TRENTON, N.J. — Astronomical prices for breakthrough cancer drugs are pushing up treatment costs for patients as well as insurers, making it tougher for patients to complete lengthy therapy at a time when it’s increasingly effective.
Global spending on cancer medicines hit $91 billion last year, up from $71 billion in 2008 and $37 billion a decade ago, according to a report from the IMS Institute for Healthcare Informatics. That’s despite factors that have slowed the average annual increase in cancer drug spending to 5.4 percent over the past five years, down from 14.2 percent increases each year from 2003 to 2008.
‘‘We’ll cross [the $100 billion] threshold in the next year or so,’’ predicted Murray Aitken, the institute’s executive director. That amount would be about 10 percent of worldwide spending on all prescription drugs.
In the United States, a month’s supply of a brand-name cancer drug is now about $10,000, double what it was a decade ago, according to the report. The most expensive drug, at $117,648 for a course of treatment, is Bristol-Myers Squibb Co.’s Yervoy, the first drug to prolong survival in patients in advanced stages of the skin cancer melanoma.
Treatment is costing US patients more partly because of sweeping changes in the health care system.
Employer-based insurance plans increasingly are shifting onto patients much higher copayments and deductibles — the amount patients must pay before insurance kicks in. More patients buying their own insurance have been choosing plans with high deductibles, a strategy to reduce monthly premiums.
And many cancer specialists are giving up private practice to work for hospitals, which because of their high overhead usually charge at least twice as much for each infusion of chemotherapy drugs as a doctor’s office. Aitken noted that patient out-of-pocket costs can exceed $2,000 per dose, although patient assistance and other programs can help.
On average, an insured patient’s total outlay for a year’s cancer treatment is about $9,000, excluding any assistance programs, with the insurance company covering the remaining $115,000, according to Aitken. Patients receiving older cancer drugs available as generics would pay less.
The higher the patients’ costs, the more likely they are to drop out of treatment before finishing. For example, the report notes that when copayments for hormonal breast cancer treatment exceed $30, there is a 10 percentage point drop in the number of patients who complete therapy, compared with when the copay is $30 or less. For patients who stop therapy and resume it later, the combined patient and insurer costs can jump 50 percent.
For those who complete treatment, there’s a higher chance of surviving longer, partly because newer cancer drugs target individual cancer cells rather than indiscriminately killing healthy cells while attacking tumors.
‘‘The willingness to pay for these breakthrough drugs is strong,’’ Aitken said. Overall, the five-year survival rate for all cancers combined in the United States climbed from about 57 percent in 1990 to about 65 percent.