Effective immunochemotherapy for aggressive non-Hodgkin's lymphoma

Design of Coltuximab Ravtansine, a CD19-Targeting Antibody-Drug Conjugate (ADC) for the Treatment of B-Cell Malignancies: Structure-Activity Relationships and Preclinical Evaluation

Coltuximab ravtansine (SAR3419) is an antibody-drug conjugate (ADC) targeting CD19 created by conjugating a derivative of the potent microtubule-acting cytotoxic agent, maytansine, to a version of the anti-CD19 antibody, anti-B4, that was humanized as an IgG1 by variable domain resurfacing. Four different linker-maytansinoid constructs were synthesized (average ∼3.5 maytansinoids/antibody for each) to evaluate the impact of linker-payload design on the activity of the maytansinoid-ADCs targeting CD19. The ADC composed of DM4 (N(2')-deacetyl-N(2')-[4-mercapto-4-methyl-1-oxopentyl]maytansine) conjugated to antibody via the N-succinimidyl-4-(2-pyridyldithio)butyrate (SPDB) linker was selected for development as SAR3419. A molar ratio for DM4/antibody of between 3 and 5 was selected for the final design of SAR3419. Evaluation of SAR3419 in Ramos tumor xenograft models showed that the minimal effective single dose was about 50 μg/kg conjugated DM4 (∼2.5 mg/kg conjugated antibody), while twice this dose gave complete regressions in 100% of the mice. SAR3419 arrests cells in the G2/M phase of the cell cycle, ultimately leading to apoptosis after about 24 h. The results of in vitro and in vivo studies with SAR3419 made with DM4 that was [(3)H]-labeled at the C20 methoxy group of the maytansinoid suggest a mechanism of internalization and intracellular trafficking of SAR3419, ultimately to lysosomes, in which the antibody is fully degraded, releasing lysine-N(ε)-SPDB-DM4 as the initial metabolite. Subsequent intracellular reduction of the disulfide bond between linker and DM4 generates the free thiol species, which is then converted to S-methyl DM4 by cellular methyl transferase activity. We provide evidence to suggest that generation of S-methyl DM4 in tumor cells may contribute to in vivo tumor eradication via bystander killing of neighboring tumor cells. Furthermore, we show that S-methyl DM4 is converted to the sulfoxide and sulfone derivatives in the liver, suggesting that hepatic catabolism of the payload to less cytotoxic maytansinoid species contributes to the overall therapeutic window of SAR3419. This compound is currently in phase II clinical evaluation for the treatment of diffuse large B cell lymphoma.

Rare case of primary pleural lymphoma presenting with pleural effusion

Primary pleural lymphoma is rare and has been described in association with human immunodeficiency virus (HIV) infection or pyothorax. We report a rare case of primary pleural lymphoma in a 73-year-old man who presented with chest pain and no history of HIV infection or pyothorax. Chest imaging showed pleural thickening and pleural effusion. Thoracoscopic pleural biopsy was performed. Histopathological and immunohistochemical examinations conformed to that of a diffuse large B-cell lymphoma. Physicians should be aware of this rare location of primary lymphoma and implement thoracoscopy as soon as possible.

Retargeting NK-92 cells by means of CD19- and CD20-specific chimeric antigen receptors compares favorably with antibody-dependent cellular cytotoxicity

Multiple natural killer (NK) cell-based anticancer therapies are currently under development. Here, we compare the efficiency of genetically modified NK-92 cells expressing chimeric antigen receptors (CARs) at killing NK cell-resistant B-lymphoid leukemia cells to the antibody-dependent cell-mediated cytotoxicity (ADCC) of NK-92 cells expressing a high affinity variant of the IgG Fc receptor (FcγRIII). First, we compared in vitro the abilities of NK-92 cells expressing CD20-targeting CARs to kill primary chronic lymphocytic leukemia (CLL) cells derived from 9 patients with active, untreated disease to the cytotoxicity of NK-92 cells expressing FcγRIII combined with either of the anti-CD20 monoclonal antibodies (mAbs) rituximab or ofatumumab. We found that CAR-expressing NK-92 cells effectively kill NK cell-resistant primary CLL cells and that such a cytotoxic response is significantly stronger than that resulting from ADCC. For studying CAR-expressing NK cell-based immunotherapy in vivo, we established xenograft mouse models of residual leukemia using the human BCR-ABL1+ cell lines SUP-B15 (CD19+CD20-) and TMD-5 (CD19+CD20+), two acute lymphoblastic leukemia (ALL) lines that are resistant to parental NK-92 cells. Intravenous injection of NK-92 cells expressing CD19-targeting CARs eliminated SUP-B15 cells, whereas they had no such effect on TMD-5 cells. However, the intrafemoral injection of NK-92 cells expressing CD19-targeting CAR resulted in the depletion of TMD-5 cells from the bone marrow environment. Comparative studies in which NK-92 cells expressing either CD19- or CD20-targeting CARs were directly injected into subcutaneous CD19+CD20+ Daudi lymphoma xenografts revealed that CD20-targeting CAR is superior to its CD19-specific counterpart in controlling local tumor growth. In summary, we show here that CAR-expressing NK-92 cells can be functionally superior to ADCC (as mediated by anti-CD20 mAbs) in the elimination of primary CLL cells. Moreover, we provide data demonstrating that the systemic administration of CAR-expressing NK-92 cells can control lymphoblastic leukemia in immunocompromised mice. Our results also suggest that the direct injection of CAR-expressing NK-92 cells to neoplastic lesions could be an effective treatment modality against lymphoma.

