Rituximab maintenance after autologous stem cell transplantation prolongs response duration in non-naive rituximab follicular lymphoma patients: a single institution experience.

We retrospectively evaluated the role of rituximab (R) in maintenance treatment after autologous stem cell transplantation performed in patients with relapsed follicular lymphoma. We compared the outcome of 67 follicular lymphoma (FL) patients according to the use of rituximab maintenance (RM) or not. All patients received rituximab plus chemotherapy before autologous stem-cell transplantation (ASCT). Patients received median of two lines of prior therapy. The RM schedule was one injection of rituximab every 3 months for 2 years. Median follow-up is 4.6 years. The 3-year progression-free survival (PFS) after ASCT was 86 % with RM vs. 46 % without (p = 0.0045). Median is not reached in the RM arm vs. 31 months in non-RM arm. The 3-year OS was 96 % with RM vs. 78 % without (p = 0.059). The present monocentric study shows that 2 years of RM after ASCT significantly increases response duration for non-naive rituximab relapsed FL patients compared with observation.

Upfront allogeneic stem-cell transplantation for patients with nonlocalized untreated peripheral T-cell lymphoma: an intention-to-treat analysis from a single center.

BACKGROUND: Peripheral T-cell lymphomas (PTCLs) are rare and heterogeneous diseases with dismal outcome when treated with chemotherapy alone. Because allogeneic stem-cell transplantation (allo-SCT) can cure relapse/refractory patients, we hypothesized that upfront allo-SCT may provide a better outcome. Therefore, all patients that presented with advanced PTCL in our institution at diagnosis were scheduled to undergo upfront allo-SCT after induction chemotherapy. PATIENTS AND METHODS: The aim of the present work was to assess the feasibility and toxicity of upfront allo-SCT. From 2004 to 2012, 49 newly diagnosed PTCL patients were scheduled to receive upfront allo-SCT. A human leukocyte antigen-matched donor was found for 42 patients: related to the patient in 15 cases, unrelated in 20 cases, and suitable cord blood units were used in 7 cases. RESULTS: After induction chemotherapy, 17 patients reached complete remission and 29 (60%) proceeded to upfront allo-SCT. For all patients, the 1 and 2-year overall survival (OS) rates were 59% [95% confidence interval (CI) 47-75] and 55% (95% CI 43-71), respectively. The most frequent reason we did not proceed to allo-SCT was disease progression or insufficient response after induction. For transplanted patients, the 1- and 2-year OS were 76% (95% CI 62-93) and 72.5% (95% CI 58-91), respectively. Toxicity-related mortality (TRM) 1 year after allo-SCT was only 8.2% (95% CI 0-18.5). The 2-year progression-free survival (PFS) rate of patients who did not proceed to allo-SCT (n = 20) was below 30%. The disease status at the time of transplantation was a strong predictive marker for both PFS and OS in transplant patients. CONCLUSIONS: Upfront allo-SCT in PTCLs is feasible with low TRM, and it provides long-term disease control. However, one-third of patients remain chemo-refractory and, thus, new therapeutic approaches are warranted. The role of upfront allo-SCT compared with other therapeutic approaches in PTCLs requires investigation in randomized studies.

Differential expression of Bcl-2 in human plasma cell disorders according to proliferation status and malignancy.

Multiple myeloma (MM) is a malignancy characterized by a very slow proliferation of malignant plasma cells leading to their accumulation within the bone marrow. This suggests that resistance to apoptosis may play a critical role both in the pathogenesis and resistance to treatment of MM. Bcl-2 is a key protein for the regulation of apoptosis. However, it has been shown that this protein also regulates the state of proliferation. In the current study, we show that malignant plasma cells from both the bone marrow and peripheral blood express high levels of Bcl-2 and are slowly proliferating cells. In contrast, myeloma cells from extramedullary sites (ie pleural effusion, ascitis, mammary and gastric plasmacytoma) express Bcl-2 weakly while being highly proliferative. Normal non-dividing bone marrow plasma cells express high levels of Bcl-2 protein. In contrast, four highly proliferative reactive plasmacytosis express weak levels of Bcl-2. We conclude that there is an inverse correlation between Bcl-2 expression and the proliferation rate of both normal and malignant plasma cells. These data may be explained by the double function of Bcl-2, ie its well known function as an anti-apoptotic molecule and its intriguing function as an inhibitory molecule of cell proliferation.

