Before the second-generation TKIs (Sprycel, Tasigna, Bosulif) became available, the best option for people with an inadequate response to Gleevec was to give more Gleevec. So many studies used twice the usual dose (or 800 mg per day).
A new study has looked at whether this strategy was successful (Liu and colleagues. J Cancer Res Ther 2016;12(Supplement):23-26). The researchers pooled the results of seven studies that compared high-dose Gleevec with the usual dose (400 mg per day) in over 2,000 people.
According to this analysis, more was better – people taking the higher dose were 75% more likely to achieve the milestone of a complete cytogenetic response (roughly a 2-log reduction in BCR-ABL transcripts) within the first 6 or 12 months of treatment.
However, success came at a cost. More Gleevec meant more side effects. There was a significantly higher risk of knocking out other blood cells, such as neutrophils and platelets. Low neutrophil counts (called neutropenia) is often associated with infections; while a low platelet count (called thrombocytopenia) is associated with bruising and delayed healing.
With these kinds of side effects, it appears that a better option for people who don’t respond to Gleevec is to switch to a higher potency medication, such as Sprycel, Tasigna or Bosulif.