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Predictive factors for severe toxicity of sunitinib in unselected patients with advanced renal cell cancer

Sunitinib has been registered for the treatment of advanced renal cell cancer (RCC). As patient inclusion was highly selective in previous studies, experience with sunitinib in general oncological practice remains to be reported. We determined the efficacy and safety of sunitinib in patients with advanced RCC included in an expanded access programme. ECOG performance status >1, histology other than clear cell and presence of brain metastases were no exclusion criteria. Eighty-two patients were treated: 23% reached a partial response, 50% had stable disease, 20% progressed and six patients were not evaluable. Median progression-free survival (PFS) was 9 months and median overall survival (OS) was 15 months. Importantly, 47 patients (57%) needed a dose reduction, 35 (43%) because of treatment-related adverse events, 10 (12%) because of continuous dosing, and two because of both. Stomatitis, fatigue, hand–foot syndrome and a combination of grade 1–2 adverse events were the most frequent reasons for dose reduction. In 40 patients (49%), there was severe toxicity, defined as dose reduction or permanent discontinuation, which was highly correlated with low body surface area, high age and female gender. On the basis of age and gender, a model was developed that could predict the probability of severe toxicity.

The role of initial immunotherapy as selection for nephrectomy in patients with metastatic renal cell carcinoma and the primary tumor in situ.

OBJECTIVE A prospective pilot study in patients with metastatic renal cell cancer and the primary in situ to assess the feasibility of immunotherapy prior to nephrectomy and to evaluate the rationale for a future randomized trial to define the role of response to upfront immunotherapy as selection for cytoreductive surgery. PATIENTS AND METHODS Sixteen patients with synchronous multiple metastases were treated with the primary tumor in place and were evaluated with regard to age, sex, sites of extrarenal disease, morbidity, response, nephrectomy rate, time to progression and overall survival. Immunotherapy consisted of 2 courses low-dose IL-2 4MIU/m(2), subcutaneous GM-CSF 2.5 microg/kg and interferon-alpha (IFN-alpha) 5MU flat on day 1-13 and 22-34. Patients with either partial remission (PR) or stable disease (SD) underwent nephrectomy followed by a third and fourth course. RESULTS No response was seen in the primary tumors. With regard to extrarenal sites SD was noted in nine cases, PR in two and progressive disease (PD) in five. Eleven patients underwent nephrectomy. No surgical complete response (CR) could be achieved. All patients with PD died after a median overall survival of 3 months versus 11.5 months (range 4-22) in those who underwent nephrectomy. Four patients are still alive at 10, 12, 18 and 19 months. Median duration of response was 6 months (range 2-10). One patient with SD following nephrectomy developed CR after two additional cycles, which is currently maintained for >10 months. CONCLUSIONS Absence of progression at metastatic sites following immunotherapy may be used as a selection for nephrectomy in this selected group. Non-responding patients can be spared from surgery. A randomized study is needed to assess the timing of nephrectomy in combination with immunotherapy with regard to morbidity, overall survival and quality of life.

Temozolomide followed by combined immunotherapy with GM-CSF, low-dose IL2 and IFN alpha in patients with metastatic melanoma.

The purpose of this study is to determine the toxicity and efficacy of temozolomide (TMZ) p.o. followed by subcutaneous (s.c.) low-dose interleukin-2 (IL2), granulocyte–monocyte colony stimulating factor (GM-CSF) and interferon-α 2b (IFNα) in patients with metastatic melanoma. A total of 74 evaluable patients received, in four separate cohorts, escalating doses of TMZ (150–250 mg m−2) for 5 days followed by s.c. IL2 (4 MIU m−2), GM-CSF (2.5 μg kg−1) and IFNα (5 MIU flat) for 12 days. A second identical treatment was scheduled on day 22 and cycles were repeated in stable or responding patients following evaluation. Data were analysed after a median follow-up of 20 months (12–30 months). The overall objective response rate was 31% (23 out of 74; confidence limits 20.8–42.9%) with 5% CR. Responses occurred in all disease sites including the central nervous system (CNS). Of the 36 patients with responding or stable disease, none developed CNS metastasis as the first or concurrent site of progressive disease. Median survival was 252 days (8.3 months), 1 year survival 41%. Thrombocytopenia was the primary toxicity of TMZ and was dose- and patient-dependent. Lymphocytopenia (grade 3–4 CTC) occurred in 48.5% (34 out of 70) fully monitored patients following TMZ and was present after immunotherapy in two patients. The main toxicity of combined immunotherapy was the flu-like syndrome (grade 3) and transient liver function disturbances (grade 2 in 20, grade 3 in 15 patients). TMZ p.o. followed by s.c. combined immunotherapy demonstrates efficacy in patients with stage IV melanoma and is associated with toxicity that is manageable on an outpatient basis.

