Anti-CD30 antibody-based therapy

Targeted Radionuclide Therapy of Human Tumors

Targeted radionuclide therapy is one of the most intensively developing directions of nuclear medicine. Unlike conventional external beam therapy, the targeted radionuclide therapy causes less collateral damage to normal tissues and allows targeted drug delivery to a clinically diagnosed neoplastic malformations, as well as metastasized cells and cellular clusters, thus providing systemic therapy of cancer. The methods of targeted radionuclide therapy are based on the use of molecular carriers of radionuclides with high affinity to antigens on the surface of tumor cells. The potential of targeted radionuclide therapy has markedly grown nowadays due to the expanded knowledge base in cancer biology, bioengineering, and radiochemistry. In this review, progress in the radionuclide therapy of hematological malignancies and approaches for treatment of solid tumors is addressed.

Achieving incompatible transplantation through desensitization: current perspectives and future directions

The application of life-saving transplantation is severely limited by the shortage of organs, and histoincompatibility. To increase transplant rates in sensitized patients, new protocols for HLA and blood type incompatible (ABOi) desensitization have emerged. These approaches require significant desensitization using intravenous immunoglobulin, rituximab and plasma exchange. In addition, the development of donor-specific antibody responses post transplant is the major cause of allograft failure with return to dialysis. This increases patient morbidity/mortality and cost. Immunotherapeutic agents used for desensitization evolved from drug development in oncology and autoimmune diseases. Currently, there is a renaissance in development of novel drugs likely to improve antibody reduction in transplantation. These include agents that inactivate IgG molecules, anticytokine antibodies, costimulatory molecule blockade, anticomplement agents and therapies aimed at the plasma cell.

Development of anaplastic lymphoma kinase (ALK) small-molecule inhibitors for cancer therapy

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase (RTK) involved in the genesis of several human cancers; indeed, ALK was initially identified in constitutively activated and oncogenic fusion forms--the most common being nucleophosmin (NPM)-ALK--in a non-Hodgkin's lymphoma (NHL) known as anaplastic large-cell lymphoma (ALCL) and subsequent studies identified ALK fusions in the human sarcomas called inflammatory myofibroblastic tumors (IMTs). In addition, two recent reports have suggested that the ALK fusion, TPM4-ALK, may be involved in the genesis of a subset of esophageal squamous cell carcinomas. While the cause-effect relationship between ALK fusions and malignancies such as ALCL and IMT is very well established, more circumstantial links implicate the involvement of the full-length, normal ALK receptor in the genesis of additional malignancies including glioblastoma, neuroblastoma, breast cancer, and others; in these instances, ALK is believed to foster tumorigenesis following activation by autocrine and/or paracrine growth loops involving the reported ALK ligands, pleiotrophin (PTN) and midkine (MK). There are no currently available ALK small-molecule inhibitors approved for clinical cancer therapy; however, recognition of the variety of malignancies in which ALK may play a causative role has recently begun to prompt developmental efforts in this area. This review provides a succinct summary of normal ALK biology, the confirmed and putative roles of ALK fusions and the full-length ALK receptor in the development of human cancers, and efforts to target ALK using small-molecule kinase inhibitors.

Constitutive overexpression of a novel 21 kDa protein by Hodgkin lymphoma and aggressive non-Hodgkin lymphomas

Background

CD30, a 120 kDa surface phosphorylated protein is a member of tumour necrosis/nerve growth factor receptor (TNF/NGFR) family and constitutively expressed by Hodgkin and Reed-Sternberg (HRS) cells of Hodgkin lymphoma (HL) and the neoplastic cells of Anaplastic Large Cell Lymphoma (ALCL). A disease-specific protein marker is yet to be identified in Hodgkin lymphoma cells. In order to define HL-specific biomarkers, novel murine monoclonal antibodies were developed in our laboratory.

Results

Murine monoclonal antibodies (mabs) were raised against the B3 sub clone of HL-derived cell line KM-H2. Two of these mabs (clone R23.1 mab and clone R24.1 mab) are IgG₁ class antibodies that recognize a 21 kDa protein present at the cell membrane and in the cytoplasm in HL-derived cell lines. Clone R24.1 mab recognizes a formalin-resistant epitope and labels HRS cells in tissue samples from patients with HL of the classical type, ALCL, and subsets of T and B cell aggressive Non-Hodgkin Lymphomas (NHL). The antigen recognized by the clone R23.1 mab and clone R24.1 mab does not share epitopes with CD30 cluster regions A, B, or C, and, unlike CD30, is not expressed by phytohemagglutinin (PHA) activated T cells.

Conclusion

The 21 kDa protein detected by clone R23.1 and clone R24.1 mabs is a novel membrane-associated protein that may be a potential marker for the diagnosis and targeted therapy of HL and aggressive T and B cell NHL.

