Treatment outcomes for older patients with relapsed/refractory aggressive lymphoma receiving salvage chemotherapy and autologous stem cell transplantation are similar to younger patients: a subgroup analysis from the phase III CCTG LY.12 trial.

Background: High-dose therapy and autologous stem cell transplantation (ASCT) is often considered for older patients (age >60 years) with relapsed/refractory aggressive lymphomas. Although registry data support the safety and potential efficacy of this approach, there are no prospective trials evaluating outcomes of ASCT in older patients. We evaluated the result of second-line chemotherapy and ASCT in older versus younger patients in the CCTG randomized LY.12 trial. Patients and methods: From August 2003 to November 2011, 619 patients with relapsed/refractory aggressive lymphoma were randomized to gemcitabine, dexamethasone, cisplatin (GDP) or dexamethasone, cytarabine, cisplatin (DHAP); 177 patients (28.6%) enrolled were >60.0 years of age (range, 60-74) and 442 were ≤60.0 years of age. After two to three cycles, responding patients proceeded to ASCT. Intention-to-treat analysis was used to compare response rate, transplantation rate, event-free survival (EFS) and overall survival (OS) between patients aged ≤60.0 and >60.0 years. Results: Patient characteristics were comparable between the two cohorts, except a larger proportion of older patients had high International Prognostic Index risk scores. Response to salvage therapy was 48.6% for patients aged >60.0 versus 43.0% for those aged ≤60.0 (P = 0.21). Transplantation rates were also similar: 50.3% versus 49.8% (P = 0.87) for older versus younger patients. Rates of febrile neutropenia and adverse events requiring hospitalization were comparable for older and younger patients (30.5% versus 22.9% and 37.9% versus 32.1%, respectively). With a median follow-up of 53 months, there was no difference in 4-year OS (36% and 40% for patients aged >60.0 and ≤60.0 years, P = 0.42), or 4-year EFS (20% versus 28%, P = 0.43). Mortality from salvage therapy was 8/174 (4.60%) and 5/436 (1.15%), and 100-day mortality post-ASCT was 7/88 (8.06%) and 4/219 (1.85%). Conclusion: This subgroup analysis suggests that older patients derive similar benefit from salvage therapy and ASCT to younger patients, with acceptable toxicity. ClinicalTrials.gov Identifier: NCT00078949.

Prolonged clinical remissions in patients with relapsed or refractory follicular lymphoma treated with autologous stem cell transplantation incorporating rituximab.

Three sequential phase II trials were conducted with different immunotherapy approaches to enhance the outcome of autologous transplant (high-dose therapy and autologous stem cell transplantation (HDT/ASCT)) for recurrent follicular lymphoma. Seventy-three patients were enrolled from 1996 to 2009. Patients received HDT/ASCT combined with (1) interferon-α 3 MU/m(2) subcutaneously (SC) three times per week (TIW) for 2 years post-ASCT, (2) rituximab (R) 375 mg/m(2) for in vivo purging 3-5 days pre-stem cell collection and 2 × 4 weekly R at 2 and 6 months post-ASCT, respectively, or (3) three infusions of R pre-stem cell collection followed by 6× R weekly and interferon-α 3 MU/m(2) SC TIW. Although not statistically significant, progression-free survival (PFS) for patients who received rituximab was 56.4 and 49.1% at 5 and 10 years compared to 36 and 21% in those who did not receive rituximab. Molecular relapse post-HDT/ASCT was the strongest predictor of PFS in a multivariate analysis. Molecular relapse was coincident with or preceded clinical relapses in 84% of patients who relapsed­median of 12 months (range 0-129 months). Adverse events included secondary malignancy, transformation to diffuse large B cell lymphoma, prolonged mostly asymptomatic hypogammaglobulinemia, and pulmonary fibrosis. The long-term toxicity profile must be considered when selecting patients for this treatment.

Prognostic value of the trichorhinophalangeal syndrome-1 (TRPS-1), a GATA family transcription factor, in early-stage breast cancer.