Immunoglobulins D and M multiple myeloma variants are heavily mutated.

Multiple myeloma (MM) is a B-cell malignancy characterized by the expansion of malignant plasma cells within the bone marrow. Previous studies that have examined the Ig VH genes of IgG and IgA MMs have shown the presence of somatic mutations, suggesting that in these cases, the myeloma precursor cell passed through the phase of antigenic selection within the germinal center but is no longer exposed to the somatic mutation process. However, no information about this matter is available in the rare IgD and IgM MM variants. Therefore, we have analyzed the Ig VH genes of three IgD, one IgM, and one biclonal (IgG and IgM) MM for the presence of somatic mutations. Our study demonstrates that all of these myeloma clones have accumulated a high number of somatic mutations within their Ig VH genes but show no intraclonal variation. Moreover, proof that the clone sustained a strong antigenic selection pressure could be provided in three cases (one IgD and two IgMs). Therefore, this study strongly implies that IgD and IgM MMs emerge from a postgerminal center preswitched B cell that is no longer exposed to the somatic mutation process or able to undergo further isotype switching in vivo.

Melphalan 220 mg/m2 followed by peripheral blood stem cell transplantation in 27 patients with advanced multiple myeloma.

Twenty-seven patients with advanced multiple myeloma received high-dose therapy with 220 mg/m2 i.v. melphalan (HDM220) followed by autologous stem cell transplantation. At the time of HDM220, nine patients had primary refractory disease and 18 were in relapse after having responded to prior high-dose therapy. No toxic deaths were observed. The major adverse side-effect was grade 4 mucositis in 63% of patients. Two patients experienced reversible paroxysmal atrial fibrillation after HDM220. For the whole group of patients, the actuarial 3-year overall survival (OS) and event-free survival (EFS) are 36.1 and 16.9%, respectively. The probability of OS and EFS was significantly lower in patients treated for refractory relapse (22.9 and 0% at 2 years, respectively) as compared to primary refractory patients (66.7 and 64.3% at 2 years, respectively) or patients treated for chemosensitive relapse (42.9% at 2 years) (P = 0.0001). Low beta2-microglobulin and CRP levels at the time of HDM220 were associated with a better OS and EFS. Our data suggest that HDM220 followed by ASCT should be considered in patients with primary refractory disease or chemosensitive disease relapsing after prior intensive therapy.

Peripheral blood stem cell transplantation as front-line therapy in patients aged 61 to 65 years: a pilot study.

The aim of the present trial was to investigate the feasibility of high-dose therapy followed by autologous peripheral blood stem cell transplantation (PBSCT) as a component of front-line treatment in patients with disseminated intermediate- and high-grade non-Hodgkin's lymphoma (NHL) aged 61-65 years. From October 1993 to June 1996, 14 consecutive patients entered this single-center prospective pilot trial. Patients were five males and nine females, median age 63 (range 61-65). The first-line treatment consisted of three courses of CHOP therapy. Patients achieving either a partial response (PR) or a complete response (CR) after initial therapy were eligible for PBSCT, while those with refractory or progressive disease were not autografted but included in the feasibility study in an intent-to-treat analysis. Of the 14 patients, 11 achieved either a CR (one) or a PR (10) after three courses of CHOP while the three patients with no response were not autografted and subsequently died of progressive disease. PBSC collection was feasible in responding patients after G-CSF priming (10 microg/kg/day for 6 days). Conditioning therapy was the BEAM protocol. All patients engrafted after PBSCT. The median time to granulocyte (>0.5 x 10(9)/l) and platelet recovery (>25 x 10(9)/l) was 12 (range 9-18) and 13 days (range 7-22), respectively. No toxic deaths VOD or IP were observed. Four of the 11 responding patients relapsed 2, 7, 9 and 12 months after PBSCT, respectively, and all died from progressive disease. Overall, 7/14 patients are alive and free from disease, 16-43 months after initial diagnosis (median 28). The actuarial overall survival is 45.7 %, and the actuarial event-free survival is 50% at 3.5 years. This study shows the feasibility of high-dose therapy and PBSCT in patients with intermediate- or high-grade disseminated NHL aged 61-65 years. Such patients should not be excluded from trials evaluating the role of ASCT as part of initial treatment for disseminated and histologically aggressive NHL.

