Two drugs top Gleevec in newly diagnosed CML

Gleevec (imatinib), the miracle pill for chronic myeloid leukemia, may soon have some competition after new research suggests two newer-generation drugs, Sprycel (dasatinib) and Tasigna (nilotinib), are more effective in patients with newly diagnosed CML.Two different studies presented today at the annual meeting of the American Society of Clinical Oncology found that giving Sprycel or Tasigna as first-line therapy resulted in faster, better responses compared with Gleevec. In one study, after a year of giving newly diagnosed patients either Sprycel or Gleevec, 77 percent of patients on Sprycel achieved a complete cytogenetic response compared with 66 percent of patients on Gleevec. A complete cytogenetic response signals the complete disappearance of all cancer cells from the bone marrow, and achieving this response within a year of starting treatment is associated with better long-term survival, said lead researcher Hagop Kantarjian, MD, of M.D. Anderson Cancer Center in Houston. Sprycel also had the advantage for another marker of drug effectiveness, called a major molecular response: 46 percent versus 28 percent.In the Tasigna study, complete cytogenetic response was seen in 80 percent of patients on Tasigna compared with 65 percent of patients on Gleevec after one year. The rate of major molecular response also tipped in Tasigna's favor: 44 percent versus 22 percent.Kantarjian, who was also involved in the Tasigna study, said both drugs resulted in fewer "bothersome" side effects, such as nausea, rash, and fluid retention, compared with Gleevec.Despite the promising results, he said some physicians may want to wait for the three- to five-year follow-up data that will look specifically at survival.Sprycel and Tasigna are currently approved for CML patients whose disease is resistant or intolerant to Gleevec, which occurs in roughly 30 percent of patients. The Food and Drug Administration is currently reviewing the approval application for Tasigna in newly diagnosed CML, and a decision is expected later this month. Bristol-Myers Squibb, the maker of Sprycel, plans to seek approval for its drug this year as first-line therapy for CML.And if that wasn't enough, results of a study comparing Gleevec to another next-generation drug called bosutinib are expected by the end of this year, said Kantarjian.Melissa Weber is the former managing editor of CURE and is covering the annual meeting of the American Society of Clinical Oncology.