BACKGROUND: TRPS-1 is a new GATA transcription factor that is differentially expressed in breast cancer (BC) where it been found recently to regulate epithelial-to-mesenchymal transition (EMT). PATIENTS AND METHODS: We carried out a quantitative immunohistochemistry (qIHC) analysis of TRPS-1 expression in 341 primary-stage I-III BC samples in relation to patient clinical characteristics as well as its prognostic value, especially in an estrogen receptor-positive (ER+) subgroup. RESULTS: Higher TRPS-1 expression was significantly associated with a number of clinical and pathological characteristics as well as with improved overall survival (OS) and disease-free survival (DFS). Among stage I/II ER+ BC patients who received endocrine therapy alone, those with high TRPS-1 expression had significantly longer OS and DFS. There was also a strong association between TRPS-1 levels and the EMT marker E-cadherin in the ER+ invasive ductal carcinoma cases. Analysis of gene expression data on a panel of BC lines found that TRPS-1 expression was low or absent in BC lines having enriched mesenchymal features. CONCLUSIONS: Our data indicated that TRPS-1 is an independent prognostic marker in early-stage BC and a new EMT marker that can distinguish patients with ER+ BC who will respond longer to adjuvant endocrine therapy.

Review of Bruton tyrosine kinase inhibitors for the treatment of relapsed or refractory mantle cell lymphoma.

Mantle cell lymphoma (mcl) is a rare subtype of aggressive B-cell non-Hodgkin lymphoma that remains incurable with standard therapy. Patients typically require multiple lines of therapy, and those with relapsed or refractory (r/r) disease have a very poor prognosis. The Bruton tyrosine kinase (btk) inhibitor ibrutinib has proven to be an effective agent for patients with r/r mcl. Although usually well tolerated, ibrutinib can be associated with unique toxicities, requiring discontinuation in some patients. Effective and well-tolerated alternatives to ibrutinib for patients with r/r mcl are therefore needed. Novel btk inhibitors such as acalabrutinib, zanubrutinib, and tirabrutinib are designed to improve on the safety and efficacy of first-generation btk inhibitors such as ibrutinib. Data from single-arm clinical trials suggest that, compared with ibrutinib, second-generation btk inhibitors have comparable efficacy and might have a more favourable toxicity profile. Those newer btk inhibitors might therefore provide a viable treatment option for patients with r/r mcl.

Human lymphoblastoid cell lines expressing mutant p53 exhibit decreased sensitivity to cisplatin-induced cytotoxicity.

Human lymphoblastoid cells were transfected with expression vectors containing p53 cDNA mutated at either codon 135 or 246. The cells were subjected to cisplatin treatment or gamma-radiation and observed for changes in the cell cycle arrest and apoptosis. We found that compared to the parental cell line, cells overexpressing mutant p53 (either 246val or 135ser) exhibited decreased apoptosis in response to gamma-radiation or cisplatin as measured by: propidium iodide (PI) staining of the cellular DNA (cell cycle analysis) and decrease in PARP (poly ADP-ribose polymerase) cleavage as detected by Western blotting. Interestingly the cells expressing mutant p53(135ser) protein were less resistant to cisplatin-induced apoptosis than the p53(246val)-bearing cell line. A significant decrease in the G1/S arrest assayed by bromodeoxyuridine and PI staining (cell cycle/proliferation assay) was also observed in response to irradiation and cisplatin in cell lines expressing either of the mutant p53 constructs. A lower basal level and reduced magnitude of protein induction of the cell cycle inhibitor p21/Waf1 was seen both after cisplatin and gamma-radiation treatment in the mutant p53 expressing lymphoblastoid variant when compared to the wild type p53 parental cell line but induction of the p53 regulator MDM2 was comparable in both. No increase in basal levels of Bc12 protein in wild type or mutant p53 expressing cells was observed in response to cisplatin or irradiation. Unexpectedly, following cisplatin treatment we observed an increase in mutant and wild type p53 RNA steady state levels in addition to increased levels of p53 protein. These results suggest that irradiation or cisplatin treatment may not only stabilize wild type p53 protein but also may increase the steady state p53 RNA levels. Finally these results indicate that both irradiation and cisplatin should be used with caution in the treatment of lymphoid tumors bearing mutations of p53.

