Abstract
Objective: To assess the efficacy and safety of azacitidine combined with lenalidomide in MDS patients and explore potential mechanisms of therapeutic response. Methods: Sixteen MDS patients with TP53 mutations received azacitidine plus lenalidomide at ZhongDa Hospital, Southeast University (January 2021-June 2025). Efficacy and safety were assessed, and TP53 mutation status was correlated with treatment response. Whole-transcriptome sequencing and bioinformatics were used to explore molecular biomarkers associated with therapeutic efficacy. Results: Sixteen patients (median age 69.5 years, range 52-82; 8 males, 8 females) were enrolled. According to the Molecular International Prognostic Scoring System (IPSS-M), 1, 2, and 13 patients were classified as median low, high, and very high risk, respectively. Among 16 TP53-mutated patients, 11 had biallelic mutations and 5 had monoallelic mutations. Overall response rate was 56.3% (9/16), composite complete remission rate (CRc) was 31.3% (5/16), and hematology improvement rate was 25% (4/16). Among TP53-mutated patients, the response rate was 56.3% (9/16), with variant allele frequency dropping from 65.6% to 16.5% in responders (P=0.017). In patients with TP53 mutations and complex karyotype, response rate was 53.8% (7/13), with 57.1% (4/7) showing disappearance of CK post-treatment. The most common grade 3-4 nonhematologic adverse events were infections (9/16, 56.3% ), including pneumonia (4/16, 25.0% ), gastrointestinal infections (3/16, 18.8% ), perianal infections (1/16, 6.3% ) and sepsis (1/16, 6.3% ). High CBX8 expression may be linked to treatment response. Conclusion: Azacitidine plus lenalidomide is an effective and safe therapy for MDS, including patients with TP53 mutations and complex karyotypes. Treatment markedly reduces TP53 variant allele frequency in responders, and high CBX8 expression may predict therapeutic response.