This young guy may be in chronic phase CML due to blast count in the bone marrow, without typical cytogenetic aberrations seen in accelerated or blastic phase. I am wondering what are the other scores, especially EUTOS and ELTS (you have it on ELN webpage), and what is the main factor responsible for high Sokal (spleen, blasts, baso?). ELTS may help in estimation of risk of dying from CML even it not includes genetics. Unfortunately, monosomy 7 is quite strong adverse chromosomal change in hematology, often associated with myelotoxic effects like chemicals, irradiation etc, and therefore it raises many concerns in this case. With only trisomy 12 I would be more reluctant but with mono7, this guy is really at risk for further failure and progression.
The best treatment is to use the strongest TKI you have in local setting to suppress this Ph+ clone and to follow up strictly to ELN guidelines, with full karyotype and PCR at 3 and 6 months. Moreover, if his health insurance covers, I will start search for allogeneic donor (sibling and unrelated), because we can expect different scenarios.
In case you have possibility to perform mutation, do it, just to have information weather T315I is present or not, but it is not obligatory. Concerning TKI choice, it depends on resources. As you have started with imatinib and achieved CHR within one month of treatment, I probably would continue that up to 3 months evaluation. Probably, in case of having dasatinib, I would prefer that drug as choice in the first line setting. Nilotinib might be also OK. You have started imatinib 400, but in this case if only imatinib treatment available, I would probably use Imatinib 800 due to those adverse karyotype. Nevertheless, as you have CHR continue imatinib 400 with evaluation at 3 months (bone marrow blast count, karyotype, PCR) and in any not really optimal response, escalate imatinib to 800 or switch to another drug if available. I expect suboptimal response at best, and anything better is good for patient. In case of cytopenia and need for drug holiday I will put more efforts towards allogeneic transplant. I will not use any growth factor for shortening of neutropenia in such a case.
I am looking forward to have further follow up information.
Dr Andrija Bogdanovic, Belgrade, Serbia