Risk-adaptive therapy guided by dynamic ctDNA in nasopharyngeal carcinoma.

Despite promising data showing that circulating tumour DNA (ctDNA) dynamics during treatment can inform real-time tumour response and recurrence risk1, how best to translate these insights into actionable clinical decision-making remains unclear. Here we report results from the EP-STAR trial-a multi-centre, ctDNA-driven, risk-adapted, non-randomized phase II study ( NCT04072107 ; ClinicalTrials.gov) testing whether a risk-adaptive treatment (RAT) strategy guided by on-treatment ctDNA dynamics can meaningfully improve survival, using nasopharyngeal carcinoma as a model. Eligible patients were enrolled and began treatment with standard-of-care gemcitabine-cisplatin neoadjuvant chemotherapy (GP-NAC; the P in this abbreviation stands for platinum)2, followed by RAT or standard-of-care chemoradiotherapy guided by ctDNA clearance trajectory during GP-NAC. Protocol-eligible patients who did not receive RAT, drawn from a prospectively registered ctDNA biomarker cohort ( NCT03855020 )3, served as a non-randomized, contemporaneous no-RAT external cohort. The primary end-point was failure-free survival (FFS) in the RAT group. After a median follow-up of 47.3 months, the 3-year FFS was 89.1% (83.2-95.0%) in the RAT group (n = 110). Patients who received RAT showed significantly improved FFS (P = 0.003, log-rank test) compared with the no-RAT external cohort (hazard ratio = 0.41 [0.23-0.75]; P = 0.004, Cox regression model). The RAT strategy was well-tolerated with no treatment-related deaths. Collectively, these data show that a ctDNA-driven RAT paradigm could be a promising strategy to improve survival, challenging the conventional fixed-course, static treatment approach.