Can you stop a cancer drug to see if you’re cured?

ASSOCIATED PRESS Rick and Nina Schlidt sit at the table of their home in Hartland, Wis. Nina Schlidt was diagnosed with chronic myelogenous leukemia in 2009 and had to take drugs to control it for six years. After she went into remission, she qualified for a study led by the Medical College of Wisconsin, allowing her to go off treatment completely.

Imagine you had a life-threatening cancer that a wonder drug had kept in remission for years. Would you risk quitting?

Thousands of people with a blood cancer called chronic myelogenous leukemia, or CML, now have that choice.

New treatment guidelines in the U.S. say certain patients can consider stopping Gleevec or similar drugs which were long thought to be needed for the rest of their lives. It’s just a pill or two a day but the drugs are expensive and have side effects.

A European study recently found it’s safe for carefully selected patients to try, and a U.S. study hoping to confirm that just finished enrollment.

“Our goal is to truly cure CML, which is essentially to have patients off drug,” said Dr. Ehab Atallah, a leukemia expert at the Medical College of Wisconsin who helps lead the U.S. study. “We’re hoping to figure out better who can and cannot stop.”

Some patients want to try, but others won’t dare.

“Like playing Russian roulette,” said Jee-Won Schally, 54, a former history teacher from Milwaukee who has taken Gleevec for 10 years and doesn’t want to stop.

Nor does Doug Jensen, 83, a retired engineer near Portland, Oregon, who still gets the drug for free because he was in the original study that proved it worked.

But for Nina Schlidt, quitting a similar drug nearly two years ago was wonderful and “financially, a godsend.” The 67-year-old suburban Milwaukee woman’s husband delayed retiring until 70 to keep insurance to cover her drug, which would have cost her thousands.

CML, which starts in the bone marrow, has long been unique. Some other types of cancer, such as breast or colon, are treated with surgery or a course of radiation or drugs and the tumor either is gone or not, and may or may not recur. But once CML develops, it has been considered a lifelong threat. It’s almost always caused by a gene flaw that usually develops during life.

Gleevec blocks the gene’s activity in more than 90 percent of patients. The drug’s approval in 2001 turned CML from a fatal disease to a chronic condition for most folks, and 36,000 to 100,000 Americans are living with it now, the Leukemia & Lymphoma Society estimates.

Two similar drugs, Tasigna and Sprycel, also are sold, and generic Gleevec came out last year. Treatment costs $60,000 to $150,000 a year. Even with insurance, copays run $1,000 to $24,000 a year, and Schally had to meet a $10,000 deductible.

Many patients want to quit because of side effects, but the thinking was they would always need treatment, the way some people need insulin to control diabetes.

Now, though, research suggests that long treatment may eliminate so many cells with the bad gene that the immune system may be able to keep the disease in check if it starts to return.

At an American Society of Hematology meeting in December, Dr. Francois-Xavier Mahon of the University of Bordeaux in France reported a study of 750 patients who stopped treatment after being in deep remission with no sign of disease in their blood for at least a year. After six months without treatment, 62 percent had maintained a deep remission, and 52 percent still had after two years. Most who relapsed were able to regain deep remission after resuming treatment, and none developed advanced disease, he said.

Half a dozen smaller studies have been done, and “the data are all the same and it all looks good,” said Dr. Kendra Sweet of the Moffitt Cancer Center in Tampa.