Page 37 - IJSA, Vol. 4, No 2, 2021

International Journal of Science Annals, Vol. 5, No. 1-2, 2022
рrint ISSN: 2617-2682; online ISSN: 2707-3637; DOI:10.26697/ijsa

quantitative and qualitative factors (Bonifacio et al., underscoring the limitations of imatinib in treating a
2019). more aggressive disease.
Acute biphenotypic leukaemia (ABL) is uncommon and Numerous initial variables at the time of CML diagnosis
predominantly affects children. ABL has no have been linked to various probabilities of progression.
predetermined diagnostic standards (Ivanov et al., 2020). Current prognostic models identify high-risk patients
The BCR-ABL1 inhibitor has no effect on the various who are more likely to develop AP-CML or BP-CML.
leukaemia cells (mainly cells of the granular chain) in The EUTOS long-term survival (ELTS) score, in
CP-CML, whereas TKIs are mostly focused at the instance, indicates three risk categories with significantly
progenitor cell group. It is very predictive to use CD34 varying risks of death from progression in advanced
expression. The expression of CD34 might fluctuate from phase.
time to time, and this variation may be caused by the The kinetics of response to treatment is the most
sensitivity of the monoclonal antibodies used, as well as important indicator of progression. Numerous studies
by technical considerations (such as the sensitivity of the have shown that failure to diminish BCR-ABL1 by 10%
flow cytometry method) and the standards used to obtain after three months is associated with a higher risk of
a positive result. progression to the advanced phase and worse survival
CML blast crisis (CML-BC), despite recent when using frontline imatinib and 2nd generation TKIs.
advancements in the treatment of early-stage illness, During the first several months of treatment, measuring
continues to provide a therapeutic challenge. Less than the BCR-ABL1 transcript halving time may help to
30% of patients with CML-BC respond to normal improve the sensitivity and specificity of response
induction chemotherapy, making it highly resistant to the measurement.
condition. When compared to de novo acute leukaemia, Finally, patients who receive consistent, standardised
conventional chemotherapy has been substantially less monitoring are at a decreased risk of progression than
effective in treating this illness, with non-responders those who receive less frequent monitoring. Despite
having a mean survival time of only 2 to 4 months proper monitoring and an apparent satisfactory response
following diagnosis of blast crisis. In CML-BC, to TKI, abrupt onset of BP may occasionally happen. We
numerous chemotherapy regimens have been explored, believe that all newly diagnosed CPCML patients should
with varying degrees of effectiveness. Although imatinib preferably receive frontline treatment based on the ELTS
was studied in individuals with CML-BC, the majority of scoring system, and non-low-risk patients should be
CML-BC instances currently occur in patients who are given consideration for 2nd generation TKIs or closely
already receiving imatinib-based therapy and going monitored for an early molecular response when imatinib
through the blastic phase as a result. As a result, there is is chosen as the treatment of choice (Bonifacio et al.,
no established standard of care for CML-BC patients. 2019).
The future course of new treatment modalities will be
decided by further research into the molecular Conclusions
transformation processes of chronic-phase CML-BC and Identification of the blast lineage of patients with CML –
strategies to address these molecular abnormalities. blast crisis is crucial since the existence of atypical blast
Despite significant efforts, the prognosis for CML in the phenotypes influences the treatment strategy. Flow
blast catastrophe remains depressing. Currently, cytometry with an extended panel of antibodies is utilized
extending the chronic phase and postponing the start of to assist in blast lineage determination and detection of
the blast crisis is the most effective way to increase aberrant antigen expression in CML – blast crisis.
survival in CML (Esfahani et al., 2006).
A TKI treatment was recommended before allogeneic Acknowledgments
SCT for all patients in advanced phase in earlier ELN We are thankful to the Indian Council of Medical
treatment guidelines. Especially for AP patients, most Research, New Delhi, India, and Mr. Hirendra Rajwanshi
recent guidelines recognised the value of frontline TKI and Mr. Devendra Singh for their technical support in
treatment without the necessity for a future transplant. flowcytometry procedure and laboratory-related work.
Both ELN and NCCN advise treating newly diagnosed
AP patients with TKI alone; transplantation is only Ethical Approval
considered as a last resort for those who do not respond This study had been approved by the Institutional Ethics
to treatment as expected. Only imatinib 600 mg daily has Committee, King George’s Medical University,
a market authorisation in the European Union for Lucknow, India (No. 461/Ethics/2022 from 06.06.2022).
frontline use in newly diagnosed patients in advanced
phase, although this drug’s efficacy is constrained by the Funding Source
emergence of BCR-ABL1 kinase domain mutations, This research did not receive any outside funding or
which are more common in this situation than in CP. Both support.
retrospective and prospective trials have shown the high
efficacy of frontline treatment with nilotinib or dasatinib, References
as well as the impressive DMR rates. Intriguingly, in the Arber, D. A., Orazi, A., Hasserjian, R., Thiele, J.,
randomised prospective studies on CP patients, the Borowitz, M. J., Le Beau, M. M.,
amount of benefit from 2nd generation TKIs over Bloomfield, C. D., Cazzola, M., &
imatinib was more pronounced in high-risk patients, Vardiman, J. W. (2016). The 2016 revision to the

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