Selective TACE with irinotecan-loaded 40 μm microspheres and FOLFIRI for colorectal liver metastases: phase I dose escalation pharmacokinetic study.

BACKGROUND

Efficacy of treatments for colorectal liver metastases after failure of first-line chemotherapy is limited. The aim of this study was to prospectively evaluate the feasibility, tolerability, and pharmacokinetics of selective transarterial chemoembolization (TACE) with irinotecan-loaded 40 μm microspheres combined with systemic FOLFIRI for colorectal liver metastases refractory to oxaliplatin regimen.

METHODS

The dose escalation study was conducted in three patient groups with different amounts of irinotecan loaded (50, 75 and 100 mg per mL-microspheres). Selective catheterization was performed to embolize subsegments or segments of located tumors using TACE navigation system. FOLFIRI was administrated 7 days after TACE. Plasma concentration was measured before and time points after administration.

RESULTS

Nine patients successfully underwent a total of 22 TACE procedures. Dose-limiting toxicity did not appear at any level. The overall response rate was 55.6%. The median progression free and overall survival were 8.1 and 18.2 months, respectively. The AUC and C of plasma SN-38 per 1 mg injected irinotecan dose were significantly higher in irinotecan-loaded microspheres compared with FOLFIRI (P = 0.009 and P <  0.001, respectively).

CONCLUSION

Selective TACE using 40 μm irinotecan-loaded microspheres combined with systemic FOLFIRI was feasible and safe even when a high dose of irinotecan was loaded. Irinotecan-loaded microspheres resulted in a higher plasma concentration and AUC of SN-38 than treatment with FOLFIRI. Further large scale trials to evaluate the efficacy are mandatory.

TRIAL REGISTRATION

University Hospital Medical Information Network (UMIN) Clinical Trials Registry, Registration number; UMIN000015367 ; Registered date; 08,10,2014.