Multiple drug combinations of bortezomib, lenalidomide, and thalidomide for first-line treatment in adults with transplant-ineligible multiple myeloma: a network meta-analysis

BACKGROUND

Multiple myeloma is a bone marrow-based hematological malignancy accounting for approximately two per cent of cancers. First-line treatment for transplant-ineligible individuals consists of multiple drug combinations of bortezomib (V), lenalidomide (R), or thalidomide (T). However, access to these medicines is restricted in many countries worldwide.

OBJECTIVES

To assess and compare the effectiveness and safety of multiple drug combinations of V, R, and T for adults with newly diagnosed transplant-ineligible multiple myeloma and to inform an application for the inclusion of these medicines into the World Health Organization's (WHO) list of essential medicines.

SEARCH METHODS

We searched CENTRAL and MEDLINE, conference proceedings and study registries on 14 February 2019 for randomised controlled trials (RCTs) comparing multiple drug combinations of V, R and T for adults with newly diagnosed transplant-ineligible multiple myeloma.

SELECTION CRITERIA

We included RCTs comparing combination therapies of V, R, and T, plus melphalan and prednisone (MP) or dexamethasone (D) for first-line treatment of adults with transplant-ineligible multiple myeloma. We excluded trials including adults with relapsed or refractory disease, trials comparing drug therapies to other types of therapy and trials including second-generation novel agents.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias of included trials. As effect measures we used hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) and risk ratios (RRs) for adverse events. An HR or RR < 1 indicates an advantage for the intervention compared to the main comparator MP. Where available, we extracted quality of life (QoL) data (scores of standardised questionnaires). Results quoted are from network meta-analysis (NMA) unless stated.

MAIN RESULTS

We included 25 studies (148 references) comprising 11,403 participants and 21 treatment regimens. Treatments were differentiated between restricted treatment duration (treatment with a pre-specified amount of cycles) and continuous therapy (treatment administered until disease progression, the person becomes intolerant to the drug, or treatment given for a prolonged period). Continuous therapies are indicated with a "c". Risk of bias was generally high across studies due to the open-label study design. Overall survival (OS) Evidence suggests that treatment with RD (HR 0.63 (95% confidence interval (CI) 0.40 to 0.99), median OS 55.2 months (35.2 to 87.0)); TMP (HR 0.75 (95% CI 0.58 to 0.97), median OS: 46.4 months (35.9 to 60.0)); and VRDc (HR 0.49 (95% CI 0.26 to 0.92), median OS 71.0 months (37.8 to 133.8)) probably increases survival compared to median reported OS of 34.8 months with MP (moderate certainty). Treatment with VMP may result in a large increase in OS, compared to MP (HR 0.70 (95% CI 0.45 to 1.07), median OS 49.7 months (32.5 to 77.3)), low certainty). Progression-free survival (PFS) Treatment withRD (HR 0.65 (95% CI0.44 to 0.96), median PFS: 24.9 months (16.9 to 36.8)); TMP (HR 0.63 (95% CI 0.50 to 0.78), median PFS:25.7 months (20.8 to 32.4)); VMP (HR 0.56 (95% CI 0.35 to 0.90), median PFS: 28.9 months (18.0 to 46.3)); and VRDc (HR 0.34 (95% CI 0.20 to 0.58), median PFS: 47.6 months (27.9 to 81.0)) may result in a large increase in PFS (low certainty) compared to MP (median reported PFS: 16.2 months). Adverse events The risk of polyneuropathies may be lower with RD compared to treatment with MP (RR 0.57 (95% CI 0.16 to 1.99), risk for RD: 0.5% (0.1 to 1.8), mean reported risk for MP: 0.9% (10 of 1074 patients affected), low certainty). However, the CIs are also compatible with no difference or an increase in neuropathies. Treatment with TMP (RR 4.44 (95% CI1.77 to 11.11), risk: 4.0% (1.6 to 10.0)) and VMP (RR 88.22 (95% CI 5.36 to 1451.11), risk: 79.4% (4.8 to 1306.0)) probably results in a large increase in polyneuropathies compared to MP (moderate certainty). No study reported the amount of participants with grade ≥ 3 polyneuropathies for treatment with VRDc. VMP probably increases the proportion of participants with serious adverse events (SAEs) compared to MP (RR 1.28 (95% CI 1.06 to 1.54), risk for VMP: 46.2% (38.3 to 55.6), mean risk for MP: 36.1% (177 of 490 patients affected), moderate certainty). RD, TMP, and VRDc were not connected to MP in the network and the risk of SAEs could not be compared. Treatment with RD (RR 4.18 (95% CI 2.13 to 8.20), NMA-risk: 38.5% (19.6 to 75.4)); and TMP (RR 4.10 (95% CI 2.40 to 7.01), risk: 37.7% (22.1 to 64.5)) results in a large increase of withdrawals from the trial due to adverse events (high certainty) compared to MP (mean reported risk: 9.2% (77 of 837 patients withdrew)). The risk is probably slightly increased with VMP (RR 1.06 (95% CI 0.63 to 1.81), risk: 9.75% (5.8 to 16.7), moderate certainty), while it is much increased with VRDc (RR 8.92 (95% CI 3.82 to 20.84), risk: 82.1% (35.1 to 191.7), high certainty) compared to MP. Quality of life QoL was reported in four studies for seven different treatment regimens (MP, MPc, RD, RMP, RMPc, TMP, TMPc) and was measured with four different tools. Assessment and reporting differed between studies and could not be meta-analysed. However, all studies reported an improvement of QoL after initiation of anti-myeloma treatment for all assessed treatment regimens.

