Report on EHA 2014 – Part 1
European Hematology Association annual meeting, Milan, Italy, June 12-15, 2014
There are several large databases worldwide that track people with CML. One of the larger ones is maintained by EUTOS (European Treatment and Outcome Study), which collects information from 27 countries. According to the most recent update, the overall incidence of CML is about 1 case per 100,000 population per year, with the rate being slightly higher in males (Hoffmann and colleagues. EHA 2014; abstract P274). The highest incidence is seen in people aged 60-70 years (1.5 cases/100,000) and aged 70-80 years (1.7 cases/100,000).
The median age when CML was first detected was 57 years (Lindoerfer and colleagues. EHA 2014; abstract S680). About 95% of people had chronic-phase CML when they were diagnosed and most had no symptoms. Two-thirds were never-smokers. Overall, 84% of people started treatment with Gleevec, 11% with Tasigna and 4% with Sprycel.
How well did they do? At 8 years, the cumulative survival rate was 89% (Pfirrmann and colleagues. EHA 2014; abstract S1360). Among the 11% who died, the cause of death was about twice as likely to be something unrelated to CML compared to CML itself (7% vs. 4%).
The GIMEMA database in Italy has tracked how well people on TKI treatment have done over the long term (Castagnetti and colleagues. EHA 2014; abstract P276). About one-third of people stopped Gleevec at some point, with most starting Tasigna or Sprycel; 9% underwent bone-marrow transplant and 7% achieved a remission and were able to stop therapy. About 85% of people were alive after a median of about 6-7 years. Most deaths were due to something other than CML, such as another cancer, infection, heart attack or stroke, or respiratory failure. The proportion of people who died of CML was 6%.
Similar results were seen in the long-term follow-up of the German CML-Study IV (Kalmanti and colleagues. EHA 2014; abstract S676). After a median time of 6.5 years, two-thirds of people were still on treatment. The estimated 10-year survival rate was 84%. Remarkably, 89% of people achieved a major molecular response (MMR), and 74% had a 4.5-log reduction (MR4.5, essentially undetectable disease). Serious side effects occurred in 14% of people, but there were no Gleevec-associated deaths during the observation period. The most common side effects with Gleevec included edema (swelling, water retention), gastrointestinal problems (e.g. nausea), muscle or joint pain, rash and fatigue. Side effects were most common in the first three years of treatment, and declined in frequency thereafter.
A U.S. study found that 10-year survival among people treated with high-dose Gleevec (800 mg per day) was 91% (Sasaki and colleagues. EHA 2014; abstract P888). A total of 88% of people achieved MMR. The study also found that adding interferon-alfa injections to the regimen didn’t provide any additional benefit.
To put these numbers into perspective, a CML centre in the U.K. looked at how well people did before and after the introduction of TKIs in 2002 (Khan and colleagues. EHA 2014; abstract P910). Before Gleevec and the other TKIs, median survival after diagnosis was 2.3 years. After 8 years, the survival rate was 15%. For those diagnosed in the TKI era, 8-year survival has been 91%.