Immunotherapy with concurrent subcutaneous GM-CSF, low-dose IL-2 and IFN-alpha in patients with progressive metastatic renal cell carcinoma.

The purpose of the study was to determine toxicity, efficacy and immunologic effects of concurrent subcutaneous injections of low-dose interleukin-2 (LD-IL-2), granulocyte–monocyte colony-stimulating factor (GM-CSF) and interferon-α 2b (IFNα) in progressive metastatic renal cell carcinoma. In a multicentre phase II study, 59 evaluable patients received two to six cycles of subcutaneous IL-2 (4 mIU m−2), GM-CSF (2.5 μg kg−1) and IFNα (5 mIU flat−1) for 12 days per 3 weeks with evaluation after every two cycles. Cycles were repeated in responding or stable patients. Data were analysed after a median of 30 months follow-up (range 16–48 months). In 42 patients, the immunologic response was studied and related to response and survival. The main toxicity were flu-like symptoms, malaise and transient liver enzyme elevations, necessitating IL-2 reduction to 2 mIU m−2 in 29 patients, which should be considered the maximal tolerable dose. The response was 24% (eight out of 34, three complete response (CR), five partial response (PR)) in patients with metachronic metastases and 12% (three out of 25, 2CR, 1PR) in patients with synchronic metastases. Overall response was 19% (11 out of 59). Median survival was 9.5 months. All tested patients showed expansion and/or activation of lymphocytes, T cells and subsets, NK cells, eosinophils and monocytes. Pretreatment HLA-DR levels on monocytes and number of CD4+HLA-DR+ cells correlated with response. Pretreatment number of CD4+HLA-DR+ cells and postimmunotherapy levels of lymphocytes, CD3+, CD4+ and CD8+ T cells, but not of NK or B cells, correlated with prolonged survival. Immunotherapy with concurrent subcutaneous GM-CSF, LD-IL-2 and IFNα has limited toxicity, can be given as outpatient treatment and can induce durable CR. Response and survival with this form of immunotherapy seem to be more dependent on expansion/activation of T cells than of NK cells.

Efficacy and toxicity of plasma-cell-reactive monoclonal antibodies B-B2 and B-B4 and their immunotoxins

Abstract Immunotherapy based on the delivery of toxic agents to the tumor site using monoclonal antibodies (mAb) may be a promising modality in the treatment of hematological malignancies. In the selection of mAb, both for ex vivo but even more for in vivo therapy, not only their reactivity to the neoplastic cells should be considered, but also reactivity to other body constituents. Here we describe the screening of two human plasma-cell-reactive mAb B-B2 and B-B4, which may be used for immunotherapy of multiple myeloma. Cross-reactivity of B-B2 and B-B4 was determined by immunohistochemistry on a series of tissues. This revealed for both B-B2 and B-B4 a strong staining of epithelial cells in various organs, e.g. lung, liver, skin, kidney and gut, while only a weak and diffuse staining was seen with endothelial cells. In bone marrow reactivity was only found with plasma cells and not with hemopoietic precursors (CD34+ cells). Immunotoxins from B-B2 and B-B4 were constructed by coupling them to the plant-derived ribosome-inactivating protein saporin. Both B-B2 and B-B4 immunotoxins appeared to be efficient in specific inhibition of protein synthesis in plasma cell lines (IC50 respectively 1 nM and 0.1 nm). The immunotoxins were also tested on epithelial cell line A431, on liver cell line HepG2 and on human umbilical vein endothelial cells. The epithelial cell line A431 was reactive with both B-B2 and B-B4, but was only inhibited by B-B4 immunotoxin. Cell line HepG2 was reactive with both mAb, but was not inhibited by either immunotoxin. The endothelial cells showed no reactivity with B-B2 and B-B4 and were not inhibited by either immunotoxin. Bone marrow treated with B-B2 and B-B4 immunotoxin did not show a decrease in colonies of hemopoietic precursor cells. Incubation of multiple-myeloma-derived bone marrow with these immunotoxin resulted in a clear decrease of the number of plasma cells.

