By Lila Rouland | Published on November 14, 2025 | 2 min read
The emergence of
immunotherapies, particularly
immune checkpoint inhibitors (ICIs), has revolutionized the management of many
cancers. However, only a
minority of patients derive durable benefit. Current
biomarkers such as
PD-L1 expression, tumor
mutational burden (
TMB), and
microsatellite instability (
MSI) have significant limitations in
sensitivity
and
specificity. To overcome these challenges,
large-scale transcriptomic
approaches offer a new opportunity to precisely characterize
tumor immune
phenotypes. This study proposes and evaluates
pan-cancer transcriptomic
classifiers capable of predicting response to ICIs, based on the integrative
analysis of multiple databases and clinical trials.
Can transcriptomic signatures outperform PD-L1
and TMB?
The authors analyzed
47 gene expression
signatures across more than
10,000 tumors from 33 cancer types using data from
The Cancer Genome Atlas (TCGA). These signatures were grouped into functional
categories (adaptive immunity, inflammation, angiogenesis, etc.) and integrated
into supervised models using machine learning algorithms such as random forest
and elastic net regression.
Three main classifiers were developed:
- Pan-Immune Classifier (PIC): based on 11
signatures related to immune activation.
- Tumor
Microenvironment Classifier (TMC): based on 14 signatures related to stroma,
angiogenesis, and metabolism.
- Combined
Classifier (PIC + TMC): an integrated approach capturing both immune and non-immune
dimensions of the tumor ecosystem.
These models were tested and validated in seven
independent clinical cohorts treated with ICIs (including MCC, BLCA, NSCLC,
melanoma, etc.), comprising over 1,500 patients. Both the PIC and the
combined model demonstrated superior predictive performance compared to
PD-L1, TMB, and classical IFNγ-based classification, achieving an area under the curve (AUC) of up
to 0.79 in some cohorts.
For instance, in the IMvigor210 cohort
(urothelial carcinoma), patients classified as “high PIC” had an objective
response rate (ORR) of 53%, compared with 12% in the “low PIC”
group. Similar trends were observed in the MCC cohort, where highly classified
patients experienced a clear improvement in overall survival.
The study also showed that these classifiers
were robust to technical variability and could be applied to standard
RNA-seq data from FFPE samples, reinforcing their clinical applicability.
Furthermore, the analyses revealed that the models capture signals beyond the
mere presence of immune cells, incorporating the functional state of the
tumor microenvironment.
Toward a universal transcriptomic score to
guide immunotherapy?
The findings suggest that multi-signature
transcriptomic classifiers provide a finer stratification of patients
eligible for immunotherapy than traditional biomarkers. Integrating the PIC,
TMC, and their combined model into clinical decision-making algorithms could
transform patient selection, preventing unnecessary, costly, and ineffective
treatments.
However, several challenges remain: these
models need prospective validation, analytical standardization,
and integration into clinically accessible platforms. Further research
is also required to combine transcriptomic data with genomic and imaging
biomarkers, paving the way for multimodal predictive models.
In summary, this study represents a major step
toward precision immuno-oncology, enabling clinicians to predict,
select, and tailor immunotherapeutic treatments based on the patient’s global
transcript.
Read next: TNBC: exploring the global landscape of biomarkers and therapeutic prospects
About the author – Lila RoulandDoctor of Oncology, specialized in Biotechnology and Management
With dual expertise in science and marketing, Lila brings her knowledge to the service of healthcare innovation. After five years in international academic research, she transitioned into medical and scientific communication within the pharmaceutical industry. Now working as a medical writer and content developer, she is committed to highlighting scientific knowledge and conveying it to healthcare professionals with clarity and relevance.