Maintenance thalidomide following single cycle autologous peripheral blood stem cell transplant in patients with multiple myeloma

Role of Stem Cell Transplantation in Multiple Myeloma

Autologous stem cell transplantation (auto-SCT) has been the standard of care in eligible newly diagnosed multiple myeloma (MM) patients. Outcomes of patients with MM have improved significantly due to the advent of several novel drugs. Upfront use of these drugs in induction therapy has significantly increased the rate and depth of responses that have translated into longer remission and survival. This has now raised a debate regarding the role and relevance of auto-SCT in the management of myeloma. However, clinical trials have confirmed the utility of auto-SCT even in the era of novel drugs. Tandem auto-SCT followed by maintenance has shown a progression-free survival (PFS) benefit in high-risk MM, and hence can be considered in young and fit patients with high-risk disease. Auto-SCT has the advantages of resetting the bone marrow microenvironment, short-lived toxicity compared to the long-term physical and financial toxicities of continued chemotherapy in the absence of SCT, very low transplant-related mortality (TRM) in high volume centers, and providing longer disease-free survival when followed by maintenance therapy. Allogeneic SCT is one potentially curative option for MM, albeit with an increased risk of death due to high TRM. Strategies to modulate the graft-versus-host disease (GVHD) while maintaining or improving the graft-versus-myeloma (GVM) effect could place allogeneic SCT back in the treatment armamentarium of MM.

Lenalidomide vs bortezomib maintenance choice post-autologous hematopoietic cell transplantation for multiple myeloma

Maintenance therapy post-autologous hematopoietic cell transplantation (AHCT) with either lenalidomide or bortezomib for multiple myeloma (MM) have separately been shown to improve progression-free survival (PFS), but have never been directly compared. We performed a retrospective study to investigate progression-free and overall survival outcomes and toxicities of lenalidomide maintenance therapy compared with bortezomib maintenance in MM patients post-AHCT. This study included 156 patients who received post-AHCT lenalidomide or bortezomib maintenance therapy for MM. The primary outcome was PFS. Ninety-two patients received lenalidomide maintenance and 64 received bortezomib maintenance post-AHCT. By multivariable analysis, maintenance therapy choice and cytogenetics risk did not impact PFS or OS. Staging by International Staging System and pre-maintenance disease response were the greatest predictors for PFS. Treatment-related toxicities were as anticipated with 5.4% of patients receiving maintenance lenalidomide experiencing secondary primary malignancies (SPMs) compared with 3% for bortezomib. These findings suggest there were no differences in PFS or OS between lenalidomide and bortezomib maintenance therapy options for post-transplantation MM patients. These data should be validated in a larger, prospective cohort to determine if maintenance choice should be guided by side effect profile and patient anticipated tolerance rather than by disease biology alone.

Total marrow irradiation as part of autologous stem cell transplantation for Asian patients with multiple myeloma

To compare the outcomes of melphalan 200 mg/m² (HDM200) and 8 Gy total marrow irradiation (TMI) delivered by helical tomotherapy plus melphalan 140 mg/m² (HDM140 + TMI 8 Gy) in newly diagnosed symptomatic multiple myeloma (MM) Asian patients. Between 2007 and 2010, nine consecutive myeloma patients who were scheduled to undergo autologous stem cell transplantation (ASCT) were studied. The patients received three cycles of vincristine-adriamycin-dexamethasone (VAD) regimen as induction chemotherapy, and if they had a partial response, peripheral blood stem cells were collected by dexamethasone-etoposide-cyclophosphamide-cisplatin (DECP). In arm A, six patients received the HDM200. In arm B, three patients received HDM140 + TMI 8 Gy. In arm B, the neutropenic duration was slightly longer than in arm A (P = 0.048). However, hematologic recovery (except for neutrophils), transfusion requirement, median duration of hospitalization, and the dose of G-CSF were similar in both arms. The median duration of overall survival and event-free survival was similar in the two arms (P = 0.387). As a conditioning regiment, HDM140 + TMI 8 Gy provide another chance for MM Asian patients who were not feasible for HDM200.