Comparison of CMV, RSV, SV40 viral and Vlambda1 cellular promoters in B and T lymphoid and non-lymphoid cell lines.

Determining the activity of viral and cellular regulatory elements in B or T lymphoid cell lines would facilitate appropriate utilization of the regulatory sequences for gene transfer- and expression-dependent applications. We have compared the activity of the CMV, RSV and SV40 viral promoter/enhancers as well as the Vlambda1 cellular promoter, in three B cell lines (REH, SMS-SB, C3P), three T cell lines (CEM, Jurkat, ST-F10), and two non-lymphoid cell lines (K-562, HeLa) using the luciferase reporter gene. In B cell lines, the activity of the CMV promoter/enhancer construct was the highest ranging from 10- to 113-fold greater than that of SV40. In contrast, in T cell lines the RSV promoter/enhancer activity was 11-65-fold higher than that of SV40. The Vlambda1 promoter activity was close to that of SV40 promoter/enhancer in most of the cell lines tested. We conclude that CMV and RSV promoter/enhancers contain stronger regulatory elements than do the SV40 and Vlambda1 for expression of genes in lymphoid cell lines.

Significance of a partial or slow response to front-line chemotherapy in the management of intermediate-grade or high-grade non-Hodgkin's lymphoma: a literature review.

PURPOSE: The purpose of this review was to assess the outcome of patients with non-Hodgkin's lymphoma (NHL) who achieve an incomplete or slow response to front-line chemotherapy and to determine whether salvage treatment with intensive combination chemotherapy with or without autologous bone marrow transplantation (ABMT) is successful in such patients. METHODS: A comprehensive literature search of studies using combination chemotherapy for the front-line therapy of advanced-stage intermediate- and high-grade NHL and for salvage therapy of patients with a partial response (PR) was reviewed. RESULTS: The median survival duration of patients with a PR ranged between 5 to 14 months, while the median survival duration of patients with a complete response (CR) was not reached in many studies. For patients in CR, the probability of survival at 24 months ranged between 0.79 to 1, while for patients in PR it ranged from 0 to 0.31. The rapidity of a response to front-line therapy was often found to be of prognostic importance. Patients who relapsed after a PR to front-line therapy had similar outcomes to intensive salvage therapy as those who relapsed after a CR. ABMT performed immediately after a PR to induction therapy, before progressive disease occurred, resulted in high CR rates in nonrandomized studies. CONCLUSION: Patients with aggressive NHL who experience a PR or who respond slowly to front-line chemotherapy have a poor prognosis. Early introduction of dose-intensive salvage therapy before the development of progressive disease may benefit patients with a PR and requires testing in randomized clinical trials.

Detection of occult lymphoma in the peripheral blood and bone marrow of patients with untreated early-stage and advanced-stage follicular lymphoma.

PURPOSE: The object of this study was to compare the relative sensitivities of morphologic, immunophenotypic, gene rearrangement, cytogenetic, and polymerase chain reaction (PCR) analyses in the detection of lymphoma cells in the bone marrow and peripheral blood of patients with follicular lymphoma. PATIENTS AND METHODS: Bone marrow and peripheral-blood samples from 28 newly diagnosed patients with follicular lymphoma referred from several different medical centers were assessed. Routine morphologic assessment was performed initially and the remainder of the sample was aliquoted for DNA extraction to be used for gene rearrangement and PCR analyses and for immunophenotypic and cytogenetic analyses where a sufficient amount of sample remained. RESULTS: Morphologic assessment of the bone marrow was positive for lymphoma cells in 11 of 28 patients. PCR amplification of t(14;18) breakpoint DNA detected lymphoma cells in 17 of 24 patients assessed. Morphologic assessment detected lymphoma cells in three bone marrow samples that were negative by PCR. PCR analysis was the only method able to detect circulating lymphoma cells in peripheral blood at diagnosis and was positive in 15 of 24 samples. The other methods of assessment did not show lymphoma in any samples in which lymphoma was not detected by morphologic or PCR analysis. Lymphoma cells were found in the bone marrow and/or peripheral blood as frequently in early-stage patients as in advanced-stage patients. CONCLUSION: PCR amplification of t(14;18) breakpoint DNA together with morphologic assessment had the highest yield of detecting lymphoma cells in the bone marrow and/or peripheral blood of our population of newly diagnosed patients with follicular lymphoma. The clinical significance and prognostic importance of lymphoma cells detected by PCR in the bone marrow and/or peripheral blood of newly diagnosed follicular lymphoma patients awaits long-term follow-up data of these and additional patients.

