MicroRNA-125b as a valuable predictive marker for outcome after autologous hematopoietic stem cell transplantation

BACKGROUND

Relapse is a frequent occurrence in autologous hematopoietic stem cell transplantation (AHSCT), and early relapse after AHSCT results in poor survival and low quality of life. Predictive marker determination for AHSCT outcomes could be helpful in the prevention of relapse through personalized medicine. Here the predictive value of circulatory microRNAs (miRs) expression for AHSCT outcomes was studied.

METHODS

50 MM and lymphoma candidates for AHSCT participated in this study. Two plasma samples were obtained before AHSCT from each candidate; one before mobilization and the other after conditioning. Extracellular vesicles (EVs) were isolated by ultracentrifugation. miR-125b, miR-126, miR-150, and miR-155 expression were analyzed in both plasma and EVs using real time polymerase chain reaction analysis. Other data related to AHSCT and its outcomes were also collected. The predictive value of miRs and other factors for outcomes was assessed by multi-variant analysis.

RESULTS

By 90 weeks follow up after AHSCT, multi-variant and ROC analysis showed miR-125b as a predictive marker for relapse, high lactate dehydrogenase (LDH), and high erythrocyte sedimentation rate (ESR). The cumulative incidence of relapse, high LDH, and high ESR increased with an increase in circulatory miR-125b expression.

CONCLUSION

miR-125b could be applicable in prognosis evaluation and also create a possible new targeted therapy opportunity for enhanced outcomes and survival after AHSCT.

TRIAL REGISTRATION

The study was retrospectively registered. Ethic code No: IR.UMSHA.REC.1400.541.

Nanomedicine as a magic bullet for combating lymphoma

Hematological malignancy like lymphoma originates in lymph tissues and has a propensity to spread across other organs. Managing such tumors is challenging as conventional strategies like surgery and local treatment are not plausible options and there are high chances of relapse. The advent of novel targeted therapies and antibody-mediated treatments has proven revolutionary in the management of these tumors. Although these therapies have an added advantage of specificity in comparison to the traditional chemotherapy approach, such treatment alternatives suffer from the occurrence of drug resistance and dose-related toxicities. In past decades, nanomedicine has emerged as an excellent surrogate to increase the bioavailability of therapeutic moieties along with a reduction in toxicities of highly cytotoxic drugs. Nanotherapeutics achieve targeted delivery of the therapeutic agents into the malignant cells and also have the ability to carry genes and therapeutic proteins to the desired sites. Furthermore, nanomedicine has an edge in rendering personalized medicine as one type of lymphoma is pathologically different from others. In this review, we have highlighted various applications of nanotechnology-based delivery systems based on lipidic, polymeric and inorganic nanomaterials that address different targets for effectively tackling lymphomas. Moreover, we have discussed recent advances and therapies available exclusively for managing this malignancy.

Long-term outcome in patients with follicular lymphoma following high-dose therapy and autologous stem cell transplantation

OBJECTIVE

To contribute data on long-term outcome and potential curative impact of ASCT in FL, especially following HDT with the BEAM protocol (BCNU, etoposide, cytarabine and melphalan), given very limited data on this topic in the literature.

PATIENTS AND METHODS

Patients with FL (n = 76) were treated in our institution with HDT and ASCT. In the case of long-term remission (≥8 years), peripheral blood was tested for minimal residual disease by t(14;18)- and IGH-PCR, including the last follow-up.

RESULTS

10-year overall survival, progression-free survival, and freedom from progression (FFP) after first-line ASCT (n = 20) were 80%, 60%, and 69%, after second-line ASCT (n = 48, following BEAM) 66%, 38%, and 41%, after third/fourth-line ASCT (n = 8) 33%, 25%, and 25%, respectively. Prognostic factors for FFP were treatment line and FLIPI (Follicular Lymphoma International Prognostic Index). 10-year FFP for second-line ASCT and low-risk FLIPI at relapse was 69%, intermediate-risk 28%, and high-risk 25% (P < .05). 26 patients developed sustained long-term clinical and molecular remissions of up to 27 years.

CONCLUSIONS

Sustained long-term clinical and molecular complete remissions up to 27 years can be achieved following ASCT (including HDT with BEAM in second treatment line), indicating a potential curative impact of ASCT in FL.

