Sales of drugs to treat non-Hodgkin's lymphoma are set to more than double in value over the next decade, increasingin seven major world markets from around $4 billion in 2009 to $8.4 billion by 2019, according to new forecasts.

Growth in the seven markets - US, UK, France, Germany, Italy, Spain and Japan - will be driven by the launches of premium-priced therapies, but market development will also be tempered as a result of the introduction of biosimilar versions of rituximab (Roche/Genentech/Chugai Seiyaku/Zenyaku Kogyo's Rituxan/MabThera). These are set to commence in Europe during 2013, followed by launches in the US in 2015, according to the study, published by Decision Resources.

Biosimilar versions of rituximab will be available at lower prices than the branded product, says the report, which adds that, as a result of the widespread uptake of the product across all non-Hodgkin's lymphoma populations, the entry of biosimilar versions will cause a significant decline in sales of the branded product.

Nevertheless, despite the entrance of biosimilars, rituximab will maintain its dominance as the market-leading agent in the period to 2019, forecasts Decision Resources director Andrew Merron. 

He also points out that, as it attempts to reduce the negative impact of biosimilar erosion on its branded product, Roche has developed a novel anti-CD20 antibody - GA-101- plus a subcutaneous formulation of rituximab that should help soften the anticipated drop in sales of the branded, intravenously-delivered product.

Little in the way of new commercial opportunity remains for rituximab in the treatment of non-Hodgkin's lymphoma; however, the product's sales will increase to 2014 as its uptake continues to grow in the first-line maintenance setting for follicular lymphoma and as a single agent for newly-diagnosed asymptomatic follicular lymphoma, according to Decision Resources.

It also forecasts that sales of GlaxoSmithKline/Genmab's Arzerra (ofatumumab) will increase as a result of greater use in the wider non-Hodgkin's lymphoma patient population, while Celgene's Revlimid (lenalidomide) - an agent which is already widely used in multiple myeloma - and two novel kinase inhibitors - Pharmacyclics' PCI-32765 and Calistoga Pharmaceuticals' CAL-101 - are generating excitement among key opinion leaders. Together, they will contribute to significant sales growth in the non-Hodgkin's lymphoma drug market, following their expected launches beginning in 2014, it says.