Exploring Genomic Biomarkers for Pembrolizumab Response: A Real-World Approach and Patient Similarity Network

Marco Filetti1,2, Mario Occhipinti2,3, Alessio Cirillo2,4

  • 1Phase 1 Unit, Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, 00168 Rome, Italy.

Cancers
|December 17, 2024
PubMed

Insights

Never-smoking patients with advanced non-small cell lung cancer and high tumor mutation burden (H-TMB) may benefit from immune checkpoint inhibitor (IO) therapy if they have DNA Damage Response (DDR) pathway mutations. This finding could guide personalized treatment strategies.

Area of Science:

  • Oncology
  • Genomics
  • Cancer Research

Background:

  • Immune checkpoint inhibitor (IO) therapy is standard for advanced non-small cell lung cancer (aNSCLC) with PD-L1 ≥ 50%.
  • Smoking is linked to high tumor mutation burden (H-TMB) and response to IO, while never-smoking patients (NS-pts) often have low TMB (L-TMB) and poor response.
  • The molecular basis for H-TMB in NS-pts and their response to IO remains unclear.

Purpose of the Study:

  • To investigate the molecular characteristics of never-smoking patients (NS-pts) with advanced non-small cell lung cancer (aNSCLC) who exhibit high tumor mutation burden (H-TMB).
  • To identify potential genomic biomarkers predictive of response to immune checkpoint inhibitor (IO) therapy in this specific patient subgroup.
  • To explore the role of DNA Damage Response (DDR) pathway mutations in generating H-TMB and influencing IO outcomes in NS-pts.

Main Methods:

  • Retrospective analysis of 142 aNSCLC patients treated with first-line pembrolizumab, with PD-L1 ≥ 50%.
  • Next-generation sequencing (FoundationOne®CDx) to assess genomic alterations and correlate with clinical data and treatment outcomes.
  • Pathway enrichment analysis and patient similarity network construction, validated with data from POPLAR and OAK trials (853 patients).

Main Results:

  • Never-smoking patients (NS-pts) with high tumor mutation burden (H-TMB) were identified (8% of NS-pts).
  • H-TMB in NS-pts was enriched in DNA Damage Response (DDR) and β-catenin/Wnt pathway mutations.
  • The NS-pts subgroup with H-TMB and DDR mutations showed improved outcomes with IO therapy in both real-world and trial data.

Conclusions:

  • DNA Damage Response (DDR) pathway mutations may contribute to H-TMB in never-smoking patients (NS-pts).
  • A subset of NS-pts with H-TMB and DDR mutations demonstrates responsiveness to immune checkpoint inhibitor (IO) therapy.
  • DDR-based mutational profiling could identify NS-pts who may benefit from IO therapy, potentially improving prognosis.