Durable benefit of rituximab maintenance post-autograft in patients with relapsed follicular lymphoma: 12-year follow-up of the EBMT lymphoma working party Lym1 trial

We report the 12-year follow-up of the prospective randomized EBMT LYM1 trial to determine whether the benefit of brief duration rituximab maintenance (RM) on progression-free survival (PFS) in patients with relapsed follicular lymphoma (FL) receiving an autologous stem cell transplant (ASCT) is sustained. One hundred and thirty-eight patients received RM with or without purging. The median follow-up after random assignment is 12 years (range 10-13) for the whole series. The 10-year PFS after ASCT is 47% (95% CI 40-54) with only 4 patients relapsing after 7.5 years. RM continues to significantly improve 10-year PFS after ASCT in comparison with NM [P = 0.002; HR 0.548 (95% CI 0.38-0.80)]. Ten-year non-relapse mortality (NRM) was not significantly different between treatment groups (7% overall). 10-year overall survival (OS) after ASCT was 75% (69-81) for the whole series, with no significant differences according to treatment sub-groups. 10-year OS for patients who progressed within 24 months (POD24T) was 60%, in comparison with 85% for patients without progression. Thus the benefit of rituximab maintenance after ASCT on relapse prevention is sustained at 12 years, suggesting that RM adds to ASCT-mediated disease eradication and may enhance the curative potential of ASCT.

Cellular Therapy in Follicular Lymphoma: Autologous Stem Cell Transplantation, Allogeneic Stem Cell Transplantation, and Chimeric Antigen Receptor T-cell Therapy

A subset of follicular lymphoma patients with high-risk clinical features continues to pose a therapeutic challenge. Hematopoietic stem cell transplantation is a suitable consolidative treatment option for these patients. Data on chimeric antigen receptor T-cell therapy are promising in relapsed/refractory and transformed patients. The increasing armamentarium of nontransplant options coupled with the associated potential long-term sequelae of transplantation raises questions about the placement of transplant strategies in the follicular lymphoma treatment hierarchy.

Clinical characteristics and outcomes of relapsed follicular lymphoma after autologous stem cell transplantation in the rituximab era

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a therapeutic option for patients with relapsed follicular lymphoma (FL). The clinical characteristics and outcomes of FL relapse after ASCT in the rituximab era have not yet been fully elucidated. We retrospectively reviewed 414 FL patients treated with ASCT between 2000 and 2014 in four hematology departments. All patients received rituximab as a first-line treatment. We specifically analyzed the clinical characteristics, treatment strategies at relapse, and outcomes of 95 patients (23%) who relapsed after ASCT. The patients (median age, 57 y) received a median of two lines of therapy (range, 2-6) prior to ASCT, with 92% in complete response (CR) or partial response (PR) before ASCT. Histological transformation at relapse after ASCT was observed in 20% of the patients. Treatment at relapse after ASCT consisted of chemotherapy with or without rituximab (n = 45/90, 50%), targeted agents (18%), rituximab monotherapy (14%), or consolidation allogeneic transplantation after induction chemotherapy (12%) and radiotherapy (6%). After relapse, the median progression-free survival (PFS) and overall survival (OS) were 1 year (95% CI, 0.541-1.579) and 5.5 years (95% CI, 1.910-9.099), respectively. In the multivariate analysis, histological transformation (HT) was associated with OS (P = .044; HR 2.439; 95% CI, 1.025-5.806), and a high FLIPI score at relapse was associated with PFS (P = .028; HR 2.469; 95% CI, 1.104-5.521). This retrospective study showed that the period of PFS of patients who relapsed after ASCT is short. A biopsy should be performed for these patients to document the HT. Our results indicate that new treatment strategies will need to be developed for these patients.

Follicular lymphoma: Update on management and emerging therapies at the dawn of the new decade

Follicular lymphoma is the most common indolent non-Hodgkin lymphoma. Survival has improved over the last several decades, mainly because of the incorporation of the anti-CD20 antibody rituximab into preexisting or rediscovered agents. The disease has a relapsing and remitting pattern, coupled with a risk of transformation into an aggressive lymphoma, and considered incurable for most patients. Next-generation sequencing technologies have increased our understanding of the biology and genetic landscape of the disease, identifying potential druggable targets for treatment. Current prognostic models cannot accurately identify patients at risk of early progression and despite the availability of treatment options for relapsed/refractory disease, rational treatment selection balancing disease control, efficacy with toxicity, and quality of life remain unmet needs. This review provides an overview of biology, prognostication, treatment options, and emerging therapies that provide valid grounds for optimism.

Strategies to improve outcomes of autologous hematopoietic cell transplant in lymphoma

High-dose chemotherapy and autologous hematopoietic cell transplantation (HDT-AHCT) remains an effective therapy in lymphoma. Over the past several decades, HDT with BEAM (carmustine, etoposide, cytarabine, and melphalan) and CBV (cyclophosphamide, carmustine, and etoposide) have been the most frequently used preparatory regimens for AHCT in Hodgkin (HL) and non-Hodgkin lymphoma (NHL). This article reviews alternative combination conditioning regimens, as well as novel transplant strategies that have been developed, to reduce transplant-related toxicity while maintaining or improving efficacy. These data demonstrate that incorporation of maintenance therapy posttransplant might be the best way to improve outcomes.

