Virtual patient analysis identifies strategies to improve the performance of predictive biomarkers for PD-1 blockade

Theinmozhi Arulraj1, Hanwen Wang1, Atul Deshpande2,3,4

  • 1Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205.

Insights

Predicting response to PD-1 inhibitors in metastatic triple-negative breast cancer (TNBC) is challenging. Early on-treatment biomarkers, particularly blood-based ones, show promise for improved patient selection and treatment efficacy.

Area of Science:

  • Oncology
  • Immunotherapy
  • Computational Biology

Background:

  • Metastatic triple-negative breast cancer (TNBC) patients exhibit varied responses to PD-1 inhibition.
  • Current predictive biomarkers for PD-1 therapy in TNBC have limited performance, hindering effective patient selection.
  • Quantitative systems pharmacology (QSP) modeling offers a novel approach to explore biomarker strategies.

Purpose of the Study:

  • To leverage in silico TNBC patient cohorts to identify improved predictive biomarkers for PD-1 inhibition.
  • To evaluate the performance of a wide range of potential biomarker candidates.

Main Methods:

  • Generation of in silico metastatic TNBC patient cohorts using a QSP model.
  • Integration of transcriptomic and clinical data to inform the QSP model.
  • Evaluation of 90 biomarker candidates using a cutoff-based testing algorithm and machine learning feature selection.

Main Results:

  • Combinations of pre-treatment biomarkers enhanced specificity but reduced sensitivity compared to single biomarkers.
  • Early on-treatment biomarkers, such as relative change in tumor diameter at two weeks, demonstrated superior sensitivity and specificity.
  • Blood-based biomarkers showed comparable efficacy to tumor- or lymph node-based biomarkers in identifying responders.

Conclusions:

  • Early on-treatment and blood-based biomarkers represent promising strategies for improving patient selection in TNBC immunotherapy.
  • Less invasive, blood-based biomarkers could facilitate more accessible patient stratification for PD-1 inhibitors.