Phase I study to evaluate the safety and to assess the food effect of HM781-36B, a novel pan-HER inhibitor continuously given in patients with advanced solid tumors.

Abstract

2565 Background: HM781-36B, a novel pan-HER tyrosine kinase inhibitor, showed potent in vitro and in vivo antitumor activities for EGFR mutant models including T790M mutation. In the previous 2-weeks on, 1-week off phase I study, the maximum tolerated dose (MTD) was determined as 24 mg/day. Phase I study with a continuous daily dosing schedule was conducted to determine the recommended dose (RD), and to assess the effect of food on pharmacokinetics (PK) in patients (pts) with advanced solid tumors. Methods: Eligible pts had advanced malignancies refractory to standard therapies. Standard 3+3 scheme was used in the dose escalation study, and additional 8 patients were enrolled to test food effects. Results: 20 pts (median age: 55 years [range32-77], M:F=13:7, ECOG PS 0/1/2/3 8/12/0/0) were enrolled (5 NSCLC, 4 colon cancer, 3 stomach cancer, 2 breast cancer, 2 rectal cancer, 2 common bile duct cancer, 1 pancreatic cancer and 1 esophageal cancer); 12 in the dose escalation and 8 in the food effect study cohort. Twelve pts were heavily pretreated(≥4 regimens). Dose limiting toxicities (DLTs) were G3 anorexia in 1 pt at 18mg/day, G3 diarrhea and anorexia in 1 pt, and drug compliance <80% due to G2 adverse events in 1 pt at 24mg/day. The MTD was determined as 18 mg/day, and RD was determined as 16 mg/day. The most common drug-related adverse events were diarrhea, stomatitis, skin rash, paronychia, pruritus and anorexia. Among 16 evaluable pts, 4 achieved partial responses (PR)[1 NSCLC, 2 breast cancer, 1 common bile duct cancer], and the duration of response were 32, 40+, 21, and 8 weeks, respectively. Five pts had stable disease (SD). The median duration of treatment in pts with PR or SD was 33.5 weeks (range, 15-82). Under both fasted and fed condition, there were no significant differences of AUClast values, whereas Cmax values were lower in fed condition than in fasted condition. Conclusions: Continuous daily dosing schedule of HM781-36B is safe and well tolerated in advanced solid tumors. It exerts anticancer activity, without being influenced by food. Updated data will be presented at the meeting. Clinical trial information: NCT01455584.