The study proposes to correlate the plasma dosage of VEN with the inhibition of its Bcl-2 target during the first treatment cycle. VEN will be measured sequentially during the first treatment cycle and assess inhibition of its target by measuring the level of phosphorylation of Bcl-2 serine 70. In parallel, BH3 profiling will be evaluated sequentially. All these analyses will be correlated with treatment toxicity, response rate and overall patient survival. This pilot study will highlight the inter-individual variability of this AZA + VEN combination, and enable to launch a national study via the national cooperative groups to validate the results and thus ultimately propose a personalized treatment for patients benefiting from this combination.

Inclusion criteria :

• Patient with acute myeloid leukemia (AML) not eligible for intensive chemotherapy
• Patients aged 18 or over
• Patient treated with the combination azacitidine (AZA) + venetoclax (VEN)
• Patient having signed the study informed consent form
• Patient with social security coverage

Exclusion criteria :

• Patients receiving treatment inhibiting or inducing Cytochrome CYP3A4
• Presence of an active, uncontrolled infection
• Patient participating or having participated in a clinical drug trial in the month prior to inclusion.
• Vulnerable persons