Diagnostic Impact of Molecular Lineage Analysis on Paraffin-Embedded Tissue in Hematolymphoid Neoplasia Reclassified by Current WHO Criteria

BACKGROUND AND OBJECTIVE

By current WHO criteria, most - though not all - cases of hematolymphoid neoplasm can be diagnosed immunomorphologically, diminishing the role of molecular tests for lymphoid antigen receptor clonality in lymphoma diagnosis. Hence, our objective was to glean immunomorphological and molecular correlates from hematolymphoid neoplasms that had remained unresolvable without diagnostic molecular input.

METHODS

Thirty-five such cases were reviewed histologically and with standard immunoperoxidases. In situ hybridization for Epstein-Barr virus (EBV)-encoded RNAs (EBER) was performed on selected cases. PCR amplification of genes encoding T-cell receptors (TcR) and immunoglobulin heavy chains (IgH) [TR and IGH genes, respectively] was performed on whole tissue in all cases, and on microdissected cells in two cases.

RESULTS

Twenty-five cases (71%) requiring diagnostic molecular genotyping had some form of peripheral T-cell lymphoma (PTCL). Twenty (80%) of these were complicated by a proliferation of B-lineage cells, either within the same tissue ('syntopic') as large B cells (LBC) or Reed-Sternberg (RS)-like cells (17 cases), florid lymphoid hyperplasia (two cases, one also with syntopic LBC) or monotypic plasma cells (one case), or at a separate ('metatopic') site as a B-cell lymphoma (two cases, one of which also had syntopic LBC) or Hodgkin lymphoma (HL; one case, also showing syntopic LBC). Fifteen (75%) of these 20 PTCLs with B-lineage proliferation yielded monoclonal TR gene rearrangements, and only two (10%) showed IGH monoclonality, which was transient in one case. Three (18%) of the PTCLs with LBC had originally been misinterpreted as some form of HL. Conversely, of the remaining cases, three of four (75%) that had been diagnosed initially as some form of large cell non-HL (NHL), including two of three that were called 'anaplastic', had to be revised to grade II/syncytial nodular sclerosing (NS) HL, yielding polyclonal TcRgamma gene (TRG) rearrangements, with one case, in addition, disclosing a biallelic clonal IGH gene rearrangement that excluded anaplastic large cell lymphoma.

DISCUSSION/CONCLUSION

Paradoxically, monoclonality of TR rather than IGH gene rearrangement may more often be detectable in a predominantly dispersed ('hodgkinoid'), large B-lineage cell proliferation, consistent with release from immune regulation in the milieu of impaired immunosurveillance within a PTCL. This is compounded by the difficulty in ascertaining clonal IGH gene rearrangements resulting from (1) poor consensus primer hybridization due to somatic hypermutations, and (2) 'dilution' in a T-cell-rich milieu. These same difficulties also account for the long-elusive identification of the RS cell lineage. Conversely, anaplastic lymphoma, which is of non-B lineage, may be mimicked by NSHL, which is of B lineage.

Overexpression of BMI-1 correlates with drug resistance in B-cell lymphoma cells through the stabilization of survivin expression

The expression of BMI-1 is correlated with disease progression in cancer patients. We showed that ectopic expression of BMI-1 in B-cell lymphoma cell lines, HT and RL, conferred resistance to etoposide and oxaliplatin, known to enhance sensitivity by targeting the survivin gene, but not to irinotecan, which is not relevant to the downregulation of survivin expression. The expression of survivin was not only augmented in cells transduced with BMI-1, but persisted in the presence of etoposide in cells overexpressing BMI-1. By contrast, the mock-transduced cells succumbed in the medium with anticancer drugs, with an accompanying decrease in BMI-1 and survivin expression. BMI-1 overexpression stabilized survivin post-translationally without an accompanying rise in the mRNA, suggesting survivin as a potential target for BMI-1. Knockdown of either BMI-1 or survivin restored sensitivity to etoposide in the BMI-1-overexpressing lymphoma cells. An analysis of six patients with B-cell lymphoma showed that in the drug-resistant patients, levels of BMI-1 and survivin were maintained even after drug administration. However, downregulation of both BMI-1 and survivin expression was observed in the drug-sensitive patients. Therefore, BMI-1 might facilitate drug resistance in B-cell lymphoma cells through the regulation of survivin. BMI-1 could be an important prognostic marker as well as a future therapeutic target in the treatment of drug-resistant lymphomas.