Sensitive and reproducible detection of occult disease in patients with follicular lymphoma by PCR amplification of t(14;18) both pre- and post-treatment.

The t(14;18) chromosomal translocation occurs in most follicular non-Hodgkin's lymphomas and places the Bcl-2 gene on chromosome 18q21 into the immunoglobulin JH region on chromosome 14q32. This translocation can be exploited to detect clonal malignant cells bearing this genetic alteration. A polymerase chain reaction (PCR) assay amplifying over the major breakpoint region (mbr) and minor cluster region (mcr) was developed and optimized. In this report, the sensitivity and reproducibility of this semiquantitative assay, performed on a relatively large number of clinical samples is shown. A titration curve of DNA made from a t(14;18)- cell line admixed with increasing ratios of a t(14;18)+ cell line was used to demonstrate that one t(14;18)+ cell in 100,000 t(14;18)- cells could reproducibly be detected. Occult lymphoma cells, not detected by standard morphologic analysis, were demonstrated in almost two-thirds of the bone marrow and peripheral blood specimens obtained from untreated patients with follicular lymphoma. Of 11 bone marrow samples assessed, seven were positive for occult disease by PCR amplification over the mbr and one was positive over the mcr. Of these six positive marrow samples, only three had been reported positive by standard morphologic criteria. In addition, seven of nine peripheral blood samples assessed were positive over the mbr and one additional sample was positive over the mcr. None of these were morphologically positive. Seven of the above patients would have been upstaged if these results were utilized for staging, including two of three patients with stage I or stage II disease. PCR-detectable occult disease persisted in four of four patients assessed both pre- and post-treatment, even after aggressive multi-drug combination chemotherapy in two of these patients. The clinical significance of detecting this occult disease must await the study of larger numbers of patients and the clinical outcomes of patients with occult disease and patients without occult disease.

Sequence preservation of the third exon of the bcl-2 gene in non-Hodgkin's lymphoma: absence of somatic hypermutation.

The t(14;18) translocation juxtaposes the bcl-2 gene on chromosome 18 to a joining (J) gene segment of the immunoglobulin heavy chain gene (IgH) on chromosome 14. Up to 85% of non-Hodgkin's lymphomas (NHL) are t(14;18) positive. Recent reports have documented point mutations in the second exon of translocated bcl-2 alleles and postulated that immunoglobulin variable (V) region somatic hypermutation, related to Ig sequences approximately 250 Kb downstream, may be mediating these mutations. We have examined the third exon of bcl-2, directly adjacent to Ig sequences in the t(14;18), for point mutations. In particular, we studied the translated region of exon 3 in 45 NHLs by SSCP analysis and failed to detect a single point mutation. Further, we sequenced eleven t(14;18) breakpoints, including both bcl-2 and JH sequences, and detected only one point mutation, in a JH-derived sequence. We conclude that immunoglobulin V region somatic hypermutation does not induce point mutations into the t(14;18) breakpoint region or into the translated region of the third exon of bcl-2 alleles involved in the t(14;18) translocation, conserving the membrane insertion properties of the carboxyl tail of this protein.

Functional analysis of the human RAG 2 promoter.