The retinoblastoma susceptibility gene RB-1 in multiple myeloma.

Genetic mechanisms leading to the development of multiple myeloma (MM) remain poorly understood. Given the frequency of chromosome 13 deletion in MM and the localization in 13q14 of the retinoblastoma susceptibility gene RB-1, an involvement of RB-1 in MM pathogenesis has been proposed. Moreover, interleukin-6 (IL-6) has been shown to be the main growth factor for MM in vitro and in vivo. The product of the RB-1 gene (pRB) can down-regulate IL-6 gene expression. Absence of pRB may then induce an autocrine IL-6 expression in myeloma cells and contribute to the autonomous growth of MM. As assessed in this review, heterozygous deletion of RB-1 is very common in MM but does not alter gene transcription and protein expression. Nevertheless, homozygous deletion of RB-1 has been identified in some MM patients with advanced disease and in the IL-6-autocrine human myeloma cell line U266. Thus, even if inactivation of RB-1 appears to be only a rare and late oncogenic event in MM and is not likely to represent the main mechanism involved in IL-6 up-regulation in MM, definitive assessment of the actual role played by RB-1 in MM pathogenesis still needs further investigation particularly the examination of pRB function.

Detection of minimal residual disease in multiple myeloma and acute leukaemia.

The importance of minimal residual disease detection has increased due to the advanced therapeutic protocols available for multiple myeloma and acute leukaemia. High-dose chemotherapy, followed by stem cell transplantation is often used in patients with multiple myeloma. But despite a longer disease-free period and overall survival, all patients relapse. In the treatment of acute leukaemia, there are similar problems. The present strategy is to give continuous chemotherapy to eradicate minimal residual disease. In this review, we consider the methods used to detect and quantify minimal residual disease. At present, the most effective seem to be those based on the use of polymerase chain reactions to detect the malignant cells.

Impact of high-dose chemotherapy followed by auto-SCT for positive interim [18F] FDG-PET diffuse large B-cell lymphoma patients.

[(18)F] fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is increasingly used for response assessment in diffuse large B-cell lymphoma (DLBCL). A positive interim FDG-PET was shown to be associated with an unfavorable outcome in high-grade non-Hodgkin's lymphomas. For positive interim FDG-PET patients, the question of increasing the intensity of treatment using high-dose chemotherapy followed by auto-SCT (HDC-ASCT) remains unanswered. We retrospectively analyzed the prognostic value of FDG-PET in 42 DLBCL patients who were systematically evaluated at time of diagnosis, before and after HDC-ASCT. Of note, HDC-ASCT was part of the initial treatment strategy, while FDG-PET results did not influence the treatment approach. Results and outcome were analyzed according to FDG-PET results before and after HDC-ASCT. Patients were classified into three groups according to FDG-PET results before and after HDC-ASCT: those who were negative before and after (-/-; n=25), positive before and negative after (+/-; n=9) or positive before and after (+/+; n=8). The median follow-up was 34.5 (range, 19-74) months. The median EFS was significantly lower for the +/+ group (27.4 months) as compared with other groups (median not reached; P=0.0001). More importantly, there was no difference in term of EFS between the -/- group compared with the +/- group. These results suggest that HDC-ASCT can significantly improve the bad prognosis, otherwise indicated by a positive interim FDG-PET.

[Role of glucocorticoids in the treatment of multiple myeloma]. / Place des glucocorticoïdes dans le traitement du myélome multiple.

