Comparing the ability of freshly generated and cryopreserved dendritic cell vaccines to inhibit growth of breast cancer in a mouse model

Repetitive vaccinations with dendritic cell (DC)-based vaccines over long periods of time can break pre-existing tolerance to tumors and achieve clinically relevant immune response. This requires a large number of DCs to be generated under good manufacturing protocol, which is time- and cost intensive. Thus, producing a large numbers of DCs at one time point and cryopreserving these cells in ready-for-use aliquots for clinical application may overcome this constraint. This could also reduce batch-to-batch variations. In this study, we generated DCs from bone marrow obtained from BALB/c mice. Some of the generated DCs were cryopreserved before conducting various tests. There were no significant differences in the morphology and phenotype between cryopreserved and freshly generated DCs. Both types of DCs pulsed with tumor lysate (TL) from 4T1 murine mammary cancer cells (DC+TL) possessed a similar capacity to stimulate the proliferation of T-cells. In addition, cryopreserved and fresh DC pulsed with TL showed similar tumor growth inhibition patterns. Both DCs induced initial retardation of tumor growth (p<0.05) and prolonged the survival (p<0.05) of tumor-bearing mice treated with DC+TL as compared with nontreated control mice. Cryopreserved DCs shared similar therapeutic efficacy to fresh DCs, and this finding lends supports the routine use of cryopreserved DCs in future clinical trials.

Prognostic factors in low-grade non-Hodgkin lymphomas

Low-grade non-Hodgkin lymphomas were once considered as a heterogenous group of lymphomas characterized by an indolent clinical course. Today, low-grade non-Hodgkin lymphomas are classified as a group of 10 distinct entities, each characterized by unique clinico biologic features. Follicular lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytic lymphoma, and marginal zone lymphoma are the most-investigated subtypes. Several studies have been performed to identify prognostic factors specific for each subtype in an effort to help clinicians in treatment decisions. The field of biologically specific associated parameters holds great potential but requires more research and work to produce translational results.

The role of rituximab in autologous and allogeneic hematopoietic stem cell transplantation for non-Hodgkin's lymphoma

The addition of rituximab to chemotherapy has substantially changed the treatment strategies for patients with B-cell lymphomas. Rituximab, combined with standard chemotherapy regimens, shows consistently improved results compared with chemotherapy alone and has been extensively employed in both newly diagnosed and relapsed patients with B-cell lymphoma. Because of its low toxicity profile and its potent antilymphoma activity mediated through direct apoptotic and indirect effector mechanisms, rituximab also has been actively incorporated into stem cell transplantation (SCT) protocols to attain a state of minimal disease, provide a safe and effective method for in vivo purging prior to autologous SCT, and promote graft-versus-lymphoma effects in allogeneic SCT. This review compiles the still immature but rapidly growing data on this combined modality.

Rituximab added to first-line mitoxantrone, chlorambucil, and prednisolone chemotherapy followed by interferon maintenance prolongs survival in patients with advanced follicular lymphoma: an East German Study Group Hematology and Oncology Study

PURPOSE

Rituximab has been shown to be active in follicular lymphoma (FL), both as monotherapy and in combination with chemotherapy. We conducted a randomized trial comparing mitoxantrone, chlorambucil, and prednisolone (MCP) chemotherapy plus rituximab with MCP alone.

PATIENTS AND METHODS

Previously untreated patients with stage III or IV CD20+ indolent or mantle cell lymphoma were randomly assigned to either eight 28-day cycles of MCP plus rituximab (R-MCP; n = 181) or eight cycles of MCP alone (n = 177). All patients who achieved a complete or partial remission were treated with interferon maintenance until relapse. Herein, we report the results from the primary analysis population of patients with FL, who constituted the majority of patients (56%) recruited to the trial (n = 201; R-MCP, n = 105; MCP, n = 96).

RESULTS

Rates of overall and complete response were significantly higher in the R-MCP arm than the MCP arm (overall response, 92% v 75%, respectively; P = .0009; complete response, 50% v 25%, respectively; P = .004). With a median follow-up time of 47 months, median event-free survival (EFS) and progression-free survival (PFS) times were significantly prolonged with R-MCP compared with MCP (EFS, not reached v 26 months, respectively; P < .0001; PFS, not reached v 28.8 months, respectively; P < .0001), and overall survival (OS) was significantly improved with R-MCP compared with MCP (4-year OS rate, 87% v 74%, respectively; P = .0096).