Recombination activating genes RAG1 and RAG2 are essential components of V(D)J recombination, a process that generates the specific antigen receptors in lymphocytes. To understand the mechanisms underlying the lineage and developmental regulation of transcription of RAG2, we have characterized the human RAG2 exon 1A promoter. In this study, a series of deletion constructs were used to isolate the promoter while a linker scanning approach was taken to assess functionally relevant cis elements within the promoter. Two regulatory domains were identified. The -140 to -123 region is critical for promoter activity in all cell lines tested. Mutations to the putative Ets (-122 to -118) or to the C/EBP (-137 to -129) consensus core sequences did abrogate promoter activity, although specific DNA/protein interactions remained, as determined by EMSA. The -69 to -48 region demonstrates lineage specific promoter activity. Mutations to an overlapping, BSAP-myb-Ikaros-myb site (-65 to -39) resulted in differential promoter activity in human B and T cells. EMSA analysis of this region showed a B cell specific protein complex. Transfection of BSAP into cell lines trans-activates the human RAG2 promoter. We conclude that transcriptional regulation of the human RAG2 gene is complex, involving both tissue specific and ubiquitous factors, and both proximal and distal regulatory elements.

Immunogenicity of whole-cell tumor preparations infected with the ALVAC viral vector.

The immunogenicity of recombinant canarypox (ALVAC) viral vectors within murine whole-cell tumor vaccines was evaluated using the T cell thymic lymphoma STF10 and the B16 melanoma. Tumor cells were modified with the recombinant ALVAC vectors and injected into syngeneic mice. Control mice receiving cells alone all developed tumors, while mice injected with tumor variants bearing parental and recombinant vectors either completely rejected their tumors, or exhibited a significant delay in tumor formation. Rechallenge of mice receiving STF10-variant vaccines yielded a protective effect against parental tumor cells only when a modified regimen incorporating two vaccinations was utilized. Notably, the parental ALVAC virus was equivalent to all other recombinant ALVAC viruses in conferring antitumor immunity when using a prime-and-boost protocol. Tumorigenicity experiments in nude mice revealed that the effector mechanism mediating rejection of tumor cells bearing ALVAC vectors is multifactorial, in that the immunogenicity of STF10/ALVAC vaccines is reduced, but not completely abolished in these mice. Finally, in vitro experiments revealed that cytotoxic T cells specific for parental STF10 cells could be generated as a result of in vivo immunization with STF10/ALVAC vaccines.

Enhanced immunogenicity of B cell lymphoma genetically engineered to express both B7-1 and interleukin-12.

The A20 murine B cell lymphoma was transfected with B7-1 and subsequently these variants and vector control variants were retrovirally infected to express murine interleukin-12 (mIL-12). In vitro data showed that the B7-1 variants enhanced secretion of IL-2 and IL-4 by allogeneic T cells in mixed lymphocyte tumor cultures. While IL-12 variants stimulated IFN-gamma, variants expressing both B7-1 and IL-12 stimulated IFN-gamma, IL-2, and IL-4 secretion. Tumorigenicity experiments showed that whereas B7-1 delayed tumor onset, only the mIL-12 variants with or without B7-1 were completely rejected in syngeneic hosts. In addition, tumor-free mice were protected against subsequent challenge with the parental unmodified cells and had enhanced cytotoxic T lymphocyte (CTL) lysis activity. Results from minimal disease mixing experiments demonstrated that only the A20/B7-1/mIL-12 variant was able to reject A20 unmodified cells inoculated at the same site, whereas prolonged survival was observed when the A20 parental cells were inoculated at different sites. Depletion studies and injections into nu-/nu- mice demonstrated that both CD4+ and CD8+ T cells may mediate immunity. These data suggest that vaccinations with tumor cells genetically modified to express both B7-1 and IL-12 may alter cytokine profiles and generate CTL activity and, thus, the mechanisms of enhanced antitumor immunity may be multifactorial.

Molecular diagnostics in follicular non-Hodgkin's lymphoma: a review.

Follicular lymphoma is a low-grade, indolent non-Hodgkin's lymphoma characterized by the presence of the t(14;18) translocation. The detection of this translocation using polymerase chain reaction techniques has been increasingly studied. However, the diagnostic and prognostic value of detecting t(14;18) rearrangements has been questioned. Translocation has been identified in a significant proportion of healthy donors and patients with nonmalignant diseases. Clearance of t(14;18) rearrangements following conventional treatments, purging of bone marrow/peripheral blood stem cells, and transplantation is associated with improved long-term outcome of patients with follicular lymphoma. Until randomized studies confirm the clinical utility of polymerase chain reaction detection of the translocation, emphasis should be placed on improving the accuracy and reproducibility of polymerase chain reaction techniques, and standardizing assays among laboratories.

