KRASG12D-Mutated Metastatic Colorectal Cancer: Clinical, Molecular, Immunologic, and Prognostic Features of a New Emerging Targeted Alteration.

Abstract

KRASG12D mutation (mut) occurs in about 10%-12% of metastatic colorectal cancer (mCRC). Recently, novel KRASG12D inhibitors have been developed and are currently under investigation in phase I/II clinical trials in solid tumors including mCRC. We aimed at performing a comprehensive characterization of clinical, molecular, immunologic, and prognostic features of KRASG12D-mutated mCRC to inform the design and the interpretation of future trials. We performed a pooled analysis of phase III TRIBE and TRIBE2 studies comparing 5-fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI)/bevacizumab (bev) to doublets (5-fluorouracil, leucovorin, and oxaliplatin or 5-fluorouracil, leucovorin, and irinotecan)/bev. One hundred and thirty-six (16%) of 854 patients with available KRASG12D mutational status were KRASG12D mutated. KRASG12D-mutated patients had more frequently right-sided primary tumor and were less likely to present liver-only metastases with respect to other RAS mutated and all-wild-type (wt) patients. Compared with the BRAFV600E-mutated group, KRASG12D-mutated patients had more frequently left-sided primary tumor, resected primary tumor at the time of diagnosis, and Eastern Cooperative Oncology Group performance status 0. KRASG12D-mutated patients had better prognosis than BRAFV600E-mutated and worse prognosis than all wt patients. No prognostic difference was evident between KRASG12D mut and other <i>RAS</i> mut patients overall or according to other specific <i>KRAS</i> or <i>NRAS</i> hotspot mutations. No interaction effect was observed between KRASG12D mut and the benefit provided by FOLFOXIRI/bev compared with doublets/bev. <i>PIK3CA</i> mut were reported more frequently among KRASG12D-mutated tumors compared with both other <i>RAS</i> mut and all wt. A detail estimation of KRASG12D mut mCRC patients' characteristics and expected outcomes may be useful when planning future studies in this subgroup. The high prevalence of PI3K/PTEN/Akt pathway activating alterations may affect the efficacy of targeted strategies.