CONCLUSION

The R-MCP regimen significantly improves complete and overall response rates, EFS, PFS, and OS in patients with previously untreated advanced FL, without a clinically significant increase in toxicity.

Prognosis of follicular lymphomas

Follicular lymphoma (FL) is as an indolent neoplasia with median survival measured in decades. Nevertheless, some patients have poor progression-free survival and overall survival. Several treatment approaches are proposed for patients with FL, however criteria to rationalize treatment decisions are lacking. Studies have been performed to build up prognostic indices that are useful for defining risk-adapted treatment recommendations. Available indices are based on parameters that have an independent role in predicting patient survival and that are variably correlated with the features of the disease, with the characteristics of the patient and with the effects of treatment. Two new prognostic indices have recently been proposed for FL: the Italian Lymphoma Intergroup (ILI) index and the Follicular Lymphoma International prognostic Index (FLIPI). Both indices are based on large series of patients and exhibit differences in their ability to discriminate between patients with different probabilities of survival. In recent years, with the advent of gene expression profile studies, our knowledge of the biology of FL is changing as novel data become available about the lymphoma cell and about the role of the microenvironment; these studies have already provided novel prognostic tools for identifying patients with more aggressive disease. Further data and large international cooperative studies are needed to translate into clinical practice the novel acquisitions of biology and therapeutics.

Purine Analogue Combinations for Indolent Lymphomas

Indolent lymphomas are a group of lymphoid malignancies with differing patterns of behavior and responses to treatment. The progress in treating patients with hairy cell leukemia (HCL) using nucleoside analogues can be used as a model for other indolent B-lymphoproliferative disorders, such as follicular lymphoma. Recent advancements in therapeutic options available for these patients include combination therapy with agents that have differing mechanisms of action and non-overlapping toxicity. It has been shown that patients who are candidates for aggressive therapy might receive benefit, including disease-free survival and overall survival, from combination purine analogue therapy. Using these more aggressive therapeutic approaches earlier in the disease course and as maintenance therapy may further enhance outcomes. With the advent of these new therapies along with the molecular evaluation of these regimens, we may be nearing the time where the goal for more advanced indolent lymphoma will be to achieve a cure.

Follicular lymphoma in early stages: high risk of relapse and usefulness of the Follicular Lymphoma International Prognostic Index to predict the outcome of patients

BACKGROUND AND OBJECTIVES

Patients with follicular lymphoma (FL) in advanced stages are currently deemed incurable with standard treatments. However, FL is considered to be eradicable in the small group of patients presenting with localized disease. The objective of this study was to analyze the clinical features and the outcome of a series of patients with FL in early stages with a long follow-up.

PATIENTS AND METHODS

A total of 48 patients (25m/23f; median age: 50 yr) diagnosed consecutively with FL in Ann Arbor stage I (25 cases) or II (23) at a single institution with a median follow-up of 9.5 yr were included in the study. Main biological and clinical characteristics at diagnosis, including Follicular Lymphoma International Prognostic Index (FLIPI) were analyzed; treatment and response were assessed and analyzed for prognosis.

RESULTS

The histologic subtypes were: FL type I, 20 cases (42%); type II, 24 (50%); type III, three (6%); and unclassifiable, one (2%). Distribution according to FLIPI was: low risk (36 cases) and intermediate risk (five cases). Treatment mainly consisted of combination chemotherapy (CHOP in 34 cases) plus involved-field radiotherapy in 26 cases. Forty patients (89%) achieved a complete response (CR), three (7%) a partial response, and two (4%) were non-responders; the remaining three patients did not receive therapy. No initial variable predicted CR achievement. About 57% of the patients in CR eventually relapsed with a relapse risk of 46% at 10 yr. Intermediate-risk FLIPI predicted failure-free survival. Histologic transformation was observed in six patients with a 10-yr risk of transformation of 13%. Twelve patients died during follow-up, in two cases as a result of unrelated causes. Overall survival (OS) at 10 yr was 79%. The FLIPI was the sole variable predicting OS.

CONCLUSIONS

Although the majority of patients with localized FL achieve CR, the risk of relapse is high. The FLIPI is of prognostic value in these patients.

