Background/objective: Lapatinib is a potent HER1 and HER2 inhibitor. Gemcitabine-cisplatin (GC) is a standard chemotherapy regimen for advanced/metastatic bladder cancer. This phase I study examined the safety of lapatinib in combination with GC in patients with bladder cancer. The primary aim was to determine the maximum tolerated dose (MTD) of lapatinib in combination with GC.
Methods: A 3 + 3 dose escalation protocol was used with lapatinib at 750, 1,000 and then 1,250 mg. It was dosed daily with gemcitabine (1,000 mg/m2 on days 1, 8 and 15) and cisplatin (70 mg/m2 on day 2) every 28 days. In all, 18 patients with a median age of 63 years (range 50-77) were included; 3/6, 3/5 and 6/7 patients received lapatinib at 750, 1,000 and 1,250 mg, combined with GC, in cohorts 1, 2 and 3, respectively.
Results: No dose-limiting toxicities (DLTs) were observed in cohort 1 or 2 (3 patients each); in cohort 3 (2 × 3 patients), 1 of the 6 patients presented DLTs (grade 4, treatment-related febrile neutropenia and renal failure). Twelve patients received 6 cycles.
Conclusions: Lapatinib at 750-1,250 mg combined with GC appears safe and tolerable. The MTD of lapatinib combined with GC in bladder cancer was 1,250 mg.
© 2015 S. Karger AG, Basel.