Novel Proteomics Test PROphet Shows Promise in Guiding Lung Cancer Immunotherapy Decisions
Key Insights
The PROphet (search) proteomics test demonstrates potential to enhance PD-L1 (search) testing accuracy in lung cancer (search), helping identify patients who would benefit most from immunotherapy versus combination treatments.
Poor prognostic biomarkers like STK11 (search) and KEAP1 (search) mutations are emerging as important indicators for treatment selection, particularly in determining the need for triple combination therapy.
Liquid biopsies measuring circulating tumor DNA show promise in monitoring treatment response and could help guide real-time therapy adjustments in lung cancer (search) patients.
The landscape of biomarker testing in lung cancer (search) treatment is evolving beyond traditional PD-L1 (search) expression analysis, with new proteomics-based approaches showing promising results in treatment selection. The plasma proteomics-based PROphet (search) test has emerged as a potential complement to standard PD-L1 testing, offering improved accuracy in predicting immunotherapy response.
Advancing Beyond PD-L1 Testing Limitations
Current PD-L1 (search) testing, while standard practice, has shown significant limitations. Dr. Luis Raez, Medical Director and Chief Scientific Officer of Memorial Cancer Institute (search), highlights that even among patients with PD-L1 expression above 50% - traditionally considered optimal candidates for immunotherapy - only about 40% respond to treatment.
The multicenter PROPHETIC trial has demonstrated that combining PD-L1 (search) testing with plasma proteome analysis can better stratify patient outcomes. Notably, patients with high PD-L1 expression (≥50%) who tested PROphet (search)-negative showed significantly improved survival with chemoimmunotherapy compared to immunotherapy alone (HR, 0.23; 95% CI, 0.1-0.51, P < .0003).
Role of Poor Prognostic Biomarkers
Research has identified several poor prognostic biomarkers that are reshaping treatment approaches. Patients with STK11 (search) or KEAP1 (search) mutations typically show poor response to single-agent immunotherapy. For these patients, data from the POSEIDON trial suggests that a triple combination approach using anti-CTLA-4 (search) and anti-PD-L1 (search) inhibitors plus chemotherapy may be more beneficial.
Emerging Role of Liquid Biopsies
Circulating tumor DNA (ctDNA) monitoring through liquid biopsies represents another promising biomarker approach. Dr. Raez explains that ctDNA levels correlate with tumor presence and treatment response, potentially allowing for real-time treatment adjustments. Declining ctDNA levels may indicate successful immunotherapy treatment, while stable or increasing levels might suggest the need to add chemotherapy to the treatment regimen.
Moving Toward Precision Immunotherapy
The integration of these new biomarker approaches represents a crucial step toward more personalized immunotherapy strategies. "We need to tailor immunotherapy approaches better because we want something more cost effective and less toxic for patients," emphasizes Dr. Raez. This multi-biomarker approach could help overcome the current "one-size-fits-all" approach to immunotherapy, leading to more precise treatment selection and improved patient outcomes.