Bortezomib Plus CHOP-Rituximab for Previously Untreated Diffuse Large B-Cell Lymphoma and Mantle Cell Lymphoma

Purpose

The proteasome inhibitor bortezomib may enhance activity of chemoimmunotherapy in lymphoma. We evaluated dose-escalated bortezomib plus standard cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus rituximab (R) in patients with diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL).

Patients and Methods

Seventy-six subjects with untreated DLBCL (n = 40) and MCL (n = 36) received standard CHOP every 21 days (CHOP-21) with R plus bortezomib at 0.7 mg/m2(n = 4), 1.0 mg/m2(n = 9), or 1.3 mg/m2(n = 63) on days 1 and 4 for six cycles.

Results

Median age was 63 years (range, 20 to 87), and International Prognostic Index (IPI) scores were generally unfavorable (39% with IPI of 2, and 49% with IPI of 3 to 5), as were Mantle Cell Lymphoma International Prognostic Index scores in patients with MCL (28% intermediate risk and 39% high risk). Toxicity was manageable, including neuropathy in 49 subjects (8% grade 2 and 4% grade 3) and grade 3/4 anemia (13%), neutropenia (41%), and thrombocytopenia (25%). For DLBCL, the evaluable overall response rate (ORR) was 100% with 86% complete response (CR)/CR unconfirmed (CRu; n = 35). Intent-to-treat (ITT, n = 40) ORR was 88% with 75% CR/CRu, 2-year progression-free survival (PFS) of 64% (95% CI, 47% to 77%) and 2-year overall survival (OS) of 70% (95% CI, 53% to 82%). For MCL, the evaluable ORR was 91% with 72% CR/CRu (n = 32). The ITT (n = 36) ORR was 81% with 64% CR/CRu, 2-year PFS 44% (95% CI, 27% to 60%) and 2-year OS 86% (95% CI, 70% to 94%). IPI and MIPI correlated with survival in DLBCL and MCL, respectively. Unlike in DLBCL treated with R-CHOP alone, nongerminal center B cell (non-GCB) and GCB subtypes had similar outcomes.

Conclusion

Bortezomib with R-CHOP-21 can be safely administered and may enhance outcomes, particularly in non-GCB DLBCL, justifying randomized studies.

Synergistic and persistent effect of T-cell immunotherapy with anti-CD19 or anti-CD38 chimeric receptor in conjunction with rituximab on B-cell non-Hodgkin lymphoma

Using artificial receptors, it is possible to redirect the specificity of immune cells to tumour-associated antigens, which is expected to provide a useful strategy for cancer immunotherapy. Given that B-cell non-Hodgkin lymphoma (B-NHL) cells invariably express CD19 and CD38, these antigens may be suitable molecular candidates for such immunotherapy. We transduced human peripheral T cells or a T-cell line with either anti-CD19-chimeric receptor (CAR) or anti-CD38-CAR, which contained an anti-CD19 or anti-CD38 antibody-derived single-chain variable domain respectively. Retroviral transduction led to anti-CD19-CAR or anti-CD38-CAR expression in T cells with high efficiency (>60%). The T cell line, Hut78, when transduced with anti-CD19-CAR or anti-CD38-CAR, exerted strong cytotoxicity against the B-NHL cell lines, HT and RL, and lymphoma cells isolated from patients. Interestingly, use of both CARs had an additive cytotoxic effect on HT cells in vitro. In conjunction with rituximab, human peripheral T cells expressing either anti-CD19-CAR or anti-CD38-CAR enhanced cytotoxicity against HT-luciferase cells in xenografted mice. Moreover, the synergistic tumour-suppressing activity was persistent in vivo for over 2 months. These results provide a powerful rationale for clinical testing of the combination of rituximab with autologous T cells carrying either CAR on aggressive or relapsed B-NHLs.