Glucocorticoids are frequently used for the treatment of multiple myeloma (MM), more often in association with other cytotoxic drugs than in monotherapy. The aim of our analysis was to appreciate the true interest of these agents and to evaluate their best indications and prescription modalities. For this purpose, we have analysed clinical trials evaluating the anti-tumoral effects of glucocorticoids in MM. It appears that there are no published data demonstrating the usefulness of low-dose corticoids like prednisone or prednisolone in the treatment of MM. However, high-dose steroids like dexamethasone or methylprednisolone had proven their clearcut anti-tumoral action. Nevertheless, controlled studies are necessary to show the real benefit of such treatment on MM patient survival. This study underlines the two potential indications of high-dose glucocorticoids for MM treatment: (i) for previously unresponsive disease (patients who clearly progress with initial therapy), (ii) for previously untreated patients more than 65 years old.

The gp 130 family cytokines IL-6, LIF and OSM but not IL-11 can reverse the anti-proliferative effect of dexamethasone on human myeloma cells.

In order to understand the mechanisms supporting steroid escape in patients with multiple myeloma (MM), three IL-6 autocrine human myeloma cell lines, LP1, OPM2 and L363, have been treated with dexamethasone in the presence or absence of cytokines belonging to the gp 130 family: IL-6, LIF, OSM and IL-11. With pharmacological doses of dexamethasone, a dramatic growth arrest was observed in all the cell lines. IL-6 completely reversed this inhibition. Of note, this IL-6 induced reversion was still seen with very low amounts of IL-6 (12 pg/ml). Finally, whereas LIF and OSM had clear growth-promoting effects on OPM2 only, both cytokines (but not IL-11) reversed the dexamethasone-induced growth arrest in all the cell lines. Therefore the high levels of IL-6 (ng/ml) observed in the MM intermediate milieu and the putative presence of LIF and OSM can easily counteract the effects of dexamethasone in vivo.

Anti-cancer therapy using dendritic cells and apoptotic tumour cells: pre-clinical data in human mesothelioma and acute myeloid leukaemia.

We have recently reported in an experimental model, that treatments based on the injections of dendritic cells which had phagocytosed apoptotic bodies derived from tumour cells were particularly effective in the cure of tumour-bearing animals. We proposed that systems using processing and presentation of antigenic molecules from antigen-presenting cells primed with apoptotic bodies can offer new opportunities in anti-cancer treatment. We first established the technical conditions for purification, characterisation and production of tumour cells isolated from fresh pleural liquid or blood. Then we compared efficacy of different apoptotic inducers agents on the cancer cells in culture. The apoptotic tumour cells were purified, characterised and maintained in coculture with monocytes-derived immature dendritic cells. We subsequently investigated the effect of the maturation process on phagocytosis of apoptotic bodies. We have shown that whatever the nature of the apoptotic cells they are phagocytosed by the dendritic cells which were efficiently matured using the combination of TNFalpha+Poly I:C. Furthermore, we demonstrated that the generation of the mature dendritic cells pulsed with apoptotic tumour cells, successfully generated CD4(+) (Th1) and CD8(+) (CTL) cells. All the experimental procedures that we have used were developed with clinical use in mind, using Good Manufacturing Products. We are presently investigating the feasibility of such a "vaccine" for the treatment of asbestos mesothelioma or acute myeloid leukaemia.

High incidence of deletions but infrequent inactivation of the retinoblastoma gene in human myeloma cells.

We have studied the retinoblastoma (RB-1) susceptibility gene status and pRB expression in 22 human myeloma cell lines (HMCL) and in 10 patients with advanced multiple myeloma (MM). Deletions of the RB-1 gene were observed in 81% (17/21) of the informative HMCL, regardless of their paracrine or autocrine interleukin-6 (IL-6) status. Among the deleted HMCL, only one (U266) had a biallelic deletion and lacked pRB expression. Monoallelic deletions had no consequence on the RB-1 gene activation and pRB expression. One patient of 10 presented the same biallclic deletion as U266 and six of 10 had monoallelic deletions. We conclude that monoallelic deletions of the RB-1 gene are frequent in HMCL and MM patients but have no consequence on gene activation and pRB expression.

V(H) gene analysis of IgM-secreting myeloma indicates an origin from a memory cell undergoing isotype switch events.