Effective therapy of murine models of human leukemia and lymphoma with radiolabeled anti-CD30 antibody, HeFi-1

CD30 is a member of the TNF receptor superfamily. Overexpression of CD30 on some neoplasms versus limited expression on normal tissues makes this receptor a promising target for antibody-based therapy. Radioimmunotherapy of cancer with radiolabeled antibodies has shown promise. In this study, we evaluated the therapeutic efficacy of an anti-CD30 antibody, HeFi-1, armed with (211)At in a leukemia (karpas299) model and with (90)Y in a lymphoma (SUDHL-1) model. Furthermore, we investigated the combination therapy of (211)At-HeFi-1 with unmodified HeFi-1 in the leukemia model. Treatment with unmodified HeFi-1 significantly prolonged the survival of the karpas299-bearing mice compared with the controls (P < 0.001). Treatment with (211)At-HeFi-1 showed greater therapeutic efficacy than that with unmodified HeFi-1 as shown by survival of the mice (P < 0.001). Combining these two agents further improved the survival of the mice compared with the groups treated with either (211)At-HeFi-1 (P < 0.05) or unmodified HeFi-1 (P < 0.001) alone. In the lymphoma model, the survival of the SUDHL-1-bearing mice was significantly prolonged by the treatment with (90)Y-HeFi-1 compared with the controls (P < 0.001). In summary, radiolabeled HeFi-1 is very promising for the treatment of CD30-expressing leukemias and lymphomas, and the combination regimen of (211)At-HeFi-1 with unmodified HeFi-1 enhanced the therapeutic efficacy.

Highly aggressive ALK-positive anaplastic large cell lymphoma with a leukemic phase and multi-organ involvement: a report of three cases and a review of the literature

Anaplastic large cell lymphoma (ALCL) is an aggressive neoplasm of T- or null cell phenotype and is recognized as a distinct clinicopathologic subtype of non-Hodgkin lymphoma (NHL) in the revised World Health Organization (WHO) classification of hematopoietic neoplasms. It is rarely associated with leukemic phase. Most cases with leukemic involvement are the small cell variant of ALCL. These cases often lack the pleomorphism seen in the common variant of ALCL and may be misdiagnosed. We report a series of three patients who presented with leukemic phase ALCL. The patients included an 11-year-old boy, a 29-year-old man, and a 59-year-old woman. The clinical and pathologic features of these cases are reviewed. The patients in our case series with leukemic phase ALCL exhibited rare clinical features. The patients presented with massive extranodal disease involving cerebrospinal fluid (CSF), liver, spleen, lungs, and bone marrow. CSF involvement was documented morphologically as well as by flow cytometry in two patients. Two of the patients had small cell variant and the third patient had common type ALCL. The neoplastic cells in all three patients were ALK positive; however these patients died within months of diagnosis. Leukemic phase ALCL is rare, and behaves in an aggressive manner. Some, but not all, cases in the literature presenting with peripheral blood involvement had small cell variant ALCL, as seen in two of our cases. The leukemic phase of ALCL should be considered when a T-cell leukemia with unusual morphologic features is encountered.

Effective therapy for a murine model of human anaplastic large-cell lymphoma with the anti-CD30 monoclonal antibody, HeFi-1, does not require activating Fc receptors

CD30 is a member of the tumor necrosis factor receptor family. Overexpression of CD30 on some neoplasms versus its limited expression on normal tissues makes this receptor a promising target for antibody-based therapy. Anaplastic large-cell lymphoma (ALCL) represents a heterogeneous group of aggressive non-Hodgkin lymphomas characterized by the strong expression of CD30. We investigated the therapeutic efficacy of HeFi-1, a mouse IgG1 monoclonal antibody, which recognizes the ligand-binding site on CD30, and humanized anti-Tac antibody (daclizumab), which recognizes CD25, in a murine model of human ALCL. The ALCL model was established by intravenous injection of karpas299 cells into nonobese diabetic/severe combined immuno-deficient (SCID/NOD) wild-type or SCID/NOD Fc receptor common gamma chain-deficient (FcRgamma(-/-)) mice. HeFi-1, given at a dose of 100 microg weekly for 4 weeks, significantly prolonged survival of the ALCL-bearing SCID/NOD wild-type and SCID/NOD FcRgamma(-/-) mice (P < .01) as compared with the control groups. In vitro studies showed that HeFi-1 inhibited the proliferation of karpas299 cells, whereas daclizumab did not inhibit cell proliferation. We demonstrated that the expression of FcRgamma on polymorphonuclear leukocytes and monocytes was not required for HeFi-1-mediated tumor growth inhibition in vivo, although it was required for daclizumab.