Progression-free survival at 2 years post-autologous transplant: a surrogate end point for overall survival in follicular lymphoma

Overall survival (OS) is the gold‐standard end point for studies evaluating autologous stem cell transplantation (ASCT) in follicular lymphoma (FL), but assessment may be elusive due to the lengthy disease course. We analyzed the validity of two earlier end points, proposed in the setting of first‐line chemo‐/immunotherapy, as surrogates for OS—progression‐free survival (PFS) status at 24 months (PFS24) and complete response at 30 months (CR30) post‐ASCT. We also have investigated the clinical features of patients with early progression after ASCT. Data were available for 626 chemosensitive FL patients who received ASCT between 1989 and 2007. Median follow‐up was 12.2 years from ASCT. In the PFS24 analysis, 153 (24%) patients progressed within 24 months and 447 were alive and progression‐free at 24 months post‐ASCT (26 who died without disease progressions within 24 months were excluded). Early progression was associated with shorter OS (hazard ratio [HR], 6.8; P = 0.00001). In the subgroup of patients who received an ASCT in the setting or relapse after being exposed to rituximab, the HR was 11.3 (95% CI, 3.9–30.2; P < 0.00001). In the CR30 analysis, 183 of 596 (31%) response‐evaluable patients progressed/died with 30 months post‐ASCT. The absence of CR30 was associated with shorter OS (HR, 7.8; P < 0.00001), including in patients with prior rituximab (HR, 8.2). PFS24 and CR30 post‐ASCT are associated with poor outcomes and should be primary end points. Further research is needed to identify this population to be offered alternative treatments.

Current prognostic and predictive factors in follicular lymphoma

Follicular lymphoma (FL) is generally considered an indolent disorder. With modern day treatments, long remissions are often achieved both in the front-line and relapsed setting. However, a subset of patients has a more aggressive course and a worse outcome. Their identification is the main purpose of modern day prognostic tools. In this review, we attempt to summarize the evidence concerning prognostic and predictive factors in FL, including (1) pre-treatment factors, from baseline clinical characteristics and imaging tests to histological grade, the microenvironment and genomic abnormalities; (2) post-treatment factors, i.e., depth of response, measured both by imaging tests and minimal residual disease; (3) factors at relapse and duration of response; and (4) prognostic factors in histological transformation. We conclude that, despite the existence of numerous tools, the availability of some of them is still limited; they generally suffer from notable downsides, and most have unproven predictive value, thus having scarce bearing on the choice of regimen at present. However, with the technological and scientific developments of the last few years, the potential for these prognostic factors is promising, particularly in combination, which will probably, in time, help guide therapeutic decisions.

[Follicular lymphoma. High-dose immunochemotherapy with autologous blood stem cell transplantation: Results of the first prospective study in Russia]

AIM

to evaluate the efficiency of high-dose chemotherapy (HDCT) with further autologous blood stem cell transplantation (auto-BSCT) in the first-line therapy of patients with follicular lymphoma (FL) and poor prognostic factors.

SUBJECTS AND METHODS

In 2000 to 2015, the National Research Center for Hematology, Ministry of Health of the Russian Federation, performed therapy in 39 patients with FL and poor prognostic factors (a total of 215 patients with FL). The R-CHOP treatment was done as induction therapy. Sequential HCT and further auto-BSCT were performed in 29 (74%) of the 39 patients, who had shown a partial tumor response to the induction therapy or achieved partial remission after 4-6 cycles of CT, but had poor prognostic factors. 22 of the 29 patients underwent auto-BSCT in first-line therapy after induction R-CHOP regimens. Among them, there were 17 men with a median age of 46 years (31-68 years). 21 of the 22 patients were recorded to have Stage IV by the Ann Arbor staging classification. Bulky peritoneal and retroperitoneal tumors larger than 7 cm were detectable at disease onset in 14 of the 22 cases. Two patients were noted to have phenomena of leukemization. 16 patients had bone marrow (BM) involvement. According to the Follicular Lymphoma International Prognostic Index-1 (FLIPI-1), the patients were divided into 3 groups: 1) a low risk (n=5); 2) an intermediate risk (n=3); a high risk (n=14). B-symptoms were observed in 16 cases. 16 patients were diagnosed with cytological grade I-II FL and 6 had grade IIIA. According to the tumor proliferative pattern, the distribution turned out to be as follows: nodular (n=6), nodular-diffuse (n=13), and diffuse (n=3). The proliferative activity index averaged 30% (8-90%). Serum and urine proteins were immmunochemically assayed in 18 cases, out of them 8 patients were diagnosed as having serum β2-microglobulin concentrations above normal as a poor prognostic factor. In 14 of the 22 patients, the activity of lactate dehydrogenase was greater than normal (266-7806 U/l).

