ReACT 1.0: HPV ctDNA-Guided Risk-Adapted Therapy

By Azon Vault On May 8, 2026

Introduction: Why HPV ctDNA matters

The presence of human papillomavirus (HPV) circulating tumor DNA (ctDNA) in the blood offers a non‑invasive way to monitor disease. In HPV‑positive oropharyngeal cancer, ctDNA can reveal tumor burden and guide therapy adjustments.

What is the ReACT 1.0 trial?

The ReACT 1.0 study is an exploratory phase II trial that uses HPV ctDNA to adapt treatment intensity for patients with HPV‑positive oropharyngeal cancer. The goal is to deliver the right therapy at the right dose while minimizing toxicity.

Study design

Enrolled 30–40 newly diagnosed HPV‑positive oropharyngeal cancer patients.
All participants provided baseline blood samples for ctDNA analysis.
Therapy intensity (radiation dose, chemotherapy regimen) is adjusted based on ctDNA levels at predefined time points.
Primary endpoint: feasibility and safety of ctDNA‑guided risk‑adapted therapy.
Secondary endpoints: progression‑free survival and quality‑of‑life outcomes.

How risk‑adapted therapy works

Risk‑adapted therapy means tailoring the treatment plan according to each patient’s biological risk profile. In this trial, ctDNA results classify patients into low, intermediate, or high risk, and the corresponding radiation or chemotherapy intensity is modified accordingly.

Key findings so far

Early data suggest that ctDNA‑guided adjustments lead to fewer unnecessary chemotherapy cycles and maintain excellent local control rates. Patients with undetectable ctDNA after treatment appear to have the lowest risk of recurrence.

Implications for patients and clinicians

For patients, this approach promises more personalized care with potentially fewer side effects. Clinicians gain a rapid, blood‑based biomarker that can inform decisions without waiting for imaging or invasive biopsies.

Conclusion

The ReACT 1.0 trial demonstrates the promise of HPV ctDNA‑guided risk‑adapted therapy in HPV‑positive oropharyngeal cancer. As the study progresses, it may set a new standard for personalized, biomarker‑driven treatment in head and neck oncology.