Modelling intervention effects after cancer relapses

This article addresses the problem of incorporating information regarding the effects of treatments or interventions into models for repeated cancer relapses. In contrast to many existing models, our approach permits the impact of interventions to differ after each relapse. We adopt the general model for recurrent events proposed by Peña and Hollander, in which the effect of interventions is represented by an effective age process acting on the baseline hazard rate function. To accommodate the situation of cancer relapse, we propose an effective age function that encodes three possible therapeutic responses: complete remission, partial remission, and null response. The proposed model also incorporates the effect of covariates, the impact of previous relapses, and heterogeneity among individuals. We use our model to analyse the times to relapse for 63 patients with a particular subtype of indolent lymphoma and compare the results to those obtained using existing methods.

Follicular lymphoma: time for a re-think?

Follicular lymphoma (FL) is a malignancy of follicle centre B cells that have at least a partially follicular pattern, and is the commonest type of indolent Non-Hodgkin's lymphoma. Except in the subset of patients with localized disease, FL should still be regarded as an incurable malignancy with a relentless relapsing/remitting course. However, the provocative new data covered by this review (including anti-CD20 antibody therapy, BCL-2, radioimmunotherapy, new chemotherapeutic agents and anti-idiotype vaccination), provides much cause for excitement and guarded optimism. Rituximab represents a novel treatment approach for a variety of disease settings, with a proven excellent efficacy and toxicity profile. Long-term data is required to establish whether its use translates into survival benefit. As the clinical activity of rituximab and other new therapeutic approaches becomes established, it will be important to determine how best to integrate these results into the standard care of patients with follicular lymphoma.

Quantitative Assessment of Disease Involvement by Follicular Lymphoma Using Real-Time Polymerase Chain Reaction Measurement of t(14;18)-Carrying Cells

Chromosomal translocation t(14:18)(q32;q21) is one of the most common karyotypic abnormalities in non-Hodgkin's lymphomas. It occurs in more than 85% of follicular lymphoma (FL) cases. Real-time polymerase chain reaction (Q-Rt-PCR) analysis using double-labeled fluorogenic probes is a new tool in the detection and quantification of t(14;18)-carrying cells. We analyzed 239 specimens with Q-Rt-PCR to detect and quantify t(14;18)-carrying cells. To investigate the clinical usefulness of the quantitative assessment, we analyzed the clinical correlation with 92 FL patients of varying clinical status. Of 59 previously untreated patients, patients with stage IV disease had significantly higher quantities of t(14;18)-carrying cells measurable in the bone marrow or the peripheral blood than patients in clinical stages I to III (P = .003 and .043, respectively). Moreover, of the 33 posttherapy patients. the patients in complete remission appeared to have lower detectable levels of t(14;18)-carrying cells than patients in partial remission or with recurrent disease. Q-Rt-PCR permits a sensitive and quantitative assessment of the extent of disease involvement in patients with t(14;18)-carrying FL. The technique has the potential to be a useful tool in the diagnosis of FL, disease assessment, and prognosticating patients' clinical outcomes.

Mitoxantrone-cyclophosphamide-rituximab: an effective and safe combination for indolent NHL

Treatment for extensive indolent lymphoma should combine optimization of efficacy without excessive toxicity. Rituxan may be an ideal agent for combinations with chemotherapy because of its non-cross-resistant toxicity profile and the potential for synergism. We present the results of 32 patients with indolent B-cell NHL who received a novel three-drug combination designed with the intent of preservation of both efficacy and quality of life. Patient characteristics were as follows, median age, 58 years (36-75 years); histology, follicular 16, SLL/CLL five, lymphoplasmacytic six, marginal cell five; relapsed or refractory, 10; untreated, 22. Patients first received cyclophosphamide 800 mg/m(2) and mitoxantrone 8 mg/m(2), iv on the same day, every 3 weeks for two cycles. Subsequently, patients received rituximab followed by mitoxantrone 8 mg/m(2) every 2 weeks for four cycles. The regimen, and particularly rituximab, was extremely well tolerated. Grade I/II, infusion-related toxicity was noted in 10%. Six patients achieved a PR and 23 a CR for an overall response of 90% (95% CI: 79-100%). The actuarial median TTP for all patients was 30 months. Molecular remissions were noted in 8/14 patients tested in CR. We conclude that the cyclophosphamide-mitoxantrone-rituxan (CyMiR) regimen is effective and extremely well tolerated. Furthermore, rituximab infusion-related morbidity is nearly completely eliminated.

