Alexander Marmé

Phase I Trial of the Trifunctional Anti-HER2 × Anti-CD3 Antibody Ertumaxomab in Metastatic Breast Cancer

Purpose: Ertumaxomab is an intact bispecific antibody targeting HER2/neu and CD3 with selective binding to activatory Fcγ type I/III receptors, resulting in the formation of a tri-cell complex between tumor cells, T cells, and accessory cells. Patients with metastatic breast cancer were enrolled into a multicenter phase I dose-escalating trial. Experimental Design: Three ascending doses of ertumaxomab (10-200 μg) were administered i.v. on day 1, 7 ± 1, and 13 ± 1. Safety and tolerability were the primary objectives. Secondary objectives were antitumor activity and different immunologic variables. Results: Fifteen out of 17 enrolled patients completed the study. One hundred micrograms was identified as the maximal tolerable single dose. Most drug-related adverse events were mild and transient including fever (94%), rigors (47%), headache (35%), nausea (29%), vomiting (29%). Grades 3 and 4 (Common Toxicity Criteria) were lymphocytopenia (76%) and elevation of liver enzymes (47%). One patient (200 μg dose) developed severe hypotension and respiratory distress syndrome, another patient (150 μg dose) developed a systemic inflammatory response syndrome and acute renal failure. Aggravation of congestive heart failure was seen in one patient with preexisting ventricular dysfunction after administration of the third dose (200 μg). All adverse events were fully reversible. Antitumor response was seen in 5 out of 15 evaluable patients (one with a complete response, two with partial responses, two with stable disease) at dose levels of ≥100 μg. Measurements of cytokines (interleukin-6, interleukin-2, tumor necrosis factor-α, and IFN-γ) suggest a strong T helper cell type 1–associated immune response. The induction of human anti-mouse/anti-rat antibodies was detected in 5 out of 16 (31%) patients. Discussion: Treatment with triple infusions of ertumaxomab yields a strong immunologic response. Doses up to 100 μg can be safely infused with close monitoring of patients. The observed clinical responses are encouraging and indicate antitumor efficacy.

Cleavage of L1 in Exosomes and Apoptotic Membrane Vesicles Released from Ovarian Carcinoma Cells

Purpose: The L1 adhesion molecule (CD171) is overexpressed in human ovarian and endometrial carcinomas and is associated with bad prognosis. Although expressed as a transmembrane molecule, L1 is released from carcinoma cells in a soluble form. Soluble L1 is present in serum and ascites of ovarian carcinoma patients. We investigated the mode of L1 cleavage and the function of soluble L1. Experimental Design: We used ovarian carcinoma cell lines and ascites from ovarian carcinoma patients to analyze soluble L1 and L1 cleavage by Western blot analysis and ELISA. Results: We find that in ovarian carcinoma cells the constitutive cleavage of L1 proceeds in secretory vesicles. We show that apoptotic stimuli like C2-ceramide, staurosporine, UV irradiation, and hypoxic conditions enhance L1-vesicle release resulting in elevated levels of soluble L1. Constitutive cleavage of L1 is mediated by a disintegrin and metalloproteinase 10, but under apoptotic conditions multiple metalloproteinases are involved. L1 cleavage occurs in two types of vesicles with distinct density features: constitutively released vesicles with similarity to exosomes and apoptotic vesicles. Both types of L1-containing vesicles are present in the ascites fluids of ovarian carcinoma patients. Soluble L1 from ascites is a potent inducer of cell migration and can trigger extracellular signal-regulated kinase phosphorylation. Conclusions: We suggest that tumor-derived vesicles may be an important source for soluble L1 that could regulate tumor cell function in an autocrine/paracrine fashion.

Clinical and mechanistic aspects of glucocorticoid-induced chemotherapy resistance in the majority of solid tumors

Background: Glucocorticoids have been used widely in conjunction with cancer therapy due to their ability to induce apoptosis in hematological cells and to prevent nausea and emesis. However, recent data including ours, suggest induction of therapy-resistance by glucocorticoids in solid tumors, although it is unclear whether this happens only in few carcinomas or is a more common cell type specific phenomenon. Material and Methods: We performed an overall statistical analysis of our new and recent data obtained with 157 tumor probes evaluated in vitro, ex vivo and in vivo. The effect of glucocorticoids on apoptosis, viability and cell cycle progression under diverse clinically important questions was examined. Results: New in vivo results demonstrate glucocorticoid-induced chemotherapy resistance in xenografted prostate cancer. In an overall statistical analysis we found glucocorticoid-induced resistance in 89% of 157 analysed tumor samples. Resistance is common for several cytotoxic treatments and for several glucocorticoid-derivatives and due to an inhibition of apoptosis, promotion of viability and cell cycle progression. Resistance occurred at clinically achievable peak plasma levels of patients under anti-emetic glucocorticoid therapy and below, lasted for a long time, after one single dose, but was reversible upon removal of glucocorticoids. Two non-steroidal alternative anti-emetic agents did not counteract anticancer treatment and may be sufficient to replace glucocorticoids in co-treatment of carcinoma patients. Conclusion: These data demonstrate the need for prospective clinical studies as well as for detailed mechanistic studies of GC-induced cell-type specific pro- and anti-apoptotic signaling.

