014, while Relvar, the follow-on product to the current ICS/LABA market leader Advair, is at the pre-registration phase. GBI Research believes both drugs will help to maintain sales revenue for their respective classes.

“Furthermore, the potential approval of several premium-priced, novel IL-targeting monoclonal antibodies, although limited by their target populations, will also contribute to growth.”

The analyst adds that the development of these IL-targeting therapies, as well as other novel drugs, also gives rise to potential phenotype-targeted treatment, which could be particularly useful for patients with severe asthma.

“If approved, these drugs will represent a significant step forward in asthma therapeutics, helping to achieve personalized treatment tailored to each individual patient,” Chisholm concludes.