Clinical and Immune Responses in Advanced Melanoma Patients Immunized With an Anti-Idiotype Antibody Mimicking Disialoganglioside GD2

PURPOSE: To determine immune responses and toxicity to the anti-idiotype vaccine, as well as clinical responses and survival, we initiated a clinical trial for patients with advanced melanoma treated with an anti-idiotype antibody (TriGem) that mimics the disialoganglioside GD2. PATIENTS AND METHODS: Forty-seven patients with advanced melanoma received either 1-, 2-, 4-, or 8-mg doses of TriGem (Titan Pharmaceuticals Inc, South San Francisco, CA) mixed with QS-21 adjuvant (Aquila Biopharmaceuticals, Inc, Worcester, MA) 100 μg subcutaneously weekly for 4 weeks and then monthly until disease progression. Median age was 57 years, there were 32 men and 15 women, 43% of patients had undergone prior therapy for metastatic disease, 55% had disease confined to soft tissue, and 45% had visceral metastasis. RESULTS: Hyperimmune sera from 40 of 47 patients showed an anti–anti-idiotype (Ab3) response. Patient Ab3 was truly Ab1′ because it specifically bound purified disialoganglioside GD2. The isotypic specificity of the Ab3 antibody consisted of predominantly immunoglobulin (Ig)G, and all IgG subclasses were represented. One patient had a complete response that persisted at 24 months, and 12 patients were stable from 14+ to 37+ months (median, 18+ months). Disease progression occurred in 32 patients on study from 1 to 17 months (median, 5.5 months), and 21 have died at 1 to 16 months (median, 6 months). The Kaplan-Meier–derived overall median survival has not been reached. Median survival has not been reached for the 26 patients with soft tissue disease only and was 13 months for 21 patients with visceral metastasis. Toxicity consisted of local reaction at the site of injection and mild fever and chills. CONCLUSION: TriGem has minimal toxicity and generates robust and specific IgG immune responses against GD2. Objective responses were minimal, but there may be a favorable impact on disease progression and survival that will require prospective randomized trials

Overcoming Drug-Resistant Cancer by a Newly Developed Copper Chelate throughHost-Protective Cytokine-MediatedApoptosis

Previously, we have synthesized and characterized a novel Cu(II) complex, copper N-(2-hydroxy acetophenone) glycinate (CuNG).Herein,wehave determined the efficacyofCuNG in overcomingmultidrug-resistant cancer using drug-resistantmurine and human cancer cell lines. Experimental Design: Action of CuNG following single i.m. administration (5 mg/kg body weight) was tested in vivo on doxorubicin-resistant Ehrlich ascites carcinoma (EAC/Dox)^ bearing mice and doxorubicin-resistant sarcoma 180^ bearing mice.Tumor size, ascitic load, and survival rates were monitored at regular intervals. Apoptosis of cancer cells was determined by cellcy cle analysis, confocal microscopy, Annexin V binding, and terminald eoxynucleotidyl transferase ^mediated dUTP nick end labeling assay ex vivo. IFN-g and tumor necrosis factor-a were assayed in the culture supernatants of in vivo and in vitro CuNG-treated splenic mononuclear cells from EAC/Dox-bearing mice and their apoptogenic effect was determined. Source of IFN-g and changes in number of Tregulatory marker-bearing cells in the tumor site following CuNG treatment were investigated by flow cytometry. Supernatants of in vitro CuNG-treated cultures of peripheral blood mononuclear cells from different drug-insensitive cancer patients were tested for presence of the apoptogenic cytokine IFN-g and its involvement in induction of apoptosis of doxorubicin-resistant CEM/ADR5000 cells. Results: CuNGtreatment could resolve drug-resistant cancers through induction of apoptogenic cytokines, such as IFN-g and/or tumor necrosis factor-a, from splenic mononuclear cells or patient peripheral bloodmononuclear cells and reduce the number ofTregulatory marker-bearing cells while increase infiltration of IFN-g-producingTcells in the ascetic tumor site. Conclusion: Our results show the potential usefulness of CuNG in immunotherapy of drugresistant cancers irrespective of multidrug resistance phenotype

A new Mad2-interacting domain of Cdc20 is critical for the function of Mad2–Cdc20 complex in the spindle assembly checkpoint

Interaction between Mad2 and Cdc20 (cell division cycle 20) is a key event during spindle assembly checkpoint activation. In the past, an N-terminal peptide containing amino acid residues 111–150 of Cdc20 was shown to bind Mad2 much better than the full-length Cdc20 protein. Using co-localization, co-immunoprecipitation and peptide inhibition analysis with different deletion mutants of Cdc20, we identified another Mad2-binding domain on Cdc20 from amino acids 342–355 within the WD repeat region. An intervening region between these two domains interferes with its Mad2 binding when present individually with any of these two Mad2-binding sites. We suggest that these three domains together determine the overall strength of Mad2 binding with Cdc20. Functional analysis suggests that an optimum Mad2 binding efficiency of Cdc20 is required during checkpoint arrest and release. Further, we have identified a unique polyhistidine motif with metal binding property adjacent to this second binding domain that may be important for maintaining the overall conformation of Cdc20 for its binding to Mad2