IgM-secreting plasma cell tumors are rare variants of typical isotype-switched multiple myeloma with a similar disease outcome. To probe the origin and clonal history of these tumors, we have analyzed V(H) gene sequences in 6 cases. Potentially functional tumor-derived V(H) genes were all derived from V(H)3, with the V(3-7) gene segment being used by 4 of 6. All were somatically mutated, with a mean deviation from germline sequence of 5.2% (range, 3.1% to 7.1%). The distribution of replacement mutations was consistent with antigen selection in 4 of 6 cases, and no intraclonal heterogeneity was observed. Clonally related switched isotype transcripts were sought in 4 cases, and Cgamma transcripts with tumor-derived CDR3 sequence were identified in 2 of 4. These findings indicate that IgM-secreting myelomas are arrested at a postfollicular stage at which somatic mutation has been silenced. Isotype switch variants show the cell of origin to be at the IgM to IgG switch point. These features indicate that the final neoplastic event has occurred at a stage immediately before that of typical isotype-switched myeloma. One possibility is that IgM myeloma involves the previously identified precursor cell of typical myeloma.

Persistence of residual tumour cells after cytokine-mediated ex vivo expansion of mobilized CD34+ blood cells in multiple myeloma.

Mobilized CD34+ blood cells were immunomagnetically enriched from leukapheresis products in five multiple myeloma (MM) patients. Thawed samples of selected CD34+ cells were cultured for up to 21 d in a liquid and stroma-free culture system with different combinations of recombinant cytokines. The most successful cell expansion was obtained when a combination of rh-IL-1beta, rh-IL-3, rh-IL-6, rh-SCF, rh-G-CSF and rh-GM-CSF was used. After 14 d this mixture gave a 120-187-fold overall increase of total nuclear cells and a 4-8-fold overall increase of early CFU-GM numbers. In four patients a very sensitive patient-specific PCR analysis showed the presence of monoclonal cells in the initial leukapheresis products. After immunomagnetic separation a tumour cell depletion of 2-4 logs was observed, although all samples still contained malignant cells. Cell suspensions that were cultured with the most potent cytokine combination showed tumour contamination in two-thirds of evaluable cases at the moment of maximal CFU-GM output. Serial cDNA dilution experiments indicated that the positive PCR results at day 14 reflected the persistence of pre-culture tumour cells rather than in vitro expansion of tumour cells in two cases. This study demonstrates that ex vivo expansion of myeloid precursor cells from mobilized CD34+ cells in MM patients does not always result in an effective purging of residual tumour cells. On the other hand, our culture conditions do not seem to favour in vitro expansion of malignant cells, despite the use of a cytokine cocktail that includes potential myeloma growth factors.

Expression of CD28 and CD40 in human myeloma cells: a comparative study with normal plasma cells.

CD28 and CD40 are important activation pathways for T and B lymphocytes, respectively. The aim of this study was to determine the phenotype of plasma cells (PCs) and the expression of these two molecules, CD28 and CD40. Therefore, we have compared their expression on normal PCs from bone marrows and tonsils with that of freshly explanted malignant PCs from 31 patients with multiple myeloma (MM) and those from 12 human myeloma cell lines. For this purpose, we first described a new approach to identify plasma cells in bone marrow using two-color immunofluorescence analysis with anti-CD38 and B-B4 antibodies. B-B4 specifically recognizes all PC; all B-B4 cells are located within the CD38 bright fraction and vice versa. CD19 and CD56 expression, which was previously shown to discriminate normal from malignant PCs, was also evaluated. In the current report, we show that normal PCs express CD19, CD40, and CD56 (weakly as a subset) and lack CD28. Regardless of whether they express CD19, CD56 is clearly upregulated during the medullary chronic and accelerated phases of MM, but is absent in patients with extramedullary involvement. Although the level of CD40 expression is variable, only patients in accelerated phases expressed high CD40 levels. Finally, whereas CD28 was negative in chronic phase (as in normal PCs), it was expressed in 63% of the patients in accelerated phases and 100% of cell lines. Our data strongly suggest that both disease activity and medullary homing (or not) are correlated with the expression of CD19, CD40, CD28, and CD56 on human myeloma cells.