AUTHORS' CONCLUSIONS

Based on our four pre-selected comparisons of interest, continuous treatment with VRD had the largest survival benefit compared with MP, while RD and TMP also probably considerably increase survival. However, treatment combinations of V, R, and T also substantially increase the incidence of AEs, and lead to a higher risk of treatment discontinuation. Their effectiveness and safety profiles may best be analysed in further randomised head-to-head trials. Further trials should focus on consistent reporting of safety outcomes and should use a standardised instrument to evaluate QoL to ensure comparability of treatment-combinations.

Bortezomib-Dexamethasone or Vincristine-Doxorubicin-Dexamethasone as Induction Therapy Followed by Thalidomide as Maintenance Therapy in Untreated Multiple Myeloma Patients

This randomized, retrospective study evaluated the effect of thalidomide combined with bortezomib-dexamethasone (TBD) or vincristine-doxorubicin-dexamethasone (T-VAD) on 46 patients with multiple myeloma. Newly diagnosed patients were randomly allocated to receive TBD ( n = 24) or T-VAD ( n = 22). The high-quality response rate (complete response plus very good partial response) was 62.5% in the TBD group and 45.4% for T-VAD. The complete response rate was 29.2% for TBD and 13.6% for T-VAD. Overall survival at 2 and 3 years, respectively, was 91.7% and 62.5% for TBD versus 86.4% and 54.5% for T-VAD. Most of the toxic effects of treatment were well tolerated. Both regimens were effective in the treatment of newly diagnosed multiple myeloma patients. Further studies are required to determine the role of thalidomide in these two regimens.

Newly diagnosed multiple myeloma in Taiwan: the evolution of therapy, stem cell transplantation and new treatment agents

