Results of the IDEA project, a prospective preplanned pooled analysis of 6 concurrently conducted randomised phase III trials, were presented at ASCO 2017.

ACHIEVE was one of the 6 trials which compared 3 months (3m) duration with 6 months (6m) duration of oxaliplatin-based adjuvant chemotherapy.

ACHIEVE was an open-label, multicenter trial randomising patients with stage III colon cancer to receive 3m or 6m of mFOLFOX6/CAPOX after surgery.

Choice of regimen was declared before randomisation by a site investigator.

Primary endpoint was disease-free survival (DFS).

Between August 2012 and June 2014, 1313 patients from Japan were randomised and, of those, 1291 patients were analysed for analysis.

Median age was 66 years; stage distribution was 15% T1-2, 57% T3, and 28% T4 and 26% N2; the highest proportion of patients with CAPOX (75%) among the 6 IDEA trials was included.

The frequency of grade 2 or higher neurotoxicity was significantly lower in arm 3m than in arm 6m (14% vs 36%, p<0.001), and the same held for that of grade 3 or higher neurotoxicity (1% vs 6%, p<0.001).

As of June 2017, a total of 291 (23%) DFS events were observed with a median follow-up of 39.0m.

Overall, the 3-year DFS rate was 79.5% for 3m and 77.9% for 6m, with a hazard ratio (HR) of 0.954 (95%CI, 0.758-1.201).

Subgroup analyses revealed that HR was 0.811 (0.532-1.236) for low risk (T1-3 and N1) and 1.066 (0.810-1.403) for high-risk (T4 or N2), whereas HR was 1.065 (0.709-1.600) and 0.904 (0.684-1.195) in patients with FOLFOX and CAPOX, respectively.

ACHIEVE was the only investigation in Asia among 6 trials and the results were placed into the context of the IDEA collaboration.

Short duration significantly decreased neurotoxicity.

It is notable that the efficacy results of overall analysis as well as those of subgroup analyses by risk group and study regimen in ACHIEVE were consistent with the results of IDEA. 

Source: ESMO