Stem cell function and engraftment is not affected by "in vivo purging" with rituximab for autologous stem cell treatment for patients with low-grade non-Hodgkin's lymphoma.

The chimeric anti-CD20 monoclonal antibody rituximab (Rituxan; IDEC Pharmaceuticals, San Diego, CA, and Genentech, Inc, San Francisco, CA) has recently been approved by the US Food and Drug Administration as single-agent treatment of relapsed/refractory low-grade or follicular non-Hodgkin's lymphoma. Initial results from the pivotal clinical trial revealed that response rates to rituximab were higher in patients who previously had high-dose therapy and autologous stem cell transplantation. We have initiated a clinical trial that combines the use of rituximab with high-dose chemotherapy followed by autologous stem cell transplantation for patients with chemosensitive relapsed follicular small cleaved or mantle cell lymphoma. A unique feature of this study is that in addition to eight maintenance infusions of rituximab after autologous stem cell transplantation, patients also received rituximab 375 mg/m2 2 days before a granulocyte colony-stimulating factor-mobilized stem cell collection as "in vivo purge." We report on preliminary results demonstrating the safety and efficacy of the in vivo purge on 10 patients undergoing stem cell mobilization, nine of whom have already undergone transplantation. The peripheral blood CD34+ counts were 14.92 and 20 x 10(6)/L on day 4 and day 5, respectively, of the stem cell mobilization with granulocyte colony-stimulating factor. This compares with 11.7 and 11.8 x 10(6)/L, respectively, for the control population. The median CD34 stem cell yield in the graft collection was 3.7 x 10(6)/kg in patients receiving rituximab in vivo purge compared with 3.1 x 10(6)/kg in the control population. The target stem cell collection was successfully collected in six of 10 patients in a 1-day single large-volume leukapheresis collection, while two patients required 2 days and the last two patients required 3 days. Functional assays revealed the stem cell colony-forming unit-granulocyte monocyte and burst-forming unit-erythrocyte to be 55 and 44 colonies per plate, respectively, for the patients receiving the in vivo rituximab purge. This compares favorably with 37 and 38.5 colonies per plate, respectively, for the control population. Neutrophil engraftment took a median of 11 days for both cohorts; platelet independence was achieved in 8 days compared with 10 days for the control population. The median number of platelet transfusions was two for patients receiving rituximab and 2.5 for the control group. Assessment of serum cytokines immediately before the rituximab infusion during the stem cell mobilization and immediately after revealed a twofold to sevenfold increase in interleukin-1beta, tumor necrosis factor-alpha, and interleukin-6. The polymerase chain reaction analysis for minimal residual disease in stem cell collections and in peripheral blood and bone marrow samples of these patients will help to determine the efficacy of rituximab in vivo purge on disease progression.

Bcl-2 clearance: optimising outcomes in follicular non-Hodgkin's lymphoma.

The long median survival time of patients with follicular non-Hodgkin's lymphoma (NHL), means that the efficacy of new treatments are difficult to assess in the short term. Bcl-2 is an inhibitor of apoptosis and overexpression of the bcl-2 gene in the blood or bone marrow is a feature in up to 85% of patients with follicular NHL. Levels of bcl-2(+) cells in the peripheral blood or bone marrow therefore are a useful measure of disease status in such patients and can be detected by polymerase chain reaction (PCR). Complete bcl-2 clearance from the bone marrow (molecular remission) following autologous stem cell transplant (ASCT) for follicular NHL is considered to be an important prognostic factor for disease-free survival. Tumour cell contamination of the stem cell grafts used in ASCT is commonly associated with relapse. This can be addressed by purging the stem cell harvest prior to transplantation. Various methods of in vitro purging after stem cell collection have been shown to reduce the level of contamination but yield is invariably reduced and grafts remain bcl-2 positive. However, in vivo purging with rituximab during the process of collection has been used to obtain bcl-2-negative stem cell harvests without compromising the yield. Rituximab is a monoclonal antibody licensed for treatment of relapsed and refractory low-grade or follicular NHL. Rituximab targets the CD20 antigen, which is found on cells of the B cell lineage. When used for in vivo purging it depletes the peripheral blood of CD20-positive cells and prevents contamination by lymphoma cells. Molecular remission, as measured by bone-marrow bcl-2 clearance, has been achieved in 7/7 patients with follicular NHL at 1 year after treatment with ASCT using rituximab as an 'in vivopurse', followed by rituximab maintenance. Early clinical outcomes are also encouraging.