Long-term follow-up of MRC Myeloma IX trial: Survival outcomes with bisphosphonate and thalidomide treatment

PURPOSE

Medical Research Council (MRC) Myeloma IX was a phase III trial evaluating bisphosphonate and thalidomide-based therapy for newly diagnosed multiple myeloma. Results were reported previously after a median follow-up of 3.7 years (current controlled trials number: ISRCTN68454111). Survival outcomes were reanalyzed after an extended follow-up (median, 5.9 years).

EXPERIMENTAL DESIGN

At first randomization, patients (N = 1,970) were assigned to bisphosphonate (clodronic acid or zoledronic acid) and induction therapies [cyclophosphamide-vincristine-doxorubicin-dexamethasone (CVAD) or cyclophosphamide-thalidomide-dexamethasone (CTD) followed by high-dose therapy plus autologous stem cell transplantation for younger/fitter patients (intensive pathway), and melphalan-prednisone (MP) or attenuated CTD (CTDa) for older/less fit patients (nonintensive pathway)]. At second randomization, patients were assigned to thalidomide maintenance therapy or no maintenance. Interphase FISH (iFISH) was used to analyze cytogenics.

RESULTS

Zoledronic acid significantly improved progression-free survival (PFS; HR, 0.89; P = 0.02) and overall survival (OS; HR, 0.86; P = 0.01) compared with clodronic acid. In the intensive pathway, CTD showed noninferior PFS and OS compared with CVAD, with a trend toward improved OS in patients with favorable cytogenics (P = 0.068). In the nonintensive pathway, CTDa significantly improved PFS (HR, 0.81; P = 0.007) compared with MP and there was an emergent survival benefit after 18 to 24 months. Thalidomide maintenance improved PFS (HR, 1.44; P < 0.0001) but not OS (HR, 0.96; P = 0.70), and was associated with shorter OS in patients with adverse cytogenics (P = 0.01).

CONCLUSIONS

Long-term follow-up is essential to identify clinically meaningful treatment effects in myeloma subgroups based on cytogenetics.

Risk of secondary primary malignancies in maintenance therapy for multiple myeloma

SUMMARY There have been many advances in the treatment of patients with multiple myeloma over the past decade. As a result, the average life expectancy of patients with MM has improved. New medications, including immunomodulatory drugs (thalidomide, lenalidomide and pomalidomide) and proteasome inhibitors (bortezomib and carfilzomib) have entered clinical practice. On average, these medications are easier to tolerate than traditional chemotherapy allowing for long-term use of these drugs in a maintenance fashion. Clinical trials have appeared to establish the benefit of lower dose maintenance therapy for MM patients after induction chemotherapy and/or autologous stem cell transplant. These medications have been shown to improve not only the progression-free survival of patients, but also improve their overall survival compared with observation alone in some pivotal studies. With long-term maintenance therapy, a notable increase in secondary primary malignancies has been described. The exact mechanism behind this increase is uncertain, but may relate to the persistence of CD34+ cells in the setting of continued immunomodulatory exposure. Despite the concern of secondary primary malignancies, the risk:benefit ratio still favors maintenance therapy in many patients with multiple myeloma.

The role of maintenance thalidomide therapy in multiple myeloma: MRC Myeloma IX results and meta-analysis

Thalidomide maintenance has the potential to modulate residual multiple myeloma (MM) after an initial response. This trial compared the effect of thalidomide maintenance and no maintenance on progression-free survival (PFS) and overall survival (OS) in MM patients. After intensive or nonintensive induction therapy, 820 newly diagnosed MM patients were randomized to open-label thalidomide maintenance until progression, or no maintenance. Interphase FISH (iFISH) analysis was performed at study entry. Median PFS was significantly longer with thalidomide maintenance (log-rank P < .001). Median OS was similar between regimens (log-rank P = .40). Patients with favorable iFISH showed improved PFS (P = .004) and a trend toward a late survival benefit. Patients with adverse iFISH receiving thalidomide showed no significant PFS benefit and worse OS (P = .009). Effective relapse therapy enhanced survival after progression, translating into a significant OS benefit. Meta-analysis of this and other studies show a significant late OS benefit (P < .001, 7-year difference hazard ratio = 12.3; 95% confidence interval, 5.5-19.0). Thalidomide maintenance significantly improves PFS and can be associated with improved OS. iFISH testing is important in assessing the clinical impact of maintenance therapy. Overview analysis demonstrated that thalidomide maintenance was associated with a significant late OS benefit. This trial was registered at www.isrctn.org as #ISRCTN68454111.

