Changes in circulating tumor DNA (ctDNA) levels are strongly associated with treatment outcomes across a range of solid tumor types, according to new data published this week in Clinical Cancer Research.

The results come from the ctMoniTR Project, a multi-phase initiative led by Friends of Cancer Research (Friends), designed to determine whether ctDNA can reliably predict how patients respond to cancer therapies.

The analysis, supported by Biodesix and Bio-Rad Laboratories, marks a critical step toward integrating ctDNA testing into standard therapeutic development pipelines and clinical decision-making. The study analyzed ctDNA dynamics across eight clinical trials involving patients with advanced non-small cell lung cancer (aNSCLC), broadening the scope to include multiple solid tumors and treatment modalities.

A powerful biomarker for response and survival

The newly published data builds on previous ctMoniTR findings—initially published in the Journal of Clinical Oncology—which identified a strong correlation between ctDNA level changes and overall survival in aNSCLC patients treated with immune checkpoint inhibitors. The second phase expands these findings, showing similar associations across other tumor types and with treatments such as tyrosine kinase inhibitors.

“ctDNA isn’t just a promising biomarker—it’s fast becoming essential to how we understand and measure therapeutic efficacy,” said Gary Pestano, chief development officer at Biodesix.

“We’re proud to support ctMoniTR as part of our mission to evolve the science of diagnostics and improve patient outcomes.”

Biodesix contributed data generated using Bio-Rad’s Droplet Digital PCR (ddPCR) platform, a highly sensitive method for detecting and quantifying ctDNA in blood samples. The collaboration underscores the power of industry-academic partnerships in accelerating translational research.

Looking ahead to clinical application and MRD detection

“Droplet Digital PCR is uniquely suited for this kind of work,” added Steve Kulisch, vice president of product management at Bio-Rad’s Digital Biology Group.

“We’re excited to see it play a role in efforts to standardize molecular residual disease (MRD) monitoring and advance precision oncology.”

Beyond the ctMoniTR Project, Biodesix is integrating ctDNA testing into its Development Services portfolio and is also exploring its combination with proteomics to enhance MRD detection. These advancements will be featured during the American Association for Cancer Research (AACR) Annual Meeting, taking place on Monday (April 28).

As researchers continue to validate ctDNA’s predictive value across cancer types and treatments, its role in clinical care is expected to grow—paving the way for more personalized, data-driven approaches to cancer therapy.