Other tyrosine kinase inhibitors
The reason as to why blast crisis is resistant to imatinib is the development of gene resistance where the gene responsible for the cancer changes itself or “mutates” to overcome imatinib. It may also multiply at an incredible rate. Thus, new drugs were developed, the second-generation tyrosine kinase inhibitors. They include nilotinib, dasatinib and bosutinib, and their main advantage lies in that they treat most mutations or “resistances” to imatinib and being able to treat blast crises with a better efficacy than imatinib.
Their main disadvantages are the adverse effects. For instance, some patients develop pleural effusion -a buildup of fluid around the lungs- and pericardial effusion -a buildup of fluid around the heart-. In addition, resistance may also develop against those agents.