Effective treatment of a peripheral T-cell lymphoma/lymphoepitheloid cell variant (Lennert's lymphoma) refractory to chemotherapy with the CD-52 antibody alemtuzumab

Lymphoepitheloid cell lymphoma (Lennert's lymphoma) is a rare malignant disease usually affecting patients at advanced age. Although classified as a "low-grade" lymphoma in the past, the clinical course is highly unfavorable and currently available chemotherapeutic regimens have given disappointing results. We present the case of a 74-year-old male suffering from disseminated Lennert's lymphoma. The patient underwent standard treatment approaches including chemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP); fludarabin and cyclophosphamide; and ifosfamide, carboplatin and etoposide (ICE). Due to progressive disease with all these regimens, chemotherapy was discontinued. As cells stained highly positive for CD52, immunotherapy with alemtuzumab (Campath-1H) was started using a standard dosing regime of 30 mg every third day. Although the patient received prophylactic anti-infective medication, leucocytopenia with reactivation of cytomegalovirus (CMV) infection was observed and the administration of alemtuzumab had to be stopped temporarily. Re-assessment of disease 5 weeks after the start of alemtuzumab disclosed a significant reduction of all thoracic and abdominal lesions, and therapy with alemtuzumab was continued after normalization of the number of CMV copies and is currently ongoing. Our observations indicate clinical activity of alemtuzumab in the treatment of Lennert's lymphoma, including even bulky nodal disease, particularly for patients who have failed conventional therapies.

Treatment of Conjunctival Lymphomas

Due to their indolent nature, conjunctival lymphomas have different treatment options compared to other adnexal lymphomas. Therapeutic options directed towards conjunctival lymphomas include radiotherapy (external beam radiation), brachytherapy, cryotherapy, intralesional interferon injections, systemic rituximab, and observation. Radiotherapy that has been demonstrated to be highly effective for both low and high-grade tumors, however, can be associated with a high percentage of short-term side effects and long-term complications. Brachytherapy can provide local tumor control, but can also cause many complications. Cryotherapy may be used for certain tumor locations, but has a high recurrence rate. Both interferon and rituximab show promising results for treating low-grade tumors while avoiding the complications associated with radiotherapy. Finally, reports of spontaneous regression of low-grade conjunctival lymphomas have led some investigators to advocate a course of careful observation following biopsy.

Rituximab in chronic cold agglutinin disease: a prospective study of 20 patients

Chronic cold agglutinin disease (CAD) is an acquired autoimmune hemolytic anemia. Previous therapeutic modalities, including alkylating cytostatics, interferon and prednisolone, have been disappointing. However, several case reports and small-scaled studies have demonstrated promising results after treatment with rituximab. We performed a phase II multicentre trial to investigate the effect of rituximab in CAD, including 20 patients studied from October 2002 until April 2003. Thirteen patients had idiopathic CAD and seven patients had CAD associated with a malignant B-cell lymphoproliferative disease. Rituximab was given in doses of 375 mg/m(2) at days 1, 8, 15 and 22. Sixteen patients were followed up for at least 48 weeks. Four patients were excluded after 8, 16, 23 and 28 weeks for reasons unrelated to CAD. Nine patients (45%) responded to the treatment, one with complete response (CR), and eight with partial response. Eight patients relapsed, one patient was still in remission at the end of follow-up. There were no serious rituximab-related side-effects. Our study confirms previous findings of a favourable effect of rituximab in patients with CAD. However, few patients will obtain CR and, in most patients, the effect will be transient.

CD20-directed small modular immunopharmaceutical, TRU-015, depletes normal and malignant B cells

PURPOSE

CD20-directed therapy with rituximab is effective in many patients with malignant lymphoma or follicular lymphoma. However, relapse frequently occurs within 1 year, and patients become increasingly refractory to retreatment. Our purpose was to produce a compact, single-chain CD20-targeting immunotherapeutic that could offer therapeutic advantages in the treatment of B-cell lymphoma.

EXPERIMENTAL DESIGN

Rituximab is a chimeric antibody containing two heavy chains and two light chains. Here, we describe the properties of TRU-015, a small modular immunopharmaceutical specific for CD20, encoded by a single-chain construct containing a single-chain Fv specific for CD20 linked to human IgG1 hinge, CH2, and CH3 domains but devoid of CH1 and CL domains.

RESULTS

TRU-015 mediates potent direct signaling and antibody-dependent cellular cytotoxicity but has reduced size and complement-mediated cytotoxicity activity compared with rituximab. TRU-015 is a compact dimer of 104 kDa that comigrates with albumin in size exclusion chromatography and retains a long half-life in vivo. TRU-015 induced growth arrest in multiple B lymphoma cell lines in vitro and showed effective antitumor activity against large, established subcutaneous Ramos or Daudi xenograft tumors in nude mice. TRU-015 also showed rapid, dose-dependent, and durable depletion of peripheral blood B cells following single-dose administration to nonhuman primates.