B7-1 (CD80) as target for immunotoxin therapy for Hodgkin's disease.

In this preclinical study, the potential applicability of an anti-B7-1 immunotoxin (IT) for the treatment of Hodgkins disease (HD) was investigated. Immunohistochemical analysis demonstrated strong expression of B7-1 on Hodgkin and Reed-Sternberg (R-S) cells and clear expression on dendritic cells, macrophages and some B-cells in tissues, but not on other tissue cells. Flow cytometric analysis demonstrated that B7-1 was expressed on a few monocytes, but not on CD34+ cells from bone marrow, resting T- or B-cells from peripheral blood or epithelial and endothelial cell lines. An anti-B7-1 immunotoxin containing the anti-B7-1 monoclonal antibody (MAb) B7-24 and saporin as toxin moiety was constructed and showed an affinity similar to that shown by the native MAb. It exhibited strong cytotoxicity against the B7-1+ B-cell line Raji (IC50 10(-11) M), R-S cell lines HDLM2, KM/H2 and L428 and also against a B7-1-transfected epithelial cell line, A431, whose parental line lacks expression of B7-1. In clonogenic assays with Raji cells or KM/H2 cells, a 3- or 4-log kill, respectively, was observed. No cytotoxicity was found against the B7-1- epithelial and endothelial cell lines or against haematopoietic progenitor cells. In conclusion, an anti-B7-1 immunotoxin was developed that had good cytotoxicity against R-S cell lines and that may be used in the elimination of R-S cells in vivo. A concomitant elimination of activated antigen-presenting cells may avoid development of antitoxin and anti-mouse Ig responses and allow repeated administration.

Clinical perspectives of bispecific antibodies in cancer

The bispecific antibody (bsAb) field has come of age, but definite aproof of concepto in clinical studies is still eagerly awaited. The 5th World Conference on Bispecific Antibodies at Volendam, the Netherlands, is expected to unveil several of these studies. One of the main aims of bsAb is to develop alternatives or adjuncts for chemoand radiotherapy in cancer. We will give a personal perspective on the treatment of cancer, in which the choice of both the effector cells and the target antigen is of major importance.

RELEASE OF CYTOKINES AND SOLUBLE CELL SURFACE MOLECULES BY PBMC AFTER ACTIVATION WITH THE BISPECIFIC ANTIBODY CD3 X CD19

Bispecific antibodies (BsAb) consist of two different heavy and light chains and may bind to two different antigens present on different cell types. With their dual specificity BsAb may recognize effector cells (e.g. T cells) on one hand and tumour cells (e.g. malignant B cells) on the other hand. The authors analysed whether T cell activation and subsequent killing of malignant B cells mediated by the bispecific antibody CD3 × CD19 was reflected by the release of cytokines. In addition, the authors investigated whether the in vitro cytokine release was similar to that observed in vivo in the patients treated with BsAb. The in vitro release of cytokines into the supernatant of cell cultures of peripheral blood mononuclear cells (PBMC) and malignant B cells was measured after incubation with either the bispecific antibody CD3 × CD19 or the monospecific anti‐CD3 (aCD3) antibody in the presence or absence of interleukin (IL)‐2. Release of tumour necrosis factor‐α (TNF‐α), interferon‐γ (IFN‐γ), IL‐6, IL‐8, IL‐10, soluble (s) CD4, sCD8 and sCD25 by PBMC was equal under both conditions and could be used as an indicator for T cell activation. However, the cytokine pattern and level did not correlate with the cytotoxic capacity, which was 4 logs higher with BsAb + IL‐2 compared to aCD3 + IL‐2. The in vitro pattern of cytokine release was similar to that observed in vivo in the serum of patients treated with BsAb and IL‐2, indicating the possibility of predicting cytokine release in future patients with other therapeutic regimens.