RESULTS

Out of the 22 patients, 20 who have undergone auto-BSCT in first-line therapy are survivors and have remission of the underlying disease: 18 and 2 patients achieved complete and partial remission, respectively. The follow-up period was 7 to 178 months (median, 32 months). After auto-BSCT in the first remission, 2 patients developed disease recurrences: an early recurrence after 9 months in one case and a late recurrence 6 years after completion of therapy in the other.

CONCLUSION

The first prospective study of intensive therapy for FL in Russia has demonstrated that HDCT with further auto-BSCT in first-line therapy allows complete remission in patients with poor prognostic factors and higher overall and progression-free survival rates.

Reappraising the timing of transplant for indolent non-Hodgkin lymphomas

INTRODUCTION

Indolent non-Hodgkin lymphomas (iNHL) remain incurable with standard approaches. The timing of autologous stem cell transplant (ASCT) is changing following the introduction of new drugs that can potentially defer the transplant, improved reduced intensity conditioning (RIC) and haploidentical allogeneic SCT (allo-SCT).

AREAS COVERED

The most relevant aspects concerning the role of hematopoietic stem cell transplantation in the management of iNHL are discussed. Literature search methodology included examination of PubMed index and meeting presentations. Expert commentary: ASCT is not currently employed as consolidation in first-line, being reserved to patients with refractory/relapsed disease. The curative potential of graft-versus-lymphoma (GVL) after RIC allo-SCT could be particularly beneficial in patients with iNHL relapsing after ASCT. This scenario could be modified in the near future by better definition of high-risk patients at diagnosis, by the improvement of minimal residual disease (MRD) evaluation and by the introduction of new drugs in the therapeutic algorithm.

Reduced intensity allogeneic stem cell transplantation for follicular lymphoma relapsing after an autologous transplant achieves durable long-term disease control: an analysis from the Lymphoma Working Party of the EBMT†

BACKGROUND

Patients with follicular lymphoma (FL) relapsing after an autologous transplant (autoSCT) may be treated with a variety of therapies, including a reduced intensity allogeneic transplant (RICalloSCT). We conducted a retrospective analysis of a large cohort of patients undergoing RICalloSCT for FL in this setting.

PATIENTS AND METHODS

A total of 183 patients, median age 45 years (range 21-69), had undergone an autoSCT at a median of 30 months before the RICalloSCT. Before the RICalloSCT, they had received a median of four lines (range 3-10) of therapy and 81% of patients had chemosensitive disease and 16% had chemoresistant disease. Grafts were donated from sibling (47%) or unrelated donors (53%).

RESULTS

With a median follow-up of 59 months, the non-relapse mortality (NRM) was 27% at 2 years. The median remission duration post-autoSCT and RICalloSCT was 14 and 43 months, respectively. The 5-year relapse/progression rate, progression-free survival and overall survival were 16%, 48% and 51%, respectively, and were associated with age and disease status at RICalloSCT.

CONCLUSION

These data suggest that an RICalloSCT is an effective salvage strategy in patients with FL recurring after a prior autoSCT and might overcome the poor prognostic impact of early relapse after autoSCT.

The potential benefit of allogeneic over autologous transplantation in patients with very early relapsed and refractory follicular lymphoma with prior remission duration of ≤12 months

Early relapsed or refractory follicular lymphoma (FL) warrants consolidation with transplantation, though graft source modality remains controversial. We analysed the outcomes of 44 patients transplanted with either autologous or allogeneic graft sources in the post-rituximab era. No difference in event-free (EFS) or overall survival (OS) was observed between allogeneic (81% and 81%) and autologous transplantation (64% and 70%) at 3 years. There was a significant difference in EFS between allogeneic and autologous transplantation patients with previous remission duration of ≤12 months (80% and 42% at 3 years, P < 0·015). Very early relapsed FL may warrant consideration of allogeneic over autologous transplantation in the appropriate setting.

Rituximab for indolent lymphomas before and after allogeneic hematopoietic stem cell transplantation

PURPOSE OF REVIEW

The most substantial advancement in the treatment of indolent B-cell non-Hodgkin lymphoma (NHL), since the advent of combination chemotherapy, has been the introduction of the monoclonal anti-CD20 antibody rituximab. However, the optimal schedule, timing, and duration of rituximab therapy remain controversial.

