Variation in FOLFOX, FOLFIRI, and FOLFOXIRI effects on CD8+ T cell and PDL1 levels in MSS CRC patients


Lindsey Carlsen, Andrew Elliott, Marzia Capelletti, Emil Lou, John Marshall, Heinz-Josef Lenz, Philip Philip, Michael Hall, George Sledge, Alexander Raufi, Rimini Breakstone, Khaldoun Almhanna, Benedito Carneiro, Howard Safran, Wafik El-Deiry


  • Immunotherapy remains ineffective for patients with MSS CRC.
  • There is an association between FOLFOX and high tumor infiltrating CD8+ T cell levels.
  • CD8+ T cell levels and PD-L1 expression do not predict survival in FOLFOX-treated patients.
  • There is an association between high PDL1+ rates and RCRC, BRAF-mut CRC, and FOLFIRI-treated L-CRC.

Future Directions

  • We are currently investigating:
    • Various chemotherapy + immunotherapy treatment schedules in vivo to identify optimal strategies for patients with MSS CRC.
    • Immune cell activation state along the course of chemotherapy treatment in patients with MSS CRC.
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