Alloantigen-specific T-cell anergy induced by human keratinocytes is abrogated upon loss of cell-cell contact

The activation of primary human T cells largely depends on the expression of both major histocompatibility complex (MHC) class II and B7 molecules on antigen‐presenting cells (APC), whereas APC expressing HLA class II but not B7 antigens are expected to induce anergy. According to this concept, interferon‐γ (IFN‐γ)‐activated keratinocytes (KC) expressing HLA class II but not B7 costimulatory antigens should be able to induce anergy. However, in terms of anergy versus activation contradicting data have been published on the outcome of interaction between T cells and human KC. In addition, it has been shown that human KC can express a B7‐like molecule with unknown function, whereas MHC expression may be functionally impaired. To evaluate this item we transfected the human A431 KC cell line with B7‐1 coding sequences and up‐regulated HLA‐DR by treatment with IFN‐γ, yielding A431DR,B7‐1 cells. Irradiated A431DR,B7‐1 cells were found to be capable of inducing vigorous proliferative primary T‐cell responses in resting allogeneic T cells, whereas A431DR cells could induce proliferation only when interleukin‐2 (IL‐2) was added. These data indicate that KC can present alloantigens, and that lack of costimulatory molecules on KC is the main reason why these cells cannot induce primary T‐cell responses. Surprisingly, however, no evidence could be obtained of stable anergy induction by A431DR cells, as T cells contacted with A431DR cells and then transferred to A431DR,B7‐1 cells clearly demonstrated alloresponsiveness. T‐cell non‐responsiveness was maintained only when T cells remained in contact with A431DR cells. These data indicate that, despite expression of HLA class II in the absence of B7 costimulatory molecules, human KC cannot induce stable anergy but rather induce short‐term anergy in primary resting T cells.

HGF/SF and its receptor c-MET play a minor role in the dissemination of human B-lymphoma cells in SCID mice

SummaryThe MET protooncogene, c-MET, encodes a cell surface tyrosine kinase receptor. The ligand for c-MET is hepatocyte growth factor (HGF), also known as scatter factor (SF), which is known to affect proliferation and motility of primarily epithelial cells. Recently, HGF/SF was also shown to affect haemopoiesis. Studies with epithelial and transfected NIH3T3 cells indicated that the HGF/SF–c-MET interaction promotes invasion in vitro and in vivo. We previously demonstrated that HGF/SF induces adhesion of c-MET-positive B-lymphoma cells to extracellular matrix molecules, and promoted migration and invasion in in vitro assays. Here, the effect of HGF/SF on tumorigenicity of c-MET-positive and c-MET-negative human B-lymphoma cell lines was studied in C.B-17 scid/scid (severe combined immune deficient) mice. Intravenously (i.v.) injected c-MET-positive (BJAB) as well as c-MET-negative (Daudi and Ramos cells) B-lymphoma cells formed tumours in SCID mice. The B-lymphoma cells invaded different organs, such as liver, kidney, lymph nodes, lung, gonads and the central nervous system. We assessed the effect of human HGF/SF on the dissemination of the B-lymphoma cells and found that administration of 5 μg HGF/SF to mice, injected (i.v.) with c-MET-positive lymphoma cells, significantly (P = 0.018) increased the number of metastases in lung, liver and lymph nodes. In addition, HGF/SF did not significantly influence dissemination of c-MET-negative lymphoma cells (P = 0.350 with Daudi cells and P = 0.353 with Ramos cells). Thus the effect of administration of HGF/SF on invasion of lymphoma cells is not an indirect one, e.g. via an effect on endothelial cells. Finally, we investigated the effect of HGF/SF on dissemination of c-MET-transduced Ramos cells. In response to HGF/SF, c-MET-transduced Ramos cells showed an increased migration through Matrigel in Boyden chambers compared to wild-type and control-transduced Ramos cells. The dissemination pattern of c-MET-transduced cells did not differ from control cells in in vivo experiments using SCID mice. Also no effect of HGF/SF administration could be documented, in contrast to the in vitro experiments. From our experiments can be concluded that the HGF/SF–c-MET interaction only plays a minor role in the dissemination of human B-lymphoma cells.