A Phase I Study Of Aee788, A Multitargeted Inhibitor Of Erbb And Vegf Receptor Family Tyrosine Kinases, To Determine Safety, Pk And Pd In Patients (Pts) With Advanced Colorectal Cancer (Crc) And Liver Metastases

4065 Background: AEE788 (AEE) is an oral inhibitor with potent activity against EGFR, ErbB2, and KDR. This phase I study was to assess the safety, PK, PD, and MTD/DLT of AEE in pts with CRC and liver metastases. Methods: AEE was given PO at 25, 50, 100, 250, 300 or 400 mg/day daily in 28-day cycles (C) to 3–6 pt cohorts. 24-hr PK was obtained on C1, days (D)1, 15 and 28. PK parameters of AEE and active metabolite, AQM674 (AQM) were computed by non-compartmental methods. PD markers were analyzed in skin (SK), and tumor (TU) biopsies pre- and post-treatment. Samples were evaluated by both IHC and Laser Scanning Cytometry (LSC). DCE-MRI was performed at baseline (BL), and on C1D2 and 28 and C2D28. Results: 22 pts were treated at doses of 25 (n=4), 50 (n=3), 100 (n=4), 250 (n=1), 300 (n=4), and 400 mg (n=6). No DLT was reported. The most common AE (> 15%): fatigue (55%), vomiting (46%), diarrhea (41%), nausea (36%), dyspnoea (23%), constipation (18%) pyrexia (18%) and rash (18%). 2 pts had reversible gr 3/4 LFTs. Serum concentration of AEE and AQM increases with dose and dose duration. 7 pts had stable disease at the end of C2. Median time on treatment was 56 days (range 7–168). In SK, at doses =100 mg, pEGFR, pMAPK and Ki67 were inhibited by an average of 51, 54 and 41%, respectively by IHC. In endothelial cell (EC) pKDR/KDR was significantly inhibited (4-fold) in the wound-induced SK in a dose-dependent manner by LSC. In TU, inhibition of pEGFR, pMAPK and Ki67 at 400 mg was 100%, 90% and 39%, respectively by IHC. EC pKDR decreased with dose, however, trend was not significant. 1 out 15 pts who had BL and end of C1 DCE-MRI had > 40% Ktrans reduction. Conclusions: A dose dependent inhibition of pKDR, pEGFR, and pMAPK in skin and tumor was observed. However, no significant effects were observed on Ki67 and apoptosis in TU. No dose dependent reduction in Ktrans from DCE-MRI was observed. These findings were consistent with the lack of clinical activity of AEE up to 400 mg in this patient population. The study has been discontinued without reaching DLT due to safety data from other phase I studies and in favor of different dosing schedules. No significant financial relationships to disclose.