Molecular remission and non-Hodgkin's lymphoma

Non-Hodgkin's lymphomas are highly sensitive to treatment and complete clinical responses are often achieved. However, disease recurrence is common and is caused by the persistence of malignant lymphoma cells at a level below the limits of detection by conventional assessment such as clinical examination, bone marrow morphology and CT scans. This minimal residual disease can be detected using molecular techniques such as the polymerase chain reaction (PCR), and treatments capable of eliminating minimal residual disease are described as producing molecular remission. Molecular assessment is now commonly used as a measure of outcome in clinical trials of novel therapies for the treatment of lymphoma. The evidence for using molecular remission as a surrogate marker of clinical response in this setting is reviewed and the significance of minimal residual disease in determining prognosis and planning treatment strategies is addressed.

Quantitative real-time polymerase chain reaction for detection of circulating cells with t(14;18) in volunteer blood donors and patients with follicular lymphoma

The chromosomal rearrangement t(14;18)(q32;21) involves the major (MBR) or minor (mcr) breakpoint cluster regions and the immunoglobulin heavy chain joining regions (JH) in most follicular lymphomas. As a first step towards determining the clinical significance of circulating cells with t(14;18), we detected and quantitated circulating cells in samples obtained from volunteer blood donors and follicular lymphoma patients. The t(14;18) was co-amplified with beta-actin with real-time quantitative PCR (QRT-PCR) in reactions containing 1 microg of DNA from peripheral blood or bone marrow aspirates. The cell number was quantitated using linear regression and an external standard of serially diluted DNA from cell lines with MBR/JH or mcr/JH rearrangements. At dilutions of 10(5) and 106, sensitivity was 100 and 55% for MBR/JH, and 100 and 10% for mcr/JH rearrangements. Among 102 volunteer blood donors MBR/JH vs. mcr/JH amplicons were detected in 22 vs. 4% with duplicate 1 microg DNA reactions, and in 41 vs. 6% with a total 10 microg DNA analyzed in multiple reactions. Among volunteer blood donors the mean number of circulating cells with MBR/JH vs. mcr/JH rearrangements were 0.8 vs. 0.1/microg DNA, and exceeded the upper normal limit (defined as the mean of all volunteer samples plus two standard deviations) in 3% vs. 2%, respectively. Analysis for MBR/JH rearrangements revealed that follicular lymphoma patients vs. volunteer blood donors were positive in 76% vs. 22% (p = 0.008 by Fisher's exact test); that the mean number of MBR/JH cells per microg of DNA was 91 vs. 0.8 (p = 0.0002 by Mann-Whitney test); and the number of the MBR/JH cells exceeded the upper normal limit in 32% vs. 3% of subjects (p = 0.0001 by Fisher's exact test). Circulating cells with mcr/JH were not detected among any of these 25 lymphoma patients. We conclude that patients with follicular lymphoma are more frequently positive, have higher numbers of circulating cells with t(14;18), which exceed upper normal limit more frequently than in volunteer blood donors.

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.

A randomized controlled trial to evaluate the role of interferon as initial and maintenance therapy in patients with follicular lymphoma

The purpose of this study was to evaluate the role of interferon as initial and maintenance therapy in patients with newly diagnosed follicular lymphoma. Between 1984 and 1994, 204 patients with newly diagnosed Stage III or Stage IV follicular lymphoma were randomized to receive either, Chlorambucil (CB): 10 mg daily for 6 weeks, followed by a 2-week interval, with 3 subsequent 2-week treatment periods at the same dose, separated by 2-week intervals, or, CB given concurrently with interferon (IFN). IFN was given at a dose of 3 x 10(6)units thrice weekly, subcutaneously, throughout the 18-week treatment period. Responding patients were subsequently randomized to receive maintenance IFN at the dose and schedule described above, or to expectant management. The overall response rate was 161/204 (78%), complete remission being achieved in 24% of patients. Neither the addition of IFN to the initial treatment, nor the use of maintenance IFN influenced response rate, remission duration or survival. This study was undertaken to determine whether IFN, given in combination with, and then subsequent to, CB would alter the clinical course of patients with follicular lymphoma. Disappointingly, this objective was not achieved, no advantage having been demonstrated for the addition of IFN.