ideasIdea
ctDNA-guided adjuvant therapy in stage II-III melanoma
Most stage II patients never relapse, yet all are offered a year of immunotherapy. Use a blood test to treat only those with detectable residual disease.
KEYNOTE-716 and CheckMate 76K treat everyone in stage IIB/IIC for a modest absolute benefit. Tumour-informed ctDNA assays could identify the minority at risk. The DETECTION trial (UK) tests this approach.
Hypothesis
Reserving adjuvant PD-1 for ctDNA-positive patients (or starting at ctDNA conversion) achieves equivalent distant metastasis-free survival with far fewer patients treated.
Rationale
Melanoma sheds ctDNA proportional to burden; IMvigor011 proved the concept in bladder cancer; over-treatment and immune toxicity in stage II are substantial.
What would test it
Randomised trial of ctDNA-triggered versus standard adjuvant pembrolizumab in stage IIB-IIIA with DMFS endpoint (the DETECTION design).
Maturity
early clinical