Patients suffering from chronic myeloid leukemia (CML)-- a rare form of cancer -- can get huge financial benefits if they start using the generic form of drug Gleevec, the patent of which expired in January this year, a study said.

"If we start all patients on the generic form of Gleevec and it works, then they are on a generic for the rest of their lives," said lead author William V. Padula, an assistant professor at the Johns Hopkins University. "This amounts to a huge cost savings for them and their insurers," he added.

The study, published recently in the Journal of the National Cancer Institute, said if all CML patients were started upon diagnosis on the generic form of Gleevec, known as imatinib, the cost of treatment per patient over five years would be nearly $100,000 less than it is now.

While Gleevec was the first drug to successfully treat CML, two other drugs in the same category - dasatinib (sold as Sprycel) and nilotinib (sold as Tasinga) - have come on the market in recent years.

Generic versions of these drugs will not be available for many years and the branded versions cost roughly $75,000 each for a year's supply.

In nearly 90 percent of cases, patients are now started on one of these newer drugs based on each physician's preference, but research has shown that overall five-year survival rates of all three drugs are equivalent.

Padula's team found that if insurers decided to only pay for Gleevec as the first line drug -- instead of allowing doctors to choose -- the savings would be even greater than $100,000 over five years if the patient stayed on Gleevec for the entire time.

This five-year time point is significant since it is the amount of time hematologists and oncologists typically use to measure progression-free survival or overall survival from remission in CML patients.

"There is minimal risk to starting all patients on imatinib first," Padula said.

"If the patient can't tolerate the medication or it seems to be ineffective in that patient, then we can switch the patient to a more expensive drug. Insurance companies have the ability to dictate which drugs physicians prescribe first, and they regularly do. Doing so here would mean very little risk to health and a lot of cost savings," he added.