Multiple myeloma is a clonal plasma cell dyscrasia with clinical heterogeneity. As of now, two key questions need to be answered before starting to treat a newly diagnosed myeloma patient. One is whether the patient is a candidate for high-dose chemotherapy with stem cell support and the other is risk stratification. As novel therapeutics have emerged, it is increasingly important to introduce a risk-adapted approach. The heterogeneity of the disease is established, for the most part, by disease biology, predominantly genetics. Cytogenetic analysis by either banding technique or fluorescent in situ hybridization is able to identify high-risk subpopulations. The new international staging system based on beta2-microglobulin and albumin levels in serum is also very helpful in defining the high-risk group (stage 3). This group of patients may not respond well to high-dose chemotherapy and require early introduction of newer treatments such as the bortezomib-containing regimen. The main factor in determining the eligibility for stem cell transplants is age. Based on the current literature and situation in Taiwan, we suggest stem cell transplantation if the patient is younger than 55 years of age. Each case should be considered individually if the age of the patient is between 55 and 70 years. Finally, we have also reviewed the status and the treatment of multiple myeloma in Taiwan. Fortunately, there has been an improvement in awareness, diagnosis and treatment. Cytogenetic studies have been applied in risk evaluations, but are limited in a few centers due to lack of availability. With the exception of the agent lenalidomide, new novel agents are available for treating of myeloma in Taiwan.

Multiple myeloma: biology, standard therapy, and transplant therapy

The understanding of the pathogenesis of multiple myeloma has undergone a major transformation over the past eight years. New insights into the microenvironment of the plasma cell as well as elucidation of signaling pathways that prevent plasma cell apoptosis are leading to rapid new drug development. The introduction of novel agents has led to a significant increase in survival. Combinations of novel agents are expected to provide higher complete response rate with anticipated prolongation of relapse free and overall survival. Autologous and allogeneic stem cell transplantation remains an integral part of therapy further improving the outcomes following induction with novel agents.

Thalidomide-dexamethasone compared with melphalan-prednisolone in elderly patients with multiple myeloma

We compared thalidomide-dexamethasone (TD) with melphalan-prednisolone (MP) in 289 elderly patients with multiple myeloma (MM). Patients received either thalidomide 200 mg plus dexamethasone 40 mg, days 1 to 4 and 15 to 18 on even cycles and days 1 to 4 on odd cycles, during a 28-day cycle or to melphalan 0.25 mg/kg and prednisolone 2 mg/kg orally on days 1 to 4 during a 28- to 42-day cycle. Patients achieving stable disease or better were randomly assigned to maintenance therapy with either thalidomide 100 mg daily and 3 MU interferon alpha-2b thrice weekly or to 3 MU interferon alpha-2b thrice weekly only. TD resulted in a higher proportion of complete and very good remissions (26% vs 13%; P= .006) and overall responses (68% vs 50%; P= .002) compared with MP. Time to progression (21.2 vs 29.1 months; P= .2), and progression-free survival was similar (16.7 vs 20.7 months; P= .1), but overall survival was significantly shorter in the TD group (41.5 vs 49.4 months; P= .024). Toxicity was higher with TD, particularly in patients older than 75 years with poor performance status. The study was registered at ClinicalTrials.gov as NCT00205751.

Multiple myeloma--an update on diagnosis and treatment

Multiple myeloma is a plasma cell (PC) malignancy characterized by the accumulation of monoclonal PCs in the bone marrow and the production of large amounts of a monoclonal immunoglobulin or paraprotein. In the past years, new approaches in the diagnosis and treatment were introduced aiming to identify high-risk patients who need proper anti-myeloma treatment. Intensive therapy including autologous hematopoietic stem cell transplantation and the new agents bortezomib, thalidomide, and lenalidomide have improved patients' responses. Further optimalization of the different treatment schedules in well-defined patient groups may prolong their survival. Patient stratification is currently based on patient characteristics, extent of myeloma disease, and associated cytogenetic and laboratory anomalies. More and more gene expression studies are introduced to stratify patients and to individualize therapy.

Treatment of newly diagnosed multiple myeloma

Multiple myeloma (MM) is the second most common oncohematologic disease. Most patients are older than 65 years at diagnosis, and different therapeutic options are available depending on the age of the patient. For those younger than 65 years, autologous stem cell transplantation is the standard of care, whereas in older patients the better choice is conventional chemotherapy. The introduction of thalidomide, bortezomib, and lenalidomide, which target MM cells and the bone marrow microenvironment, has changed the therapeutic options in newly diagnosed patients with MM.

