Final OS analyses comparing trifluridine/tipiracil + bevacizumab versus capecitabine + bevacizumab in first-line unresectable mCRC patients noneligible for intensive therapy

Presented by

Prof. Eric Van Cutsem, KU Leuven, Belgium

Conference

ASCO GI 2021

Trial

Phase 2, TASCO1

Patients with unresectable metastatic colorectal cancer (mCRC) not eligible for standard intensive chemotherapy randomly received treatment with trifluridine/tipiracil and bevacizumab or capecitabine and bevacizumab. Patients treated with the first combination showed a 4.64 months longer median overall survival (OS).

Prof. Eric Van Cutsem (KU Leuven, Belgium) presented the final end-of-study OS analysis of the phase 2 randomised study TASCO1 (NCT02743221) in patients with unresectable mCRC [1]. The results of the primary study analysis were reported earlier and demonstrated a promising efficacy in terms of progression-free survival (PFS) and an acceptable safety profile for the combination of trifluridine/tipiracil + bevacizumab [2].

Previously untreated patients not eligible to receive standard oxaliplatin- or irinotecan-based chemotherapy regimens were enrolled into 2 study arms to receive either trifluridine/tipiracil administered orally at 35 mg/m²/dose twice daily from days 1-5 and days 8-12, and bevacizumab at 5 mg/kg on days 1 and 15 of a 28-day treatment cycle (TT-B; n=77), or capecitabine administered orally at 1,250 or 1,000 mg/m²/dose twice daily (according to the patient’s status) from days 1-14 and bevacizumab at 7.5 mg/kg on day 1 of a 21-day treatment cycle (C-B; n=76). Cycles were repeated until documented disease progression, unacceptable toxicity, or investigator’s/patient’s decision. Following treatment discontinuation, all patients were followed for OS until the end-of-study, i.e. the date of the withdrawal visit for the last patient.

Of the 153 patients randomised and followed until end-of-study, 21 were alive (11 in TT-B, 10 in C-B arm) and censored for the analysis. Median OS was 22.31 months in TT-B and 17.67 months in C-B (HR 0.78; 95% CI 0.55-1.10; see Figure). Survival probability at 18 months in TT-B was 0.62 versus 0.47 in C-B.

Figure: Overall survival in TASCO1 trial [1]

The safety profiles of both study arms remained unchanged from the initial analysis [2], with a generally good tolerance in patients treated with TT-B.

In summary, in line with the earlier published PFS, the OS analyses shows promise for TT-B in patients with previously untreated unresectable mCRC ineligible for standard combination chemotherapy. The final study analysis provided further evidence for TT-B as a noteworthy valuable regimen in this population settings. There is an ongoing randomised phase 3 study (SOLSTICE, NCT03869892) to confirm these results.

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