Lonsurf (TAS‑102) Nudges ctDNA Clearance to 36% and Extends DFS to 9.4 mo in MRD‑Positive CRC

Lonsurf (TAS‑102; trifluridine / tipiracil, a thymidine‑based nucleoside analog plus thymidine‑phosphorylase inhibitor), previously approved for mCRC, was given for six 28‑day cycles in the single‑arm, phase II INTERCEPT‑TT study (NCT05343013). Fifteen stage II‑IV colorectal cancer patients who remained ctDNA‑positive after curative surgery + adjuvant chemo received 35 mg/m² bid (days 1‑5, 8‑12). ctDNA cleared in 47% at 3 mo and 36% at 6 mo versus 6.7% in a matched synthetic‑control (SC) cohort under observation (P = .003 / .025). Median disease‑free survival reached 9.4 mo (TAS‑102) versus 5.75 mo in SC (P = .03). Grade 3‑4 hematologic toxicity was not detailed, but prior RECOURSE data show neutropenia in 38% and median PFS 2.0 mo in heavily pre‑treated metastatic CRC. Background studies suggest ctDNA‑positive patients on surveillance alone relapse rapidly, with 12‑mo DFS ≈ 47% despite standard adjuvant therapy.