Phase I safety and tolerability of once daily oral afatinib (A) in combination with gemcitabine (G) in patients with advanced solid tumors.

Abstract

e13009 Background: A is an orally bioavailable, irreversible, ErbB Family Blocker. This open label, Phase I, dose escalation trial investigated the safety, tolerability and pharmacokinetics of A in two parallel dose cohort expansion parts, in combination with either G (Part A) or docetaxel (Part B) in patients with relapsed or refractory solid tumors. Preliminary results from Part A are presented here. Methods: Eligible patients (confirmed diagnosis of advanced solid tumors, ECOG PS 0–1) received once-daily, oral dosing of A in combination with G, given intravenously at Day 1 and at Day 8 of every 3 week cycle. Dosing of A started on Day 2 of Cycle 1. The primary objective was to establish the maximum tolerated dose (MTD) based on the occurrence of dose limiting toxicities (DLTs) observed in Cycle 1. Dose escalation was performed with cohorts of 3–6 patients using a 3+3 design. Initial starting dose level was A 30 mg/day and G 1000mg /m², escalating up to A 50 mg/day and G 1250 mg/m², until the MTD was reached, and followed by a PK expansion cohort of 12 patients at the MTD level. Incidence and severity of AEs were recorded. Results: To date, 19 patients have been treated on study with the following baseline characteristics: mean age (53.7 years), women (63.2%) and number of prior chemotherapies (≤2: 26%, >2: 74%). Twelve patients received 2–4 cycles of treatment and five patients received 4 or more cycles. AEs observed in most patients were diarrhea (89.5%) and rash (63.2%). In Cycle 1, DLTs were experienced by one patient out of six receiving A 30 mg and G 1250 mg/m². MTD was exceeded at a dose level of at least A 40 mg/day and G 1250 mg/m². An intermediate dose level of A 40 mg/day and G 1000 mg/m² is currently under evaluation. Conclusions: In patients with relapsed or refractory advanced solid tumors, the combination of A with G is well tolerated, with manageable AEs. Dose finding is ongoing and MTD, safety profile and preliminary evidence of activity are anticipated to be reported at time of presentation.