RECENT FINDINGS

Since its initially reported single-agent activity in 1997, the role of rituximab has greatly expanded and it is now ubiquitously integrated in all treatment phases of indolent NHL. Yet, several questions remain to be addressed: should asymptomatic patients be treated at diagnosis with single-agent rituximab or still kept in watchful waiting, what are the optimal first-line treatments to combine with rituximab, what is the role of maintenance therapy, and is there a benefit in incorporating rituximab in autologous and allogeneic stem cell transplantation schemes for these diseases? Recent and ongoing clinical trials tackling these relevant issues will be presented and critically discussed in this article.

SUMMARY

Excellent outcomes are reported with rituximab therapy in indolent NHL, both early and late in the disease course. Continued study of this most valuable therapeutic agent is warranted to set the optimal treatment approach leading to cure the majority of patients.

High-dose chemotherapy followed by autologous and allogeneic hematopoietic stem cell transplantation in patients with follicular non-Hodgkin’s lymphoma in the rituximab era

High-dose chemotherapy in lymphomas, and mainly non-Hodgkin’s lymphomas, has been advancing since the 1970s. This therapeutic strategy is based on the supposed existence of a dose-response curve for cytotoxic agents. However, the available data are contradictory, so high-dose chemotherapy cannot be guaranteed as consolidation treatment for first-remission follicular lymphoma or diffuse large cell lymphoma. The objective of this paper is to review the current knowledge about high-dose chemotherapy followed by hematopoietic stem cell transplantation in follicular non-Hodgkin’s lymphoma. The published studies on follicular lymphoma after first remission, recurrent follicular lymphoma, and transformed follicular ­lymphoma were assessed together with the data available on diffuse large cell lymphoma. During analysis of the studies, difficulties were encountered in comparing studies due to the heterogeneous nature of the data. High-dose chemotherapy as consolidation treatment after first remission or in recurrent or refractory disease was also analyzed.

Autologous hematopoietic stem cell transplantation for relapsed follicular lymphoma: safety profile and clinical outcome in a single-center experience

Autologous hematopoietic stem cell transplantation (AHSCT) is a treatment option for relapsed and recurrent follicular lymphoma (R/R FL); however, its value in the rituximab era remains to be elucidated. To evaluate the safety and clinical outcome of AHSCT for relapsed FL, we present a retrospective series of AHSCT for 30 FL patients (17 male and 13 female) at median age of 49 years. Patients were transplanted in second or subsequent complete or partial response after at least one therapeutic line including chemotherapy and rituximab. Overall, seven patients achieved second or higher complete response (CR) at AHSCT, whereas 23 were transplanted in partial response. Median overall survival (OS) was not reached, whereas progression-free survival (PFS) was 4.8 years. The estimated 10-year OS and PFS were found to be 60 and 33%, respectively. There was no significant difference in OS and PFS in terms of FLIPI score and disease status at transplant. Median follow-ups from diagnosis and from AHSCT were 4.9 years (range 1.5-18.4 years) and 1.7 years (range 0.03-16.5 years), respectively. Fifteen patients relapsed, and 11 out of them (73%) died of disease recurrence and chemoresistance. At the last contact, 19 patients are alive: 12 are in CR, whereas seven patients receive salvage regimens due to active lymphoma. AHSCT for relapsed FL patients who were pretreated with rituximab remains a safe procedure with low transplant-related mortality and long-term progression-free survival in about one-third of transplanted patients.

Autologous stem cell transplantation for follicular lymphoma is of most benefit early in the disease course and can result in durable remissions, irrespective of prior rituximab exposure

The role of autologous stem cell transplantation (ASCT) and the optimal timing of such transplants in patients with follicular lymphoma (FL) remains contentious. We present a single-centre experience documenting the outcomes of 70 FL patients who underwent BEAM (carmustine, cytarabine, etopside, melphalan)-conditioned ASCT between 1988 and 2009. With a median follow-up of 6·8 years (0·1-19·2), the 7-year overall survival (OS) and progression-free survival (PFS) from the date of ASCT was 76% and 60%, respectively. A significant difference in OS was found when comparing the patients transplanted in first or second remission versus those transplanted in later remissions (P = 0·02) and this significance was maintained when OS was calculated from the date of diagnosis (P = 0·03). There was a plateau on the PFS curves for patients transplanted in either first or second remissions after 9·3 and 6·4 years respectively, suggesting that these groups may never relapse. No differences were seen in OS or PFS in those treated with rituximab prior to transplant versus those who were not. Our data shows that BEAM ASCT can be a highly effective treatment in patients with FL early in the disease course, and that a proportion of patients experience prolonged disease-free survival and may be cured.