Cell membrane-specific epitopes on CD30: Potentially superior targets for immunotherapy

Because CD30 is highly expressed on Hodgkin's lymphoma and anaplastic large cell lymphoma, it is a promising target for immunotherapy. Soluble CD30, the extracellular domain of CD30 that is shed from the cells, can reduce the effects of CD30-targeting agents by competitive binding. In this study, we identified two epitopes on membrane-associated CD30 that are missing on soluble CD30 probably because of a conformational change upon shedding. These epitopes are potentially superior targets for immunotherapy because targeting them should be free from the competitive effects of soluble CD30. We studied 27 anti-native CD30 mAbs that were assigned to 8 different topographical epitopes. Soluble CD30 was prepared from culture supernatants of L540 cells or Karpas 299 cells. In an ELISA, the mAbs to two epitopes, Ep2 (amino acids 107-153) and Ep7 (amino acids 282-338), showed less than a 2% average cross-reactivity to soluble CD30 compared with a CD30-Fc fusion protein. In addition, these mAbs bound to CD30 on cells in the presence of an excess of soluble CD30. These epitopes (Ep2 and Ep7) are, therefore, more efficiently presented on cell-associated CD30 than on soluble CD30 (membrane-specific epitopes). Also, soluble CD30 in the sera of mice bearing L540 tumors did not form immune complexes with the membrane-specific mAbs analyzed by size-exclusion chromatography. In contrast, mAbs to the other epitopes reacted with both soluble CD30 and membrane CD30. Our results suggest that it may be possible to find membrane-specific epitopes on other immunotherapy target molecules.

Lymphomatoid papulosis from childhood with anaplastic large-cell lymphoma of the small bowel

Lymphomatoid papulosis (LyP) is a lymphoproliferative disorder that exists on a spectrum of diseases with cutaneous CD30+ anaplastic large-cell lymphoma (ALCL). Multiple treatment options are available, although none are curative. The typical age of onset for LyP is in the third and fourth decades, but it has been seen occasionally in children. Lymphomatoid papulosis is associated with primary cutaneous ALCL and other lymphoproliferative malignancies, but is rarely associated with extranodal systemic ALCL. A 43-year-old man developed lymphomatoid papulosis lesions at 3 years of age, which persisted into adulthood, and he later developed ALCL of the duodenum. Treatment with standard CHOP (cyclophosphamide/doxorubicin/vincristine/prednisolone) chemotherapy resulted in complete remission of his gastrointestinal lymphoma and temporary improvement of his skin lesions. However, the LyP relapsed and proved refractory to psoralen plus ultraviolet-A phototherapy, and was only temporarily and partially responsive to bexarotene and denileukin diftitox.

Anaplastic lymphoma kinase proteins in growth control and cancer

The normal functions of full-length anaplastic lymphoma kinase (ALK) remain to be completely elucidated. Although considered to be important in neural development, recent studies in Drosophila also highlight a role for ALK in gut muscle differentiation. Indeed, the Drosophila model offers a future arena for the study of ALK, its ligands and signalling cascades. The discovery of activated fusion forms of the ALK tyrosine kinase in anaplastic large cell lymphoma (ALCL) has dramatically improved our understanding of the pathogenesis of these lymphomas and enhanced the pathological diagnosis of this subtype of non-Hodgkin's lymphoma (NHL). Likewise, the realisation that a high percentage of inflammatory myofibroblastic tumours express activated-ALK fusion proteins has clarified the causation of these mesenchymal neoplasms and provided for their easier discrimination from other mesenchymal-derived inflammatory myofibroblastic tumour (IMT) mimics. Recent reports of ALK expression in a range of carcinoma-derived cell lines together with its apparent role as a receptor for PTN and MK, both of which have been implicated in tumourigenesis, raise the possibility that ALK-mediated signalling could play a role in the development and/or progression of a number of common solid tumours. The therapeutic targeting of ALK may prove to have efficacy in the treatment of many of these neoplasms.

Novel agents for cutaneous T-cell lymphoma

Several novel therapies have recently emerged for the treatment of hematologic malignancies; several agents have demonstrated activity against T-cell lymphomas in vitro or in early clinical trials. This article discusses how these therapies may be implemented in the treatment of patients who have advanced or refractory cutaneous T-cell lymphoma.