CONCLUSION

These results indicate that TRU-015 may improve CD20-directed therapy by effectively depleting embedded malignant B cells and nonmalignant pathogenic B cells and do so with reduced complement activation.

Yttrium 90 ibritumomab tiuxetan (Zevalin®): A new bullet in the fight against malignant lymphoma?

Targeted immunotherapy utilizing monoclonal antibodies has improved survival in both indolent and aggressive lymphoma significantly. Since malignant lymphomas are also responsive to radiation, the combination of targeted immunotherapy and radiation with radionuclide coupled to monoclonal antibodies is an attractive option to further improve treatment results. Zevalin is a commercially available variation of the murine anti-CD20 antibody ibritumomab coupled to Yttrium 90 via the tiuxetan chelator. The development of this novel drug as well as the results of the pivotal studies and clinical strategies to implement this treatment into the routine practice of lymphoma oncology are presented in this review.

Recombinant interleukin-2 significantly augments activity of rituximab in human tumor xenograft models of B-cell non-Hodgkin lymphoma

Recombinant interleukin-2 (rIL-2) is a pleiotropic cytokine that activates select immune effector cell responses associated with antitumor activity, including antibody-dependent cellular cytotoxicity (ADCC). Rituximab is an anti-CD20 monoclonal antibody that activates ADCC in non-Hodgkin lymphoma (NHL). The ability of rIL-2 to augment rituximab-dependent tumor responses was investigated. The efficacy of rIL-2 in combination with rituximab was evaluated in 2 NHL tumor xenograft models: the CD20hi, rituximab-sensitive, low-grade Daudi model and the CD20lo, aggressive, rituximab-resistant Namalwa model. Combination of rIL-2 plus rituximab was synergistic in a rituximab-sensitive Daudi tumor model, as evidenced by significant tumor regressions and increased time to tumor progression, compared with rIL-2 and rituximab single agents. In contrast, rituximab-resistant Namalwa tumors were responsive to single-agent rIL-2 and showed an increased response when combined with rituximab. Using in vitro killing assays, rIL-2 was shown to enhance activity of rituximab by activating ADCC and lymphokine-activated killer activity. Additionally, the activity of rIL-2 plus rituximab F(ab')2 was similar to that of rIL-2 alone, indicating a critical role for immunoglobulin G1 Fc-FcgammaR-effector responses in mediating ADCC. Antiproliferative and apoptotic tumor responses, along with an influx of immune effector cells, were observed by immunohistochemistry. Collectively, the data suggest that rIL-2 mediates potent tumoricidal activity against NHL tumors, in part, through activation and trafficking of monocytes and natural killer cells to tumors. These data support the mechanistic and therapeutic rationale for combination of rIL-2 with rituximab in NHL clinical trials and for single-agent rIL-2 in rituximab-resistant NHL patients.

Immune selective pressure and HLA class I antigen defects in malignant lesions

The revived cancer immune surveillance theory has emphasized the active role the immune system plays in eliminating tumor cells and in facilitating the emergence of their immunoresistant variants. MHC class I molecule abnormalities represent, at least in part, the molecular phenotype of these escape variants, given the crucial role of MHC class I molecules in eliciting tumor antigen-specific T cell responses, the high frequency of HLA class I antigen abnormalities in malignant lesions and their association with a poor clinical course of the disease. Here, we present evidence for this possibility and review the potential mechanisms by which T cell selective pressure participates in the generation of tumor cells with MHC class I molecule defects. Furthermore, we discuss the strategies to counteract tumor cell immune evasion.

Antibody therapy in non-Hodgkin's lymphoma: the role of rituximab, 90Y-ibritumomab tiuxetan, and alemtuzumab

Targeting cancer cells with monoclonal antibodies has become an indispensable part of modern treatment against hematologic malignancies. The excitement of the first successful experimental results could be confirmed by large multicenter trials, thus paving the way for new approaches in first-line, relapse, and maintenance therapy. Three antibodies--rituximab, 90Y-ibritumomab tiuxetan, and alemtuzumab--are in clinical use worldwide and are reviewed in this chapter with a focus on practical information and fundamental principles of antibody-based therapy.

Treatment and survival for non-Hodgkin’s lymphoma: Influence of histological subtype, age, and other factors in a population-based study (1999–2001)

AIMS

This population-based study investigates the use of chemotherapy and radiotherapy for non-Hodgkin's lymphoma (NHL) treatment in clinical practise generally, and for specific histologies, and identifies factors associated with treatment and survival.

