Newer Drugs Beat Gleevec for Leukemia
Sprycel, Tasigna May Become Options to Treat Newly Diagnosed Chronic Myeloid Leukemia
Tasigna vs. Gleevec
In the second study of 846 patients, cancer cells were almost completely wiped out in the bone marrow of about 80% of patients on Tasigna by one year, compared with 65% of patients on Gleevec. The rates of major molecular response were about 44% and 22%, respectively.
Tasigna "produced more responses and better outcomes for patients," says study head Giuseppe Saglio, MD, of the University of Turin, Italy.
All three drugs "have outstanding safety profiles," Charles Sawyers, MD, of Memorial Sloan-Kettering Cancer Center in New York, writes in an editorial in the New England Journal of Medicine. There are modest differences in side effects that may lead one patient to choose one drug over another, he writes.
For example, muscle cramps and fluid retention are more common with Gleevec, while changes on liver function tests are more common with Tasigna, he writes. Rashes and headache were more common among both Sprycel and Tasigna users than among patients on Gleevec in the new studies.
But one-year results may make it too early to "claim complete victory" against CML, Sawyers writes.
Ironically, it may come down to economic considerations, he writes, noting that Gleevec could become available in a much cheaper generic form when its patent expires in a few years.
Currently, a month's supply of Gleevec costs about $4,200, and Tasigna can run $7,900 per month, according to Novartis, which makes both drugs.
Smith says that based on the research to date, the FDA is expected to consider approving both newer drugs for newly diagnosed patients.
Another targeted CML drug, bosutinib, made by Pfizer, is also in testing.