Gleevec on way to being No. 1 treatment for CML

Our ‘cancer cousins’ can opt for Gleevec when standard treatment fails

Editor's note: As Life Rafters await U.S. approval of Gleevec for treating GIST, there's good news for our cancer "cousins" who take Gleevec for chronic myeloid leukemia (CML). Most of the following was taken from a Novartis press release earlier this month.

For years, interferon-alpha injections with cytarabine has been the standard treatment for newly diagnosed chronic myeloid leukemia (CML) patients. Recent clinical trial results could lead to a change in that approach.

An ongoing phase III study comparing Gleevec to the interferon-alpha plus cytarabine treatment showed that Gleevec resulted in a substantially higher response. Based on this finding, the independent data monitoring board (independent hematologists and a clinical statistician tracking the trial) recommended a change: CML patients on the trial who don't have significant response to the standard therapy will be told of the better results with Gleevec, and given the option to switch.

The changes to the clinical trial protocol have been communicated to investigators and patients this month. These changes allow patients who have not achieved a major "cytogenetic response" (the disappearance or reduction in the number of cancerous cells) after one year of treatment with interferon-alpha and cytarabine to switch to Gleevec. Patient consent forms will be changed to inform patients of the new data, and to urge them to speak with their physicians.

Called the IRIS study — International Randomized study of Interferon vs. STI571 (the original name for Gleevec) —– this large, international multicenter Phase III trial is evaluating Gleevec versus the combination of standard interferon and cytarabine as first line therapy in patients with chronic myeloid leukemia. Between June 2000 and January 2001, the ongoing study enrolled 1,106 patients in 177 centers across 16 countries. The study was designed to help determine the long-term outcome (including survival) of patients with newly diagnosed CML treated with Gleevec in comparison to the combination of interferon- alpha and cytarabine.

The independent data monitoring board further recommended that a formal, peer-reviewed presentation of the 12-month data results be made to the scientific community at the earliest possible opportunity.

Preliminary results from a different study of 47 newly diagnosed patients with early chronic phase CML showed that after three months of treatment, 77 percent (36 patients) had achieved complete or major cytogenetic responses. By comparison, previous studies of similar patients on interferon-alpha alone and interferon-alpha with cytarabine revealed just 24 percent of patients achieved complete or major cytogenetic responses after three months.

As with GIST patients on Gleevec, CML patients did suffer some side effects, most deemed mild to moderate. Treatment was discontinued due to adverse side effects in only in 1 percent of patients in chronic phase. The most common side effects: nausea, fluid retention, vomiting, diarrhea, hemorrhage, muscle cramps, skin rash, fatigue, headache, dyspepsia and dyspnoea.