DNA immunization followed by a single boost with cells: a protein-free immunization protocol for production of monoclonal antibodies against the native form of membrane proteins

Recent advancements in antibody-based therapies require the development of an efficient method for generation of monoclonal antibodies (MAbs) against the native form of membrane proteins. We examined DNA immunization followed by a single boost with cells as a protein-free immunization protocol for production of MAbs. Mice immunized with plasmid cDNAs encoding human CD30 or Ret tyrosine kinase were given a single boost with cells expressing the corresponding antigen prior to cell fusion. A total of nine cell fusion experiments revealed that the cell boost is necessary for efficient generation of hybridomas and the DNA-cell boost method gave good yields of specific MAbs (5-59 MAbs from one mouse). All IgG isotypes except IgG3 were generated, although IgG2a was the dominant isotype. All the MAbs reacted with native antigens expressed on cells in a fluorescence-activated cell sorter (FACS) analysis as well as with recombinant CD30 or Ret protein genetically fused with human Fc in an enzyme-linked immunosorbent assay (ELISA). The affinities of the anti-CD30 MAbs to CD30-Fc protein ranged from 0.9 to 12.4 nM Kds, which were comparable to existing MAbs to these proteins, which range from 3.0 to 13.0 nM. Western blot analysis and topographical epitope mapping experiments based on the mutual competition of pairs of the anti-CD30 MAbs revealed that about 40% of the epitopes were linear epitopes and that each epitope was topographically classified into one of six groups. The large number of MAbs that react with high affinities to a variety of epitopes on the native form of antigens indicates that the method presented in this paper could be generally useful for generating MAbs to other membrane proteins.

Clinical implications of the tumor necrosis factor family in benign and malignant hematologic disorders

Tumor necrosis factor (TNF), originally identified as a factor produced in the serum of endotoxin-injected animals, is a cytokine that mediates tumor necrosis. To date, 20 different members of the TNF superfamily and 21 different receptors have been identified. All ligands of the TNF superfamily have been found to activate transcription factor NF-kappaB and c-Jun kinase. Members of this family have diverse biologic effects, including induction of apoptosis, promotion of cell survival, and regulation of the immune system. The current review focuses on four members that play important roles in regulating hematopoietic cells and are involved in the pathogenesis of several hematologic malignancies. The potential therapeutic use of these members also is discussed.

Peripheral T-cell lymphoma

Peripheral (post-thymic) T-cell lymphoma consists of a wide spectrum of disorders with marked differences in biology and behavior. Proper classification is pivotal for evaluating treatment results, and most studies performed a decade ago lump together different disease entities and cannot be interpreted. With improved use of immunophenotyping and molecular methods for these disorders, their exact nature is better defined in the Revised European-American Lymphoma and subsequent World Health Organization (WHO) classifications. The WHO classification of post- thymic T/natural killer (NK)-cell lymphoma consists of 15 entities, including about 30% that are unclassified cases. A wide range in incidence exists between different populations, but it is likely to be lower than previously estimated. Certain entities, like nasal/nasal-type T/NK-cell lymphoma and human T-cell leukemia/lymphoma virus 1, are much more prevalent in certain racial groups and show exquisite viral association. In these entities as a group, prognosis and treatment seem inferior to those of their B-cell counterparts, but treatment must be tailored to the exact pathologic diagnosis and prognostic index. Aggressive combination chemotherapy appears to be curative for certain entities (eg, anaplastic lymphoma kinase-positive), whereas purine analogues may be useful for low-grade entities. The role of autologous and allogeneic stem cell transplantation is still poorly defined. Specific antibody-based therapy is also on the horizon.

Inhibition of metalloproteinases enhances the internalization of anti-CD30 antibody Ki-3 and the cytotoxic activity of Ki-3 immunotoxin

CD30 is selectively expressed on the tumor cells of a variety of malignant disorders of the immune system and can therefore be used as a target for an anti-CD30 antibody-based immunotherapy. However, CD30 is cleaved at the cell surface by tumor necrosis factor-alpha converting enzyme (TACE). This metalloproteinase releases the soluble ectodomain of CD30 (sCD30), which is able to neutralize immunotherapeutic agents before these reach their target cells. Such constitutive CD30 cleavage is enhanced after binding of most anti-CD30 antibodies, leading to a downregulation of CD30 and an increase of sCD30 in the cell environment. Here, we demonstrate that CD30 shedding from the cell line Karpas 299 could effectively be blocked by the hydroxamic acid-based metalloproteinase inhibitors BB-3644 (IC50 = 180 nM), BB-2116 (IC50 = 230 nM), BB-94 (batimastat, IC50 = 230 nM) and BB-2516 (marimastat, IC50 = 1 microM). This inhibition reduced the concentration of sCD30 in the cell environment to the background level, prolonged the persistence of the anti-CD30 antibody Ki-3 on Karpas 299 cells and favored its internalization. Moreover, a nontoxic concentration of the inhibitor BB-3644 significantly increased the cytotoxic activity of the anti-CD30 ricin A-chain immunotoxin Ki-3.dgA towards the CD30(+) Hodgkin-derived cell line L540. Hence, the metalloproteinase inhibitor BB-3644 may be a promising compound to improve the immunotherapy of CD30(+) malignancies.