Long term follow-up of BEAM-autologous and BEAM-alemtuzumab allogeneic stem cell transplantation in relapsed advanced stage follicular lymphoma

This is an analysis in 171 patients comparing BEAM-Auto and BEAM-Allo (alemtuzumab)-hematopoietic stem cell transplantation in relapsed follicular lymphoma. BEAM-Allo group had a lower 10 years cumulative incidence of relapse(31.4% vs 55.1%, p=0.042), a trend to a plateau in survival but no statistical differences in OS or DFS, and a TRM of 24%. When transplanted in CR BEAM-Allo patients had better OS and DFS. Incidence of acute and chronic GVHD was 16.6% and 22%. 29% of BEAM-Allo patients received DLI (all but two remain in CR and alive). Our data supports Allo-HSCT as a potential curative treatment for selected patients with FL.

Rituximab purging and/or maintenance in patients undergoing autologous transplantation for relapsed follicular lymphoma: a prospective randomized trial from the lymphoma working party of the European group for blood and marrow transplantation

PURPOSE

The objective of this randomized trial was to assess the efficacy and safety of rituximab as in vivo purging before transplantation and as maintenance treatment immediately after high-dose chemotherapy and autologous stem-cell transplantation (HDC-ASCT) in patients with relapsed follicular lymphoma (FL).

PATIENTS AND METHODS

Patients with relapsed FL who achieved either complete or very good partial remission with salvage chemotherapy were randomly assigned using a factorial design to rituximab purging (P+; 375 mg/m(2) once per week for 4 weeks) or observation (NP) before HDC-ASCT and to maintenance rituximab (M+; 375 mg/m(2) once every 2 months for four infusions) or observation (NM).

RESULTS

From October 1999 to April 2006, 280 patients were enrolled. The median age was 51 years (range, 26 to 70 years), and baseline characteristics were well balanced between groups. On average, patients were 44 months (range, 3 to 464 months) from diagnosis, with 79% having received two lines and 15% three lines of prior therapy. Median follow-up was 8.3 years. In contrast to purging, 10-year progression-free survival (PFS) was 48% for P+ and 42% for NP groups (hazard ratio [HR], 0.80; 95% CI, 0.58 to 1.11; P = .18); maintenance had a significant effect on PFS (10-year PFS, 54% for M+ and 37% for NM; HR, 0.66; 95% CI, 0.47 to 0.91; P = .012). Overall survival (OS) was not improved by either rituximab purging or maintenance.

CONCLUSION

Rituximab maintenance after HDC-ASCT is safe and significantly prolongs PFS but not OS in patients undergoing transplantation for relapsed FL. Pretransplantation rituximab in vivo purging, even in rituximab-naive patients, failed to improve PFS or OS.

Changing role of stem cell transplantation in follicular lymphoma

Patients with advanced follicular lymphoma (FL) have numerous treatment options, including observation, radiotherapy, single-agent or combination chemotherapy, mAbs, and radioimmunoconjugates. These therapies can extend progression-free survival but none can provide a cure. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curable therapy for FL, with the field shifting more toward the use of reduced-intensity conditioning regimens because of the lower associated nonrelapse mortality compared with myeloablative regimens. However, GVHD and infection are still problematic in the allo-HSCT population. Autologous HSCT (auto-HSCT) confers high response rates and prolongs progression-free survival in relapsed patients who are chemosensitive, and an increasing amount of data suggest that auto-HSCT may be curative if offered to relapsed patients who are not heavily pretreated. Auto-HSCT has no role as consolidation therapy for patients in first remission based on the results from 3 large randomized trials. Novel conditioning regimens with radioimmunoconjugates have been used in both auto-HSCT and allo-HSCT regimens and results have shown efficacy even in chemorefractory patients. Therefore, with the exception of patients in first remission, the optimal timing for HSCT remains controversial. However, the outcomes seen after auto-HSCT and allo-HSCT continue to improve, and HSCT represents a treatment modality that should be considered in all FL patients, especially while their disease remains chemoresponsive.

Myeloablative chemotherapy for chemo-sensitive recurrent follicular lymphoma: potential benefit in second relapse

Defining the role of high-dose therapy with autologous stem cell rescue in the therapeutic algorithm of follicular lymphoma remains a major challenge. In contrast to the acknowledged poor outcome associated with cyclophosphamide/total body irradiation conditioning in heavily pretreated patients, the prognostic impact of the number of previous therapy lines in patients treated with the chemotherapy-only containing regimen, BEAM, is unknown. From 1997 to 2008 80 patients (41 males, 39 females; median age, 51 years; range, 31-67) received high-dose therapy with autologous stem cell rescue with BEAM for relapsed follicular lymphoma at our center. Overall survival and time-to-progression were analyzed according to the number of prior treatment lines. The median number of previous treatment lines was three, with 61% of the patients having received more than three lines (including rituximab in 47%). After a median follow-up of 76 months (range, 14-160), three patients developed secondary myelodysplastic syndrome. The 5-year overall survival rate was 71% and 5-year time-to-progression was 44%. There were no differences in time-to-progression or overall survival according to the number of previous treatment lines or episodes of disease. In conclusion, high-dose therapy with autologous stem cell rescue with BEAM appears to be equally effective in second or third remission of follicular lymphoma.

