US prescription drug sales grew 5.4% to $251.8 billion in 2005, compared with $238.9 billion in sales the previous year, according to healthcare information firm IMS Health. The sales figures are derived from IMS’s National Sales Perspectives and National Prescription Audit offerings, respectively, the company said in a news release. IMS charted 2005 US market performance by categories including distribution channels, therapy classes, prescription products and companies. Among the highlights: • Biotech products remained a major growth engine in 2005, with sales increasing 17.2% to $32.8 billion. Contributors to this growth included Aranesp, Enbrel and Neulasta, all from Amgen, as well as Genentech’s Rituxan. • Within the biotech market, a number of new rheumatoid arthritis drugs were launched successfully over the past few years, including Amgen’s Enbrel, Centocor’s Remicade and Abbott’s Humira. • Among the notable new products launched in 2005 were potential blockbusters, including Eli Lilly’s Byetta for type 2 diabetes, Pfizer’s Lyrica for neuropathic pain and seizures and Sepracor’s Lunesta for long-term treatment of insomnia. • Seven new products with potential global blockbuster status are expected to launch in the US in 2006, including a number of standouts: Sanofi-Aventis’ Acomplia (for obesity), Pfizer’s Sutent (for cancer), Pfizer’s Exubera (inhaled insulin for the treatment of type 1 and type 2 diabetes) and Pfizer/Neurocrine Biosciences’ Indiplon (for insomnia). These new product introductions will help offset some of the $18 billion in sales at risk for products losing patent protection in 2006. • The mail service channel grew more rapidly than retail distribution channels for US prescription drugs in 2005. However, rates of mail order growth are expected to slow and retail growth to increase in 2006. • Pfizer’s cholesterol reducer Lipitor remains the highest-selling product in the US for the fifth consecutive year, while AstraZeneca’s Nexium, Sanofi-Aventis/Bristol-Myers Squibb’s Plavix, Amgen’s Enbrel and Amgen’s Aranesp all delivered double-digit growth. • The rank order by US sales of the top five pharmaceutical companies in 2005 remains unchanged, with Eli Lilly joining the top 10.