Immunoglobulin somatic variation; studies of receptor editing in a human B cell lymphoma.

In order to study mechanisms of immunoglobulin somatic variation in committed immunoglobulin (Ig) expressing B cells, we used the fluorescent activated cell sorter to isolate rare variants from a surface Ig positive (sIg+) diffuse large cell B lymphoma cell line (mu lambda+). These variants were either negative for sIg expression (sIg-) or expressed sIg which differed from the original parental tumor cell line, both in idiotypes and Ig lambda isotypes (sIg+Id-). In the following report we review the results from the studies of these variants. DNA analysis showed that all variants had new Ig lambda gene rearrangements, which had occurred either on a previously excluded allele, or on the productively rearranged allele of the parental cell line. The sIg- variants, which had undergone nonfunctional Ig lambda rearrangements on the expressed parental allele, and thereby deleted the productive rearrangement, continued to functionally rearrange the same allele and regenerated sIg expression. While the parental cell line expressed low levels of the recombination activating genes, RAG1 and RAG2, expression of these genes were considerably upregulated in both the immunoglobulin negative and the idiotypic variants. Somatic immunoglobulin V gene hypermutation did not contribute to the observed immunoglobulin somatic variation. These results demonstrate that, through differential expression of the RAG genes, sIg+ B cells are able to somatically alter their sIg receptors through secondary Ig lambda gene rearrangements. This mechanism may allow B cells with non-selectable, or auto-reactive, antigen receptors to alter these receptors (receptor editing). Ongoing Ig gene rearrangement may limit the usefulness of immunotherapeutic approaches directed at the antigen receptor in some diffuse large cell lymphomas.

Delivery of full dose CHOP chemotherapy to elderly patients with aggressive non-Hodgkin's lymphoma without G-CSF support.

Because of evidence that failure to deliver full dose CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) may compromise the outcome of elderly patients with aggressive non-Hodgkin's lymphoma (NHL), we attempted to deliver full dose CHOP to these patients. The objective of this review was to assess the relative received dose intensity (ARRDI), toxicity and outcome of elderly patients treated with curative intent with CHOP at our centre. Charts were reviewed of all patients > or = 65 years with newly diagnosed aggressive NHL referred to the Toronto-Sunnybrook Regional Cancer Centre (TSRCC) for initial management from 1990-1995 before routine use of G-CSF. Sixty eligible patients were identified. 31 received CHOP +/- radiation (XRT), 9 other curative treatment and 20, palliative treatment. The mean ARRDI calculated on 29/31 patients receiving CHOP was .86; 41%=1.0, 24%=.90-.99, 14%=.75-.89 and 21%=<.75. During 141 cycles of CHOP. 17 (12%) episodes of febrile neutropenia (FN) occurred in 14 (45%) patients and other grade 3/4 toxicity occurred in <10% of patients. There were 3 (10%) toxic deaths. Sixteen (52%) patients required a total of 29 admissions to hospital for FN (59%) or other causes. Of the 31 patients, 16 (52%) achieved a complete remission (CR), 7 (23%) a partial remission-1 (PR-1), 2 (6%) a partial remission-2 (PR-2), 1 (3%) had no response (NR), 2 (6%) had progressive disease and 3 (10%) were not evaluable (NE). The median progression free survival (PFS) and overall survival (OS) were (16+) months and (24.5) months respectively. We found that physician biases resulted in the selection of; younger patients (median 71 vs. 80 years), patients with a better ECOG performance status (> or =2, 13% vs. 50%) and patients with less co-morbid illness (42% vs. 90%) for attempt at curative treatment with CHOP chemotherapy. Age was never the sole reason for offering palliative treatment. In conclusion, a subset of patients over the age of 65 with aggressive NHL, who have a good performance status and minimal co-morbid illness can tolerate full dose CHOP chemotherapy without G-CSF support. Future strategies should emphasize full dose treatment with curative intent with minimization of both hematologic and non-hematologic toxicity. Clinical studies are required to determine whether routine G-CSF support will reduce toxicity or improve outcome in this group of patients.