METHODS

Data for NHL patients, diagnosed during 1999-2001, were obtained from the National Cancer Registry (Ireland). Multivariate models were analysed on survival and treatment.

RESULTS

45-77% of patients received chemotherapy, 22-34% of patients received the radiotherapy, depending on the histology. Patients aged <65, married, with early stage B-cell aggressive disease were more likely to receive chemotherapy (P<0.05). Patients >65 or with advanced stage were less likely to receive radiation (P<0.05). Survival was poorer in older (P<0.001) and unmarried patients (P<0.05), and those with B-cell aggressive lymphoma (P<0.001). Patients who received chemotherapy and radiation had lower hazard ratios.

CONCLUSIONS

Overall, the use of chemotherapy and radiation in this European population was similar to the findings in the US where older patients received treatment less often. However, the age disparity here was greater than that in the US.

Magnitude of Stromal Hemangiogenesis Correlates with Histologic Subtype of Non–Hodgkin's Lymphoma

PURPOSE

Tumor stromal microenvironment promotes neoplastic growth and angiogenesis. We have previously shown that recruitment of marrow-derived vascular endothelial growth factor receptor-1(+) (VEGFR-1(+)) proangiogenic hematopoietic progenitors contributes instructively and structurally to neoangiogenesis in mouse models. Here, we investigated whether stromal incorporation of CD68(+) hemangiogenic cells and alpha-smooth muscle actin(+) (alpha-SMA(+)) stromal cells correlates with neoangiogenesis and progression in human non-Hodgkin's lymphoma subtypes.

EXPERIMENTAL DESIGN

Spatial localizations of vascular and stromal cells expressing CD34, VEGFR-1, alpha-SMA, and CD68 were examined by immunohistochemistry in 42 cases of non-Hodgkin's lymphoma, including diffuse large B-cell lymphoma, Burkitt lymphoma, follicular lymphoma, and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), and compared with benign follicular hyperplasia.

RESULTS

Compared with indolent lymphomas, there was a profound increase in recruitment of CD68(+) cells and VEGFR-1(+) neovessels in aggressive subtypes (including those transformed from indolent subtypes), where CD68(+) cells were localized to the perivascular region of neovessels as well as the stromal compartment. The perivascular CD68(+) cells expressed VEGFR-1 and VEGF-A. In contrast, there was a diffuse increase in alpha-SMA incorporation throughout the stromal compartment of indolent subtype of CLL/SLL compared with the scant perivascular pattern in aggressive subtypes. Overall, there was no correlation between CD34(+) microvessel density and lymphoma histologic subtype.

CONCLUSIONS

Heightened stromal hemangiogenesis as marked by infiltration of proangiogenic VEGFR-1(+)CD68(+)VEGF-A(+) cells and their paracrine cross-talk with neovasculature appears to be a distinct feature of aggressive lymphoma, providing novel targets for antiangiogenic therapy, whereas alpha-SMA(+) stromal vascular network may be differentially targeted in CLL/SLL.

Antitumor efficacy of a combination of CMC-544 (inotuzumab ozogamicin), a CD22-targeted cytotoxic immunoconjugate of calicheamicin, and rituximab against non-Hodgkin's B-cell lymphoma

PURPOSE

CMC-544 is a CD22-targeted cytotoxic immunoconjugate, currently being evaluated in B-cell non-Hodgkin's lymphoma (B-NHL) patients. Rituximab is a CD20-targeted antibody commonly used in B-NHL therapy. Here, we describe antitumor efficacy of a combination of CMC-544 and rituximab against B-cell lymphoma (BCL) in preclinical models.

EXPERIMENTAL DESIGN

BCLs were cultured in vitro with CMC-544, rituximab, or their combination. BCLs were injected either s.c. or i.v. to establish localized s.c. BCL in nude mice or disseminated BCL in severe combined immunodeficient mice, respectively. I.p. treatment with CMC-544 or rituximab was initiated at various times either alone or in combination and its effect on s.c. BCL growth or survival of mice with disseminated BCL was monitored.

RESULTS

In vitro growth-inhibitory activity of CMC-544 combined with rituximab was additive. Rituximab but not CMC-544 exhibited effector functions, such as antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Rituximab was less effective in inhibiting growth of established BCL xenografts than developing xenografts. In contrast, CMC-544 was equally effective against both developing and established BCL xenografts. Although CMC-544 and rituximab individually caused partial inhibition of the growth of BCL xenografts at suboptimal doses examined, their combination suppressed xenograft growth by >90%. In a disseminated BCL model, 60% of CMC-544-treated mice and 20% of rituximab-treated mice survived for 125 days. In contrast, 90% of mice treated with the combination of CMC-544 and rituximab survived for longer than 125 days.

