Phase I safety and tolerability of once daily oral afatinib (A) in combination with docetaxel (D) in patients (pts) with relapsed or refractory advanced solid tumors.

Abstract

e13010 Background: A is an orally bioavailable, irreversible, ErbB Family Blocker. This open label, Phase I, dose escalation trial investigated the safety, tolerability, and PK of A, in two parallel dose cohort expansion parts, in combination with either gemcitabine (Part A) or D (Part B) in patients with relapsed or refractory solid tumors. Preliminary results from Part B are presented here. Methods: Eligible pts (confirmed diagnosis of advanced solid tumors, ECOG PS 0–1) received once daily, oral dosing of A in combination with D, given iv on Day 1 of every 3 week cycle. Dosing of A started on Day 2 of Cycle 1. Primary objective was to establish the maximum tolerated dose (MTD) based on the occurrence of dose limiting toxicities (DLT) observed in Cycle 1. Dose escalation was performed with cohorts of 3–6 pts using a 3+3 design. Initial starting dose level was A 30 mg/day and D 60 mg /m², escalating up to A 50 mg/day and D 75 mg/m² until the MTD was reached, and followed by a PK expansion cohort of 12 pts at the MTD level. Incidence and severity of AEs were recorded. Results: To date, 21 pts have been treated with A (30–50 mg/day) and D (60–75 mg/m2), with baseline characteristics: mean age (55.4 years), women (42.9%) and number of prior chemotherapies (≤2: 57%; >2: 43%). Fourteen pts received 2–4 cycles of treatment and five patients received 4 or more cycles. In Cycle 1, DLT was experienced by one out of six pts receiving 30 mg afatinib + 60 mg/m² docetaxel (Grade 3 diarrhea). No DLT was observed during the subsequent dose levels up to A 50 mg/day and D 75 mg/m². AEs observed in most pts were diarrhea (76.2%) and asthenia (66.7%). Conclusions: In pts with relapsed or refractory advanced solid tumors, the combination of A and D is well tolerated. AEs were manageable and the MTD was not reached in the tested dose range up to A 50 mg/day and D 75 mg/m². Considering the potential for diarrhea and rash during later cycles, the recommended dose for the expansion cohort was A 40 mg/day in combination with D 75 mg/m². Enrollment is ongoing (nine pts to date) and additional safety data and preliminary evidence of activity are anticipated to be available at the time of presentation.