The present invention relates the stratification and treatment of patient suffering from a cancer. In this study, the inventors analyzed the adenosine methylation level of miR-125a-5p (m6A-miR-125a-5p) using RNA immunoprecipitation with an anti-methyl-base-antibody followed by qPCR. CLIP and ELISA were used to study the effect of m6A-miR-125a-5p on its ability to be recruited on GW182 and impact PD-1 expression, respectively. They showed that the METTL3-mediated m6A-miR-125a-5p regulates the expression of IGSF11/VSIG3 which acts as a molecular determinant of the immunogenicity of tumor cells. Observations in two lung cancer patients treated with anti-PD-1 therapy show that the m6A-miR-125a-5p level is analyzable from EVs/exosomes from longitudinal blood samples. These data provide that m6A-miR-125a-5p level can be used as a biomarker and therapeutic solutions (anti-IGSF11 antibody and METTL3 inhibitor) could potentially address the anti-PD1 therapy failure in a context of precision and personalized medicine intended for the right patient, at the right time, with the right therapy. Thus the invention relates to a method of identifying a patient having or at risk of having or developing a resistance to anti-PD-1 therapy based on the expression level of the extracellular vesicles adenosine methylated miR-125a-5p (m6A-miR-125a-5p).