Combination of IFN-α/Gm-CSF as a Maintenance Therapy for Multiple Myeloma Patients After Autologous Stem Cell Transplantation (ASCT): A Prospective Phase II Study

Interferon alpha (IFN-α) has been used as a maintenance therapy after autologous stem cell transplantation (ASCT) for multiple myeloma (MM) patients. In this study, we combined GM-CSF with IFN-α in order to improve IFN tolerance in post-ASCT myeloma patients. Primary aims were to evaluate myelotoxicity and effectiveness of this maintenance therapy. The treatment included 4 × 10⁶ units of IFN-α and 125 μg/m² of GM-CSF given three times a week for twelve months. Twenty seven patients were enrolled within 120 days after ASCT. One patient discontinued treatment due to thrombocytopenia and seven others were taken off study due to flu-like symptoms and/or increase in liver enzymes. With a median follow-up of 45.5 months, the median overall survival was not reached while the median progression-free survival was 28 months. Eleven patients (42%) have remained in very good partial remission or complete remission since ASCT. In conclusion, our results demonstrate that maintenance with GM-CSF and IFN-α is safe and effective.

Total marrow irradiation: a new ablative regimen as part of tandem autologous stem cell transplantation for patients with multiple myeloma

PURPOSE

To establish feasibility, maximum tolerated dose (MTD), and potential efficacy of ablative dose total marrow irradiation (TMI) delivered by helical tomotherapy in patients with multiple myeloma (MM).

EXPERIMENTAL DESIGN

Patients with responding or stable MM received tandem autologous stem cell transplants, first with melphalan 200 mg/m(2), and 60 days or later with TMI. TMI doses were to be escalated from 1,000 cGy by increments of 200 cGy. All patients received thalidomide and dexamethasone maintenance.

RESULTS

Twenty-two of 25 enrolled patients (79%) received tandem autologous stem cell transplantation (TASCT): TMI was administered at a median of 63.5 days (44-119) after melphalan. Dose-limiting toxicities at level 5 (1,800 cGy) included reversible grade 3 pneumonitis, congestive heart failure, and enteritis (1), and grade 3 hypotension (1). The estimated median radiation dose to normal organs was 11% to 81% of the prescribed marrow dose. Late toxicities included reversible enteritis (1), and lower extremity deep venous thrombosis during maintenance therapy (2). The complete and very good partial response rates were 55% and 27% following TASCT and maintenance therapy. At a median of 35 months of follow-up (21-50+ months), progression-free and overall survival for all patients were 49% (95% CI, 0.27-0.71) and 82% (0.67-1.00).

CONCLUSION

Ablative dose TMI as part of TASCT is feasible, and the complete response rate is encouraging. Careful monitoring of late toxicities is needed. Further assessment of this modality is justified at the 1,600 cGy MTD level in MM patients who are candidates for ASCT.

Stem cell transplantation for multiple myeloma

PURPOSE OF REVIEW

Autologous stem cell transplantation (SCT) has been an integral part of the management of multiple myeloma, especially for younger patients. During the past decade, several highly effective therapies have become available for treatment of myeloma, raising questions about the role of SCT for its management. This review focuses on recent findings in the context of previous studies demonstrating a benefit for SCT compared with conventional therapies.

RECENT FINDINGS

Recent clinical trials have primarily focused on improving patient outcome by integrating the novel agents into various stages of myeloma therapy, including initial therapy resulting in improvement of disease control at the time of SCT, incorporation into conditioning regimens and finally, using maintenance approaches to prolong the response from SCT. In addition, recent trials also have demonstrated a potential role for tandem SCT in selected patients. However, the role of allogeneic SCT still remains to be better defined.

SUMMARY

Patients with myeloma have more effective choices for therapy today and better outcome. Recent and ongoing trials will allow better selection of therapy, preferably in an individualized fashion, potentially translating into prolonged survival.