Who should be really considered as a poor mobilizer in the plerixafor era?

Patients with a number of peripheral CD34+ cells ≥20/μL have recently been defined in the literature as "poor mobilizers". We retrospectively reviewed medical records from a total of 248 patients affected by hematological malignancies or solid tumors undergoing peripheral blood stem cell collection following chemotherapy plus G-CSF. On the basis of the CD34+ cell peak in peripheral blood following mobilization therapy, patients were defined as good mobilizers (group A, CD34+ cells ≥20/μL), relative poor mobilizers (group B, CD34+ cells <20 and ≥8/μL) and absolute poor mobilizers (group C, CD34+ cells <8/μL). One hundred and seventy-seven (71%) patients resulted good mobilizers, 35 (14%) patients relative poor mobilizers and 36 (15%) patients absolute poor mobilizers. Target of stem cell collection was ≥2.0×10(6) CD34+cells/kg for each transplantation procedure. All patients in group A, 20 patients in group B (57%) and 1 patient in group C (2.7%) were able to collect ≥2.0×10(6) CD34+cells/kg. The multivariate analysis confirmed that more than three lines of previous chemotherapy and a previous autologous PBSC transplantation negatively affect mobilization of CD34+ cells in peripheral blood. Our data suggest that a number of CD34+ cells ≥20/μL does not always result in a failed stem cell collection and in fact in our patient series more than 70% of the patients defined as poor mobilizers have indeed collected the minimum number of 2.0×10(6) CD34+cells/kg required for a successful transplantation. The use of new agent such as CXCR4 antagonist plerixafor might further improve mobilization efficacy in such patients.

Patterns and outcome of relapse after autologous stem cell transplantation for mantle cell lymphoma

BACKGROUND

Autologous stem cell transplantation (autoSCT) has improved the outcome of patients with mantle cell lymphoma (MCL) considerably. However, little is known about the patterns and outcome of MCL recurrence after autoSCT.

METHODS

The authors conducted a retrospective study of 118 patients with MCL who underwent autoSCT from August 1992 to August 2008 at 3 different referral centers in Germany.

RESULTS

Fifty-two relapses occurred for a cumulative incidence of 46% after 5 years. Only 3 patients relapsed after 5 years (at 90 months, 91 months, and 171 months) after undergoing autoSCT. A Cox regression analysis of the incidence of relapse identified not receiving rituximab before autoSCT and undergoing salvage autoSCT as predictive factors for relapse, whereas cytosine arabinoside intensification; a total body irradiation-based, high-dose regimen; patient age; and year of transplantation had no influence. The median overall survival (OS) after relapse was 23 months. Twenty patients (39%) underwent allogeneic stem cell transplantation (alloSCT) for relapse, and 11 of those patients remained in ongoing complete remission at the time of the current report. It is noteworthy that there were 4 long-term survivors who lived for >5 years after relapse even without undergoing alloSCT. A Cox regression analysis of OS after relapse revealed that the response duration after autoSCT was an adverse predictor of OS, whereas alloSCT was associated with a significantly longer OS after relapse.

CONCLUSIONS

The current results indicated that autoSCT was capable of inducing long-term remission up to 16 years after treatment, but the outcome of patients with MCL who relapsed after autoSCT was poor, especially if their response duration after autoSCT was short. However, for a subset of patients with relapsed MCL, alloSCT may offer the possibility of durable survival, and individual patients can enjoy long-term survival after relapse even without undergoing alloSCT.

Extended follow-up of autologous bone marrow transplantation with 4-hydroperoxycyclophosphamide (4-HC) purging for indolent or transformed non-Hodgkin lymphomas

Autologous blood or marrow transplantation (ABMT) for low-grade lymphomas can prolong event-free survival (EFS) but requires long-term follow-up. We report one of the longest follow-ups to a prospective transplantation study in such diseases. On a phase II study, 80 patients with low-grade, transformed, or mantle cell lymphoma received ABMT with 4-hydroperoxycyclophosphamide (4-HC) purging as part of initial or salvage therapy. Diagnoses included nontransformed follicular lymphoma in 63% and transformed lymphoma in 15%. With 16.6-year median follow-up for survival, actuarial 10-year EFS and overall survival (OS) were 34% (95% confidence interval [CI], 25%-46%) and 45% (35%-57%). Median EFS and OS were 3.0 and 8.0 years. Early nonrelapse mortality incidence was 8%; myelodysplastic syndrome or leukemia incidence was 4%. Most relapses occurred within 3 years, with a median time to diagnosis of relapse of 1.8 years (range: 0.1-15.6 years). On multivariate analysis, age >50 years, ≥3 prior chemotherapy regimens, and ABMT after relapse were associated with significantly inferior survival. Fifteen patients (19%) were event-free >15 years after transplantation, raising the possibility of a plateau in the progression-free survival curve. Thus, 4-HC-purged ABMT can produce extended remissions in a subgroup of patients with indolent lymphomas.