CONCLUSION

The demonstration of superior antitumor activity of a combination of CMC-544 and rituximab described here provides the preclinical basis for its clinical evaluation as a treatment option for B-NHL.

Patterns of care in a population-based random sample of patients diagnosed with non-Hodgkin's lymphoma

New therapies have enhanced treatment of non-Hodgkin's lymphoma (NHL), but extent of treatment use in community practice is unknown. We conducted a population-based study of NHL patients diagnosed in 1999 with histologically confirmed NHL (n = 947) residing in areas covered by the Surveillance, Epidemiology, and End Results program. We performed analyses to study factors associated with receipt of chemotherapy, radiation, and rituximab, and examine factors associated with mortality. Most patients presented with B-cell lymphoma (n = 828). Approximately 20% of patients received no therapy, over 60% received chemotherapy, and 12% received rituximab, alone or in combination. Patients aged 75 +, and males were less likely to have received chemotherapy (p = 0.01). There were no significant associations between receipt of rituximab and the factors analyzed. Patients who presented with B-symptoms or unknown B-symptom status were less likely to receive radiation (OR = 0.32 and 0.47, respectively, p = 0.0002) than asymptomatic patients. Cause-specific and all-cause mortality were significantly associated with patient age, race/ethnicity, gender, marital status, co-morbid conditions, and histological subgroup. Hispanic and African-Americans, patients age 75 +, males, unmarried patients, or patients with B-symptoms had higher risk of death from NHL and all-cause (p < 0.01). This is the first population-based study examining therapy received for many histological subtypes of NHL.

Potent and specific antitumor efficacy of CMC-544, a CD22-targeted immunoconjugate of calicheamicin, against systemically disseminated B-cell lymphoma

PURPOSE

CMC-544 is a CD22-targeted immunoconjugate of calicheamicin and exerts a potent cytotoxic effect against CD22+ B-cell lymphoma. This study evaluated antitumor efficacy of CMC-544 against systemically disseminated B-cell lymphoma.

EXPERIMENTAL DESIGN

Scid mice received i.v. injections of CD22+ Ramos B-cell lymphoma cells for their systemic dissemination. CMC-544, G5/44, CD33-targeted CMA-676 (control conjugate) or rituximab were given i.p. 3, 9, 15, or 21 days after B-cell lymphoma dissemination. Diseased mice were monitored daily for hind-limb paralysis and death. Histopathological examination of CMC-544-treated and vehicle-treated diseased mice was also performed.

RESULTS

Mice with disseminated B-cell lymphoma developed hind-limb paralysis within 35 days. When given up to 15 days after B-cell lymphoma dissemination, CMC-544 extended survival of the diseased mice to >100 days, and these mice were considered cured. CMC-544 was efficacious when given during both the early initiation phase and the late established phase of the disease. A single dose of CMC-544 was effective in delaying the occurrence of hind-limb paralysis. In contrast, neither CMA-676 nor unconjugated G5/44 was effective. Rituximab was effective when given early in the disease process but not when the disease was established. Histopathological analysis revealed B-cell lymphoma infiltration in brain, spinal cord, bone marrow, and kidney in vehicle-treated but not in CMC-544-treated diseased mice. Consistent with its efficacy against the disseminated B-cell lymphoma, CMC-544 also caused regression of established Ramos B-cell lymphoma xenografts in scid mice.

CONCLUSIONS

CMC-544 confers strong therapeutic activity against systemic disseminated B-cell lymphoma and protects mice from hind-limb paralysis and death. These results support clinical evaluation of CMC-544 in the treatment of CD22+ lymphoid malignancies.

An uncommon clinical presentation of retroperitoneal non-Hodgkin lymphoma successfully treated with chemotherapy: A case report

We report the case of a patient affected by an extra-nodal non-Hodgkin lymphoma presenting as a unique, large retroperitoneal mass with an unusual clinical presentation mimicking gastric peptic or neoplastic disease. The patient was successfully treated with a first generation therapy, CHOP modified regimen (cyclophosphamide 600 mg/m² intravenously on d 1, epirubicin 55 mg/m² intravenously on d 1, vincristine 1.2 mg/m² intravenously on d 1, prednisone 60 mg/m² on d 1-5), and a complete response was achieved. The (18)F-fluorodeoxyglucose positron emission tomography was used to assess the therapy outcome. A brief review of literature is provided.

Long-term results of the R-CHOP study in the treatment of elderly patients with diffuse large B-cell lymphoma: a study by the Groupe d'Etude des Lymphomes de l'Adulte

PURPOSE

To analyze the long-term outcome of patients included in the Lymphome Non Hodgkinien study 98-5 (LNH98-5) comparing cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) to rituximab plus CHOP (R-CHOP) in elderly patients with diffuse large B-cell lymphoma.