Preeclampsia : increased expression of soluble ADAM 12

Preeclampsia is a multisystemic pregnancy-associated disease affecting about 3–7% of pregnancies worldwide and is still a principal cause of fetal and maternal morbidity and mortality. To identify potential markers, we have compared gene expression profiles from control and preeclamptic placental tissues taken at various age-matched gestational stages using complementary DNA microarray analysis. Besides previously identified preeclampsia-associated genes, novel differentially expressed transcripts were found. The soluble form of the disintegrin metalloprotease ADAM 12 (a disintegrin and metalloproteinase 12; meltrin-α) represented the most upregulated transcript. This was confirmed by in situ hybridization of sections of preeclamptic placentas and by serum protein analysis of preeclamptic pregnant women. Thus, ADAM 12 could serve as an early biomarker for preeclampsia that may be of predictive and/or functional significance.

Loss of Drop1 expression already at early tumor stages in a wide range of human carcinomas.

In a study on gene deregulation in ovarian carcinoma we found a mRNA coding for a 350 kDa protein, Drop1, to be downregulated 20‐ to 180‐fold in the majority of ovarian and mammary carcinomas. The mRNA is encoded by a set of exons in the 5′ region of the SYNE1 gene. Immunohistochemical staining for Drop1 protein by a specific monoclonal antibody corresponds to the pattern seen for the mRNA. cDNA arrays of matched pairs of tumor and normal tissue and in situ hybridizations confirmed the drastic loss of Drop1 mRNA as a common feature in uterus, cervix, kidney, lung, thyroid and pancreas carcinomas, already at early tumor stages and in all metastases. Two‐hybrid studies suggest a role of this deficiency in the malignant progression of epithelial tumors.

Pre-existing T-cell immunity against mucin-1 in breast cancer patients and healthy volunteers

Purpose: There is evidence that some tumor patients are able to generate tumor-associated antigen (TAA)-specific T-cell immunity spontaneously. However, little is understood about the existence and nature of self-reactive T-cells that recognize TAA in healthy donors (HD). Methods: Human mucin (MUC-1), a highly glycosylated transmembrane protein, is a well characterized TAA expressed by epithelial tumors. We compared endogenous MUC-1-specific T-cell immunity of breast cancer patients (BCP) and healthy volunteers using two MUC-1-derived HLA-A*0201-restricted peptides (MUC-1950–958, MUC-112–20). Antigen-dependent interferon (IFN)-γ and Granzyme B expression of T-cells were analysed by a reverse transcription-polymerase chain reaction (qRT-PCR)-based assay. Results: A 32% of BCP and 43% of healthy volunteers revealed pre-existent CD8+ T-cells specific for MUC-1950–958 but not for MUC-112–20. In patients, MUC-1-specific T-cells have been detected mainly in early stage disease prior adjuvant therapy. Those T-cells showed MUC-1-dependent IFN-γ production after short-term stimulation but no clear Granzyme B expression. However, after repetitive in vitro stimulations using peptide-pulsed CD40-stimulated B-cell lines as autologous antigen presenting cells (APC) T-cell lines exhibited lytic capacity against HLA-A*0201+/MUC-1+ tumor cells. Conclusion: MUC-1950–958 is a dominant tumor antigen against which CD8+ T-cells were found frequently in BCP as well as in HD. Until now, this was only known for MelanA/MART-1. In contrast to previous reports, MUC-1-specific immunity was not linked to gender or number of pregnancies in women. Whether MUC-1950–958-related immunity highlights a yet unknown cross-reactivity in HD remains unclear. The presence of MUC-1-specific T-cells in some BCP may reflect a balance between immune tolerance and immune defence during aetiopathology.

Efficient carcinoma cell killing by activated polymorphonuclear neutrophils targeted with an Ep-CAM×CD64 (HEA125×197) bispecific antibody

Abstract. Bispecific antibodies (bsAb) have attracted much attention over the past several years as a mean to improve immunotherapy of cancer. Due to their dual specificity, bsAb are able to redirect effector cells against tumor targets. In this study, the development and preclinical testing of a new quadroma-derived bsAb, HEA125×197, recognizing the tumor-associated Ep-CAM antigen and the high affinity Fc receptor for IgG, CD64, is reported. Using granulocyte-colony stimulating factor (G-CSF) and interferon-gamma (IFN-γ)-stimulated polymorphonuclear neutrophils to induce CD64 expression, bsAb HEA125×197 elicited strong cytotoxic activity towards allogeneic and autologous ovarian carcinoma cells. The cytolytic efficiency of this antibody was comparable to that of a previously described bsAb, HEA125×OKT3, targeting preactivated T lymphocytes against Ep-CAM-carrying tumor cells. Based on the pan-carcinoma specificity and the stable expression of Ep-CAM, bsAb HEA125×197 may broaden the spectrum of bispecific reagents for the treatment of epithelial malignancies.

Glucocorticoids and progression of breast cancer.

Commentary to: Avoiding Glucocorticoid Administration in a Neurooncological Case Hans Peter Rutz, Silvia Hofer, Pietro E. Peghini, Ursula Gutteck-Amsler, Katharina Rentsch, Peter J. Meier-Abt, Urs R. Meier and René Ludwig Bernays Cancer Biology & Therapy; Volume 4, Issue 11 http://www.landesbioscience.com/journals/cbt/abstract.php?id=2232