Expensive treatments for rheumatoid arthritis, multiple sclerosis, cancer and, most strikingly, hepatitis C are pushing up costs to an unsustainable level.  

That is the key conclusion of the latest drug trend report from Express Scripts, the USA's largest pharmacy benefit manager. It notes that while growth in specialty drug spend in 2013 – 14.1% – was at its lowest point in the past six years, it is poised to go soar an additional 63% between 2014 and 2016.

Much of the analysis focuses on HCV treatments and specifically highlights Gilead Sciences' Sovaldi (sofosbuvir) which costs $84,000 for a 12-week course of treatment. Express Scripts forecasts that the USA will spend 1,800% more on HCV drugs in 2016 than it did last year and notes that "no major therapy class has experienced this high of a spending increase" in the 21 years it has measured thos type of data.

Speaking about Sovaldi, Steve Miller, chief, medical officer at Express Scripts, said that "never before has a drug been priced this high to treat a patient population this large, and the resulting costs will be unsustainable for our country". He claimed that "the burden will fall upon individual patients, state and federal governments, and payers who will have to balance access and affordability in a way they never have had to before".

Pricing 'unprecendented and unreasonable'

Dr Miller went on to argue that "the current pricing mentality around innovative products is unprecedented and unreasonable", adding that "standing side-by-side with many of the country's largest plan sponsors, we are going to drive toward a pricing environment that is fair for patients, payers and manufacturers".

Last month, US Democrats politicians asked Gilead to explain the price of Solvadi and discuss plans to improve access to low-income patients. The company has repeatedly justified the price on the grounds of the pill's cure rates, shorter treatment duration and excellent side effect profile compared to older medicines; many observers believe that Sovaldi will generate revenues in the region of $10 billion in 2014 alone.

The Express Scripts report also notes that while comprising less than 1% of all US prescriptions, specialty medications in 2013 accounted for 27.7% of the country's total pharmacy spend. Treatments for inflammatory conditions, such as rheumatoid arthritis and Crohn's disease, continue to rank as the most expensive specialty therapy class, driven by brand price inflation of 15% last year.

With an increase in spending of 14% in 2013, diabetes was the costliest drug class for the third consecutive year and the spend on these drugs is forecast to grow in the double digits over the next three years.