PATIENTS AND METHODS

LNH98-5 was a randomized study that included 399 previously untreated patients, age 60 to 80 years, with diffuse large B-cell lymphoma. Patients received eight cycles of classical CHOP (cyclophosphamide 750 mg/m(2), doxorubicin 50 mg/m(2), vincristine 1.4 mg/m(2), and prednisone 40 mg/m(2) for 5 days) every 3 weeks. In R-CHOP, rituximab 375 mg/m(2) was administered the same day as CHOP. Survivals were analyzed using the intent-to-treat principle.

RESULTS

Median follow-up is 5 years at present. Event-free survival, progression-free survival, disease-free survival, and overall survival remain statistically significant in favor of the combination of R-CHOP (P = .00002, P < .00001, P < .00031, and P < .0073, respectively, in the log-rank test). Patients with low-risk or high-risk lymphoma according to the age-adjusted International Prognostic Index have longer survivals if treated with the combination. No long-term toxicity appeared to be associated with the R-CHOP combination.

CONCLUSION

Using the combination of R-CHOP leads to significant improvement of the outcome of elderly patients with diffuse large B-cell lymphoma, with significant survival benefit maintained during a 5-year follow-up. This combination should become the standard for treating these patients.

Combined chemotherapy with carmustine, doxorubicin, etoposide, vincristine, and cyclophosphamide plus mitoxantrone, cytarabine and methotrexate with citrovorum factor for the treatment of aggressive non-Hodgkin lymphoma

BACKGROUND

The standard treatment for patients with aggressive non-Hodgkin lymphoma (NHL) is cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Since 1989, the authors have used a new chemotherapy regimen with combined carmustine, doxorubicin, etoposide, vincristine, and cyclophosphamide plus mitoxantrone, cytarabine and methotrexate with citrovorum factor called BAVEC-MiMA. The objective of the current study was to explore, after a long follow-up period, the impact of this third-generation regimen for the treatment of aggressive NHL.

METHODS

One hundred and one consecutive patients (median age, 41 years) with either B-cell (n=94 patients) or non-B-cell (n=7 patients), aggressive lymphoma were diagnosed and treated between 1989 and 1999 with the BAVEC-MiMA regimen.

RESULTS

The complete response rate was 74%, and the overall response rate was 89%. Eleven patients with refractory disease died rapidly after a median period of 5 months. The major toxicity was Grade 4 neutropenia (according to World Health Organization criteria), which was observed in 15 patients (15%). There were four toxicity-related deaths. The overall survival rate was 63% at 9 years. In multivariate analysis, factors that were associated with advantage in overall survival were response to induction therapy, bulky disease, and high score on the International Prognostic Index (IPI). The disease-free survival rate was 77% at 9 years. In multivariate analysis, the IPI was the most important variable for the definition of disease-free survival.

CONCLUSIONS

The BAVEC-MiMA regimen was feasible on an outpatient basis, it was tolerated well, and it showed a low toxicity-related mortality. The long follow-up in patients with NHL, which is a rapidly fatal disease, led the authors to observe that, with this regimen, a cure was obtained in > 50% of patients who had low-risk or low-to-intermediate-risk, aggressive NHL.

Antibody-targeted therapy: a paradigm of innovative treatment strategies in indolent and aggressive B-cell non-Hodgkin lymphoma

PURPOSE OF REVIEW

This review outlines the principles of treatment of indolent and aggressive B-cell lymphoma based on current knowledge on the classification of hematologic malignancies and the rationale to implement new antibody-targeted immunotherapeutic approaches.

RECENT FINDINGS

An update is provided on the use of antibody-targeted therapies in clinical trials, with emphasis on new, emerging strategies of immunotherapy in B-cell non-Hodgkin lymphoma.

SUMMARY

The success of immune-mediated therapies has encouraged studies on antibody-targeted therapy in B-cell non-Hodgkin lymphoma. Promising new approaches combine classical dose-intense chemotherapy with "tumor-specific" antibody targeting during several phases of the disease. The safety and efficacy of anti-CD20 in the treatment of indolent and aggressive B-cell non-Hodgkin lymphoma at any stage of disease, either as a single agent or as part of multimodality regimes, as an unconjugated antibody or as radioimmunoconjugate have changed dramatically our treatment strategies. Increasing insights into basic molecular biology and immunology of B-cell non-Hodgkin lymphoma may identify subgroups of patients categorized in current classification systems who may benefit from tailored approaches with new modality antibody-targeted therapy in near future.