3076 Background: HM781-36B is a pan-HER tyrosine kinase inhibitor, which showed a potent activity against the gefitinib- or erlotinib-resistant, EGFR L858R/T790M double mutant cells. A phase I study was conducted to determine the MTD, pharmacokinetics, and antitumor activity. Methods: Eligible pts had advanced malignancies refractory to standard therapies. Standard 3+3 scheme was used in the dose escalation part, and additional 12 pts were enrolled in the expansion cohort of molecular enrichment. Results: In dose-escalation part, 43 pts (median age: 55 yrs (range 25-82), M:F=25:18, ECOG PS 0/1/2/3: 23/17/2/1, median prior chemotherapy: 4) were treated. DLTs were G3 diarrheas in 5 pts, one at 12 mg, 16 mg, 24 mg, and two at 32 mg. The MTD was determined as 24mg. The most common drug-related adverse events were diarrhea, stomatitis, rash, pruritus, and anorexia. Among 41 evaluable pts, 4 pts achieved PR (1 unconfirmed, duration of response: 11.9 mo, 7.07 mo+, 4.5 mo+), and 19 pts had SD. Two of 4 PR pts were Her2-positive breast cancer pts. The median duration of treatment in pts with PR or SD was 3.87 (2.47- 15.17) months. In the dose range of 0.5 to 24 mg, it showed linear pharmacokinetics proportional to dose-escalation, relatively short half-life, and little accumulation. Additional 12 pts in the expansion cohort are under treatment at 24 mg (6 pts: EGFR-mutant NSCLC, 3 pts: Her2-positive gastric cancer, 2 pts: Her2-positive breast cancer, 1 pt: rectal cancer). Conclusions: HM781-36B was safe and well tolerable in advanced solid tumors. Preliminary evidence of anticancer activity has been observed. Updated data will be presented at the meeting.
Phase I Study of Intermittent High-Dose Lapatinib Alternating with Capecitabine for HER2-Positive Breast Cancer Patients with Central Nervous System Metastases