Immunosuppressive toxicity of CAMPATH1H monoclonal antibody in the treatment of patients with recurrent low grade lymphoma.

We have studied, as part of a group of international multicenter phase II clinical trials, the toxicity and effectiveness of CAMPATH1H administered intravenously three times a week in an outpatient setting to patients with recurrent or progressive low grade lymphoma. We report here on the toxicity and therapeutic results of the first seven patients treated before the study was closed prematurely because of unacceptable toxicity. Classical complete or partial responses of treatment were seen in three of seven patients. One complete response lasted 8.5 months and the other complete response is ongoing at 1 year. Responses occurred in nodal sites as well as in skin and peripheral blood. The first three or four antibody infusions in each patient was associated with grade 1 or 2 side-effects including rigor, fever, facial flushing, nausea, vomiting, hives, wheezes, hypotension, and/or diarrhea but these subsequently decreased or disappeared. The most significant toxicity was profound lymphopenia and associated infection, usually viral. Six of seven patients had culture or serologically documented infections and four patients had two or more such episodes. All infections responded to temporary discontinuation of antibody therapy and appropriate antiviral or antibiotic agents. We conclude that CAMPATH1H monoclonal antibody has therapeutic activity against low grade non-Hodgkin's lymphoma but that this activity is limited by marked lymphopenia and an unacceptably high frequency of serious infection at the dose and schedule used in this trial.

Mitoxantrone-DHAP with GM-CSF: an active but myelosuppressive salvage therapy for relapsed/refractory aggressive non-Hodgkin's lymphoma.

This study was designed to evaluate the efficacy and toxicity of dose intensifying DHAP (dexamethasone, cytarabine and cisplatin) salvage chemotherapy by adding mitoxantrone with GM-GSF support in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL). From March 1992 to January 1995, 22 patients with intermediate and high grade (aggressive) NHL refractory or relapsed after adriamycin containing chemotherapy regimens were treated with M-DHAP+GM-CSF, (dexamethasone 40 mg i.v. days 1-4, cisplatin 100 mg/m2 i.v. by continuous infusion over 24 hours on day 1, cytarabine 2 gm/m2, i.v. every 12 hours for 2 doses on day 2, mitoxantrone 10 mg/m2 i.v. on days 3 and 4 and GM-CSF 250-500 microg/m2 s.c. daily beginning day 5 until absolute neutrophil count recovery. Most patients had poor prognostic factors including primary refractory disease (18/22), bulky disease (12/22), elevated LDH (9/22), or bone marrow involvement (8/22). All 22 patients were evaluable. The overall response rate was 41% (CR 23% and PR 18%). There were three toxic deaths, all related to sepsis. Median progression free survival (PFS) and overall survival (OS) rates were 5.2 months and 11.8 months respectively. At the same time of the analysis two patients were alive after high-dose therapy and bone marrow transplant at 34 and 36 months follow-up and two were alive with disease. The maximal acceptable dosage of mitoxantrone was 10 mg/m2 x 2 due to serious hematologic toxicity. Treatment delays and dose reductions compromised delivering the optimal dose intensity of M-DHAP. A poor prognostic group of patients with refractory or recurrent aggressive lymphoma, many of whom were not eligible for high-dose therapy and stem cell transplantation were treated with repeated cycles of dose intensified DHAP with growth factor support. Although M-DHAP had therapeutic activity even in patients considered to have primary refractory disease, myelosuppression was dose limiting and frequently limited the number of cycles. Therefore, if M-DHAP is to be further evaluated, therapeutic results may be improved further by incorporating strategies to reduce myelotoxicity such as the use of growth factors to reduce platelet transfusion requirements or the use of autologous stem cell support after each cycle.