Rimonabant-induced apoptosis in leukemia cell lines: activation of caspase-dependent and -independent pathways

Rimonabant (SR141716), a cannabinoid CB1 receptor antagonist known for anti-obesity activity, has more recently been shown to inhibit tumor cell growth. Here we demonstrated the antitumor potential of SR141716 in leukemia-derived cell lines and its low toxicity in normal cells (PBMC). SR141716 (1-20microM range of doses) reduced Jurkat and U937 cell number by activating death signals as well as affecting cell cycle progression. The most prominent response in U937 to SR141716 was a G(0)/G(1) block, while in Jurkat cells there was activation of cell death processes. SR141716-treated cells exhibited the morphological and biochemical features of apoptosis and to some extent necrosis. Apoptotic mode of cell death was confirmed in both cell lines by analysis of cell morphology, phosphatidylserine exposure and DNA fragmentation. Moreover, the drug was found to induce an early and robust mitochondrial membrane depolarization. In Jurkat cells the apoptotic process was typically caspase-dependent, while in U937 caspase-independent pathways were also activated. The contribution of PARP activation to SR141716-induced apoptosis in U937 was suggested by protein PARylation, AIF release and apoptosis reversal by PARP inhibitors. Moreover, SR141716 negatively modulated, especially in U937, the PI3K/AKT pathways. In conclusion, our data indicate that SR141716 elicits alternative response and/or cell death pathways depending on the cell type affected.

Lymphoma in adolescents and young adults

Non-Hodgkin (NHL) and Hodgkin (HL) lymphomas are represented prominently in the adolescent and young adult (AYA) population. These diseases represent 11% of total cancer diagnoses in children, 4% in those 40 years of age and older, and 13% in AYA (aged 15-39 years). Although age-adjusted incidence rates of NHL increase with age, the more aggressive lymphomas are seen more commonly in the younger population with a transition to low-grade, indolent subtypes as the population ages. Burkitt lymphoma, diffuse large B-cell lymphoma, lymphoblastic lymphoma, and anaplastic large cell lymphoma make up the most common subtypes in the AYA population, although within the subgroup age 30-39 years, follicular lymphoma becomes more prominent. As a result, much of the armamentarium in the treatment of aggressive NHL and HL in adults is based on data from pediatric clinical trials. There are obvious limitations to this approach. It is vital that we gain a more thorough understanding of the biology and therapeutic responsiveness of NHL and HL in the AYA population. Thus, we must leverage the large prospective and retrospective trials that have been completed to date and redirect our approaches to cancer care in this unique population. We review the epidemiological data on NHL and HL from the Surveillance, Epidemiology and End Results registries as a cornerstone for a comparative analysis of therapeutic outcomes available in this population.

Allogeneic stem cell transplantation in follicular lymphoma: recent progress and controversy

Allogeneic stem cell transplantation (allo HCT) is a curative treatment for follicular lymphoma, but is hampered by a relatively high treatment-related mortality and by difficulties in identifying high-risk groups for whom transplant is warranted. Results with myeloablative conditioning have improved, but the field has shifted largely to reduced-intensity conditioning and non-myeloablative transplantation, though morbidity and mortality are also substantial. Some groups have investigated T cell–depleted transplantation, which results in a low rate of chronic graft-versus-host disease (GVHD) and, in most studies, excellent rates of disease control. Overall, outcome after alloHCT for follicular lymphoma correlates more with disease status, with performance status and with comorbidities than with any particular conditioning regimen used. For patients with chemotherapy-sensitive disease, the treatment-related mortality has stabilized in the 15% to 20% range and, depending on the method of GVHD prophylaxis and the donor type, there is an additional 20% to 60% incidence of chronic GVHD. For patients with chemotherapy-refractory disease, both treatment-related mortality and recurrence rates are much higher, but their prognosis is dismal with other treatments and some may be cured, particularly with myeloablative transplants. Ongoing studies focus on improving conditioning regimens, on prevention of disease recurrence and on decreasing chronic GVHD.