PURPOSE This study reports a phase I immunotherapy (IT) trial in 23 women with metastatic breast cancer consisting of eight infusions of anti-CD3 × anti-HER2 bispecific antibody (HER2Bi) armed anti-CD3 activated T cells (ATC) in combination with low dose interleukin 2 (IL-2) and granulocyte-macrophage-colony stimulating factor to determine safety, maximum tolerated dose (MTD), technical feasibility, T cell trafficking, immune responses, time to progression, and overall survival (OS). EXPERIMENTAL DESIGN ATC were expanded from leukapheresis product using IL-2 and anti-CD3 monoclonal antibody and armed with HER2Bi. In 3+3 dose escalation design, groups of 3 patients received 5, 10, 20, or 40 × 109 armed ATC (aATC) per infusion. RESULTS There were no dose limiting toxicities and the MTD was not defined. It was technically feasible to grow 160 × 109 ATC from a single leukapheresis. aATC persisted in the blood for weeks and trafficked to tumors. Infusions of aATC induced anti-breast cancer responses and increases in immunokines. At 14.5 weeks after enrollment, 13 of 22 (59.1%) evaluable patients had stable disease and 9 of 22 (40.9%) had progressive disease. The median OS was 36.2 months for all patients, 57.4 months for HER2 3+ patients, and 27.4 months for HER2 0–2+ patients. CONCLUSIONS Targeting HER2 positive and negative tumors with aATC infusions induced anti-tumor responses, increases in Th1 cytokines and IL-12 serum levels that suggest that aATC infusions vaccinated patients against their own tumors. These results provide a strong rationale for conducting phase II trials.

IL-4 and IL-13 are related cytokines which induce both pro-and anti-in¯ammatory e ects depending on the cell type they act upon and the nature of the receptors expressed. The type I receptor complex is composed of the IL-4Ra and gc and only binds IL-4, whereas, in the type II receptor, IL-4Ra dimerizes with IL-13Ra1 upon either IL-4 or IL-13 binding. Another ligand binding chain potentially implicated in the IL-4/IL-13 receptor has been described, the IL-13Ra2, but the regulation of its expression and its role in IL-4/IL-13 transduction is poorly understood. In this study we report that IL-4 and IL-13 upregulate IL-13Ra2 at both the mRNA and protein levels in the keratinocyte cell line HaCaT. In these cells, IL-4 or IL-13 were shown to activate the Janus Kinases JAK1 and JAK2, the transcription factor STAT6, and the ERK and p38 mitogen-activated protein kinases. We show that IL-4 or IL-13-induced IL-13Ra2 mRNA expression was inhibited by the ERK inhibitor U0126, the JAK inhibitor AG490 and, to a lesser extent, the p38 MAPK inhibitor SB203580. Moreover, expression of a constitutive active mutant of STAT6 alone did not modify IL-13Ra2 mRNA expression, but potentiated the e ects of IL-4 or IL-13 on IL-13Ra2 expression. The constitutive active mutants of MEK1 or MKK6 increased the level of expression of IL-13Ra2 mRNA even in absence of stimulation. Our ®ndings demonstrate, for the ®rst time, that IL-4 and IL-13 can induce IL-13Ra2 expression in keratinocytes, and that the ERK and p38 MAPK together with JAK2 and STAT6 play a critical role in this process. Oncogene (2001) 20, 6660 ± 6668.