Activity of oral irinotecan (IRI) in metastatic breast cancer (MBC) patients after prior anthracycline, taxane and capecitabine: Phase 2 study results

562 Background: Oral IRI offers patient (pt) convenience and provides protracted drug exposure. Following reported activity of IV IRI (Camptosar) in refractory MBC (Perez et al. JCO 22:2849), this study evaluates efficacy and safety of two oral IRI schedules in pts with MBC after failure of prior anthracycline(A), taxane(T), and capecitabine(C). Methods: Multicenter, 2-arm, randomized phase 2 study with Simon 2-stage design. Eligible pts have histologically confirmed, measurable MBC. Failure of prior A, T or C includes progression during or following treatment, lack of response after ≥ 4 cycles or significant treatment related toxicity. Pts are randomized to oral IRI Days 1–5 (Dx5) or Days 1–14 (Dx14) every 21 days at daily doses of 60 mg/m2 or 30 mg/m2, respectively. Results: Efficacy: 76 of 78 treated pts enrolled in Stage 1 were evaluable for response (Dx5:37 - Dx14:39). Median age is 57 (range 34–85); ECOG PS 0 (32%), 1 (61%), 2 (7%). Median number of prior regimens is 5. Oral IRI is active with confi...