3505 Background: IMC-A12 is a fully human IgG1 monoclonal antibody directed against the human insulin like growth factor-I receptor. The safety and maximum tolerated dose (MTD) of IMC-A12 are being evaluated in an on-going a phase I trial. Methods: Patients (pts) with ECOG PS = 2 and advanced refractory solid tumors receive IMC-A12 weekly for 4 infusions per cycle until progression. After cycle one only, there is a two week observation period. Six cohorts of IMC-A12 are planned at 3, 6, 10, 15, 21, 27mg/kg. Sampling for PK and human anti-human antibodies directed against IMC-A12 occurs before and after the first and fourth doses of each cycle. Results: Fifteen pts have been treated, 7 at 3 mg/g, 4 at 6 mg/kg, 3 at 10 mg/kg and 1 at 15 mg/kg. Data is available for the first 11 pts: 7 male, 4 female, median age 56 years (range: 45–70). Treatment related toxicities for the first 11 pts include: grade 1 pruritis, rash, discolored feces; grade 2 anemia, psoriasis, hyperglycemia, infusion-related reaction; grade 3 hyperglycemia. Four of 11 pts have stable disease: 2 at the 3 mg/kg dose remain stable for >9 months (1 male breast cancer,1 hepatocellular cancer) and 2 at the 6 mg/kg dose (1 bladder, 1 endometrial) were stable after cycle 1. One pt with prostate cancer had >25% decline in PSA and stable radiographic disease at time of study discontinuation (week 5) for DLT. Non-compartmental PK analysis reveals a mean t1/2 of 148 and 209 hrs, mean Cmax of 333 and 415 ug/mL, and mean AUC0-Inf of 51317 and 80727 hr*ug/mL at the 3 and 6 mg/kg dose levels, respectively. Target trough levels have been achieved. Conclusions: Weekly administration of IMC-A12 appears to be well tolerated and the MTD has not been reached. The PK profile is consistent with that of other Mab’s. There is early evidence of clinical activity and correlative IGF biomarker data will be available. IMC-A12 will be further evaluated in prostate, breast, and other cancers. No significant financial relationships to disclose.
Phase I Dose Escalation Study of the Anti–Insulin-Like Growth Factor-I Receptor Monoclonal Antibody CP-751,871 in Patients with Refractory Solid Tumors