The role of high-dose chemotherapy followed by peripheral blood stem cell transplantation for the treatment of multiple myeloma

The management of multiple myeloma has changed significantly over the past 10 years. The results obtained with conventional chemotherapy were disappointing; however the use of high dose therapy (HDT) and stem cell transplantation has significantly improved survival. Autologous, allogeneic and tandem transplantation, along with different conditioning regimens, have been studied in an attempt to optimise and further improve outcomes. This review summarises the role of stem cell transplantation in multiple myeloma. The advent of novel therapies such as thalidomide, lenalidomide and bortezomib have started to redefine the role of peripheral stem cell transplantation, however, further study is needed to better understand how to most effectively use these agents in multiple myeloma in conjunction with HDT.

[New therapeutic strategies for multiple myeloma. Efficacy and cost-effectiveness analyses]

The objective of the present article is the review of the most important therapeutic innovations in the treatment of multiple myeloma in terms of efficacy and cost-effectiveness. Besides autologous transplant with peripheral-blood stem-cell, thalidomide establishes as one of the most powerful therapeutic tools in induction and maintenance treatment and together with lenalidomide and bortezomib as therapy for relapsing/refractory multiple myeloma. Considering, the last named situation thalidomide can be an adequate therapeutical option in combination with dexamethasone. Under a strictly pharmacoeconomic point of view, lenalidomide and bortezomib seem to be additional alternatives in patients previously treated with thalidomide.

Thalidomide maintenance following high-dose therapy in multiple myeloma: a UK myeloma forum phase 2 study

Thalidomide maintenance has unresolved issues regarding dosage and toxicity. We evaluated this in five dose cohorts in 100 patients. At a median follow-up of 32.3 months, 23 patients had stopped thalidomide for disease progression, 54 for side effects. 3-year overall and progression-free survival was 76% and 41% respectively. Dosage did not influence disease outcome but greatly affected toxicity. Fifteen patients converted from partial remission to complete remission on thalidomide at a median of 13.5 months. Maintenance doses >200 mg were largely unachievable and peripheral neuropathy was the main toxicity. Lower doses enabled more patients to stay on the drug for a useful period of time.

High-dose chemotherapy and autologous hematopoietic stem cell transplantation in myeloma patients under the age of 65 years

One or two cycles of high-dose chemotherapy with autologous hematopoietic stem cell transplantation have been shown to improve response rates and survival in myeloma. While this observation has largely been made in patients under the age of 65 years, there is evidence to suggest that the conclusions can be extrapolated to older individuals as well. In contrast to other hematologic malignancies treated with high-dose therapy, autografted myeloma patients continue to relapse several years after transplantation, and few patients are cured with this modality. However, up to a third of patients may be alive beyond a decade; some with excellent quality of life giving rise to the concept of 'operational cure'. Relapsing disease can be treated with novel agents or repeat high-dose chemotherapy and transplantation. The pressing questions to which answers are not obvious at the moment are whether tandem transplantation should be offered to all patients, and whether novel agents should be used before transplantation or reserved for relapse. Despite their excellent activity, there is no evidence so far that novel agents such as thalidomide, bortezomib and lenalidomide can replace high-dose chemotherapy and stem cell transplantation.

Autologous stem cell transplantation in the elderly including pre- and post-treatment options

Multiple myeloma (MM) is a disease of the elderly with a median age at diagnosis of 67 years in a referral population. High-dose chemotherapy (HDT) and autologous stem cell transplantation has been shown to improve survival in patients with MM in randomized trials and remains the preferred option for eligible patients. However, the randomized clinical trials demonstrating an advantage for HDT included only patients younger than 65 years and evidence supporting its role for the elderly patients has been based on retrospective reviews. The introduction of thalidomide, lenalidomide and bortezomib has changed the paradigm for treatment of myeloma and improved the outcome for these patients. Several ongoing clinical trials are evaluating the role of these novel agents in this population, specifically comparing these to HDT-based approaches. Other trials are examining the role of maintenance therapy post-HDT with these novel drugs with or without steroids. The role of HDT will be further redefined in the coming years with improvements in other therapies.

