P-Loop mutations-Negative prognosticators in tyrosine kinase inhibitors resistant chronic myeloid leukemia patients

P-Loop mutations in CML patients prevent the conformational change in BCR-ABL1 necessary for drug binding. The present study aimed to evaluate the impact of mutations in this domain on the prognosis of the disease and also to associate the baseline Sokal relative risk score with the overall survival in non-responding CML patients.

Blood samples were analyzed using ARMS-PCR and then an association was assessed between presence/absence of mutations, hematological and molecular response, disease progression, overall survival, and Sokal score.

Of the total 250 CML patients, 102 were found to be treatment-resistant. Fifty-three patients harbored P-Loop mutations with G250E (12.7%) being most frequent. Complete hematological response and major molecular response were achieved by only 27.7% and 5.7 patients, respectively. Worst survival (57.1%) was observed in Y253H positive patients while according to Sokal score in high-risk patients harboring Y253F (50%) and E255V (50%).

The presence of P-Loop domain mutations negatively impacted the prognosis of the disease in terms of disease advancement and overall survival. So, the timely performance of the BCR-ABL1 mutational analysis and the modifications in the treatment plan based on the mutation identified would help in a better outcome of the disease.