The increasing costs of cancer drug treatments have reached unsustainably high levels and may be harming patients, a group of experts has warned.

Many patients in the US with chronic myeloid leukaemia (CML) may being left under- or untreated because they cannot afford care, according to an article published in Blood, the Journal of the American Society of Hematology (ASH), supported by nearly 120 CML experts from over 15 countries on five continents.

"Patients with CML have a much better outlook today than ever before, thanks to advances that have greatly improved survival rates. But these patients now face dire financial struggles as they try to maintain their treatment regimen with the drastically inflating cost of care. And this issue likely extends to patients with other types of cancer who require ongoing treatment to maintain therapeutic benefit," said corresponding author Hagop Kantarjian, chairman of the leukaemia department at The University of Texas MD Anderson Cancer Center.

CML was selected as the focus of the Blood article because it is now considered a highly curable disease, thanks to the emergence of powerful, targeted tyrosine kinase inhibitors (TKIs); these allow patients to manage their disease with few symptoms by taking a well-tolerated pill, say the authors. 

Since TKI therapy was introduced over a decade ago, the annual mortality of CML patients has declined from 10%-20% in the early 2000s to just 2% today, and patients' estimated 10-year survival has increased from 20% to over 80%. Patients with CML, who were once told at diagnosis that they had a grim prognosis, are now enjoying close to normal lifespans as long as they receive and adhere to prescribed treatments, and the management of CML has become similar to that of chronic disorders such as diabetes and hypertension, say the experts.

However, they add, a key difference remains in the "extremely high" cost of CML drugs.

In the US, newly-approved CML drugs are priced substantially higher than older options, and the trend is consistent among other cancer types, they note. For example, of the 12 drugs approved by the US Food and Drug Administration (FDA) for various cancer indications in 2012, 11 were priced above $100,000 per year, while monthly cancer drug prices now average more than $10,000, almost double the levels of just a decade ago.

The overall cost burden on families is significant, as out-of-pocket cancer care-related costs comprise around 25%-30% of an average annual household budget. Cancer care-related costs contribute heavily to the unprecedented cost of health care in the US, now estimated at 18% of the nation's Gross Domestic Product (GDP) compared with just 6%-9% in much of Europe, the experts say.

"A major question we need to answer is how to determine the 'right' price for these drugs," comments Dr Kantarjian. 

“In many cases, it makes sense to let the market govern the price. However, when a product is directly related to a patient's survival over a period of years, it is critical to set a price that allows companies to profit and ensures that patients can afford their treatment. Since CML treatments must be taken on an ongoing basis, we are concerned that the surging prices are potentially harming patients," he warns.

Research suggests that up to 10% of patients in the US fail to take their prescribed drugs, largely because of cost concerns. And while US CML survival rates have improved in the last decade, the estimated survival remains at roughly 60%, suggesting that a portion of the population is not receiving adequate treatment, which may be related in part to the high cost of these therapies. By comparison, in Sweden, where costs are managed and compliance rates are high, CML survival rates are at least 80%, says the article.

The authors point out that advancing a long-term solution to this issue will require the participation of, and collaboration among, many invested parties, including treating physicians, patients, advocacy groups and pharmaceutical companies, as well as government bodies, insurers and pharmacies.

Collaborations will require agreement from a cooperative group on how best to manage the research process to control treatment costs, how the community can balance those investments, and how newly-approved products are priced in the market - similar to established processes in other countries around the world, they say.

"Identifying better ways to manage the cost of cancer care will require an evolution in thinking about current pricing-related policies and regulations, including those that limit price negotiation for Medicare coverage of treatments, as well as patent-related laws that limit the introduction of more affordable generic drugs," Dr Kantarjian adds.