Role of autologous stem cell transplantation in multiple myeloma

High-dose chemotherapy with autologous stem cell transplantation (ASCT) has been shown to improve survival in patients with multiple myeloma in randomized trials and is the standard of care for eligible patients. Recent randomized trials suggest a survival benefit with tandem ASCT, notably for patients failing to achieve a very good response to initial transplantation. Other randomized trials, as well as smaller phase II trials and retrospective studies, have allowed us to improve the process of ASCT in terms of the stem cell collection, conditioning regimens, and extension of the therapy to a wider patient population. The introduction of thalidomide, lenalidomide, and bortezomib have changed the paradigm for treatment of myeloma and significantly improved the outcome for these patients. The role of ASCT will clearly be redefined in the coming years with improvements in other therapies.

Maintenance therapy in multiple myeloma

Therapeutic advances in the treatment of multiple myeloma have significantly improved remission duration and overall survival (OS). These strategies have included the use of immunotherapy (interferon), novel agents (bortezomib, thalidomide, and lenalidomide), corticosteroids, and chemotherapy. While novel agents have had a major impact on response rates with initial therapy, most patients with multiple myeloma will eventually relapse. In the setting of minimal residual disease following standard dose or high-dose therapy, a number of different 'maintenance' strategies have emerged to prolong the duration of initial or subsequent remissions. The impact of these strategies on OS and event-free survival (EFS) is critically important, as the use of ineffective maintenance therapy adds the burden of additional cost, morbidity, and may reduce quality of life. Truly successful maintenance therapy will be effective in the setting of minimal residual disease, and will improve not only EFS, but also OS. This review summarizes the currently available data in the maintenance setting for multiple myeloma, and will discuss potential future trials to further address this important issue.

Low tolerance and high toxicity of thalidomide as maintenance therapy after double autologous stem cell transplant in multiple myeloma patients

Although a double autologous peripheral blood stem cell transplant (APBSCT) is an effective therapy for patients (pts) with multiple myeloma and extends progression-free survival and overall survival, pts show a continued pattern of recurrent disease. The feasibility and tolerability of thalidomide (Thal) administered in the post-transplantation period as maintenance therapy was tested in 17 pts at a dose of 100 mg/d starting between 3 and 5 months after the second transplantation and continuing either until toxicity precluded further therapy or until pts had disease progression. After a median administration of 13 months (range: 3-26), 76.5% (13 pts) failed to tolerate Thal because of: transiet ischemic attack (three pts), severe fatigue (two), neutropenia (one), piastrinopenia (one), severe opportunistic infectious (two), erectile impotence (one), gastrointestinal toxicity (anorexia with weight loss one), peripheral neuropathy (two). After a median follow-up of 36 months (range: 10-59) from the second transplant, 13 patients attained a CR + near CR (with a conversion rate from 47.1% to 76.5%). In conclusion, Thal as maintenance therapy after double ASCT is associated with low feasibility and high toxicity and could prevent a lengthy use of this antineoplastic agent.

Maintenance therapy for multiple myeloma with particular emphasis on thalidomide

Treatment standards are changing as a result of new findings in the therapy of multiple myeloma. So far, prednisone, dexamethasone and interferon-a have mainly been used as maintenance therapy after achieving remission or stable disease. At present, thalidomide is being considered as a new therapeutic option in several studies investigating maintenance therapy. As a result of the dose dependence of adverse effects such as neuropathy, constipation, sedation/vertigo and bradycardia, individual adjustment of the thalidomide dose is recommended. Only isolated cases of thrombosis occurred in the maintenance phase of therapy, and discontinuation of therapy is generally not necessary. While important study results on the efficacy of thalidomide following conventional chemotherapy are still awaited, it is the best documented drug so far for maintenance therapy following autologous stem cell transplantation. An upgrade of the response was seen in 22-73% of patients, as well as a significant prolongation of progression-free survival. For the first time, maintenance therapy with thalidomide showed a significant improvement in overall survival in a phase III study published recently. The tolerability of thalidomide could be further improved by including the option of intermittent administration of the drug.