Phase 2 Study of Azacitidine plus Pembrolizumab as Second-Line Treatment in Patients with Locally Advanced or Metastatic Pancreatic Ductal Adenocarcinoma
Mené sur 36 patients atteints d'un adénocarcinome canalaire du pancréas de stade localement avancé ou métastatique (âge médian : 62,5 ans), cet essai de phase II évalue l'efficacité, du point de vue du taux de réponse, et la toxicité d'un traitement de deuxième ligne combinant azacitidine et pembrolizumab
Background: Epigenetic regulators represent a novel strategy to modulate the tumor immune microenvironment in pancreatic ductal adenocarcinoma (PDAC). In preclinical models, DNA hypomethylating agents enhance cytotoxic T-cell infiltration, synergize with PD-1 blockade, and improve survival when combined with immune checkpoint blockade. This single-institution, phase II study evaluated the safety, efficacy, and biomarkers of azacitidine plus pembrolizumab in patients with previously treated PDAC.
Methods: Patients with locally advanced or metastatic PDAC after one prior regimen received 50 mg/m2 subcutaneous azacitidine on days 1-5 of a 28-day cycle, starting week 1, and pembrolizumab 200 mg intravenously every 3 weeks starting week 3. Baseline and on-treatment blood and tumor was collected for exploratory biomarker analysis.
Results: Thirty-six patients enrolled between October 2017 and September 2021 (median age: 62.5 years); 34 were evaluable for safety; 31 for efficacy. Treatment was generally well-tolerated, with Grade 1-2 fatigue and diarrhea most common AEs. Three patients (9.7%) had a partial response, and the disease control rate was 35.5%. Median progression-free and overall survival was 1.51 and 4.83 months, respectively. Exploratory analysis suggested higher baseline CD8+ T cells and lower tumor Ki-67 was associated with response, whereas low baseline CD8+ T cell and Granzyme B infiltration correlated with higher exponential tumor growth rate. PD-L1 and CD68 expression were not predictive of benefit.
Conclusion: Azacitidine plus pembrolizumab demonstrated limited clinical activity in second line, locally advanced or metastatic PDAC. Biomarker analysis suggests higher baseline CD8+ T-cell infiltration and lower proliferative index may identify patients more likely to benefit. (NCT03264404)
The Oncologist , résumé, 2026