Multiple myeloma

Multiple myeloma is a clonal plasma cell malignancy that accounts for slightly more than 10% of all hematologic cancers. In this paper, we present a historically focused review of the disease, from the description of the first case in 1844 to the present. The evolution of drug therapy and stem-cell transplantation for the treatment of myeloma, as well as the development of new agents, is discussed. We also provide an update on current concepts of diagnosis and therapy, with an emphasis on how treatments have emerged from a historical perspective after certain important discoveries and the results of experimental studies.

Thalidomide in the treatment of multiple myeloma

Thalidomide--either alone or in combination with dexamethasone or chemotherapy--has shown significant activity in relapsed/refractory disease. When used in the induction regimens in untreated patients, it significantly increases the response rates as well progression-free survival. Moreover, thalidomide as a maintenance therapy has become a very attractive option. However, the toxicity profile of the drug, mainly neurotoxicity and thrombotic events, mandate careful monitoring of patients treated with thalidomide, whether as the first line, in the relapsed setting, or as maintenance. In this chapter we will review the pharmacology, mechanisms of action, and toxicity of the drug, and will focus on available data from clinical experience and randomized trials of thalidomide in the different settings of multiple myeloma: refractory/relapsed disease, upfront treatment in patients who are eligible for high-dose therapy as well as those who are not, and finally the use of thalidomide as a maintenance treatment.

Frontline treatment in multiple myeloma patients not eligible for stem-cell transplantation

Melphalan-prednisone-thalidomide (MPT) currently appears to be the treatment of choice for a large proportion of elderly patients ineligible for autologous stem-cell transplantation (ASCT). It seems certain that in the near future melphalan-prednisone-Velcade (MPV) and melphalan-prednisone-lenalidomide (MPR) will also be proved superior to melphalan-prednisone (MP), thus providing three therapeutic options (MPT, MPV and MPR) in this patient group with multiple myeloma (MM). These therapeutic options could lead to more personalized treatment approaches, based on patient comorbidities, as the three novel therapies have somewhat different toxicity profiles. MP would be appropriate for only a minority of patients with poor performance status and/or significant comorbidities, such as severe neuropathy or a contraindication to anticoagulants. Questions regarding the relative efficacy of melphalan-based regimens versus dexamethasone-based regimens (preferably with low-dose dexamethasone) will require randomized phase-III trials. More intensive approaches with new drug combinations or with the incorporation of polyethylene glycolated (PEGylated) liposomal doxorubicin will also require additional studies. Additionally, the important issue of maintenance treatment needs to be further investigated, especially in elderly patients.

Melphalan and prednisone plus thalidomide versus melphalan and prednisone alone or reduced-intensity autologous stem cell transplantation in elderly patients with multiple myeloma (IFM 99-06): a randomised trial

BACKGROUND

In multiple myeloma, combination chemotherapy with melphalan plus prednisone is still regarded as the standard of care in elderly patients. We assessed whether the addition of thalidomide to this combination, or reduced-intensity stem cell transplantation, would improve survival.

METHODS

Between May 22, 2000, and Aug 8, 2005, 447 previously untreated patients with multiple myeloma, who were aged between 65 and 75 years, were randomly assigned to receive either melphalan and prednisone (MP; n=196), melphalan and prednisone plus thalidomide (MPT; n=125), or reduced-intensity stem cell transplantation using melphalan 100 mg/m2 (MEL100; n=126). The primary endpoint was overall survival. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00367185.

FINDINGS

After a median follow-up of 51.5 months (IQR 34.4-63.2), median overall survival times were 33.2 months (13.8-54.8) for MP, 51.6 months (26.6-not reached) for MPT, and 38.3 months (13.0-61.6) for MEL100. The MPT regimen was associated with a significantly better overall survival than was the MP regimen (hazard ratio 0.59, 95% CI 0.46-0.81, p=0.0006) or MEL100 regimen (0.69, 0.49-0.96, p=0.027). No difference was seen for MEL100 versus MP (0.86, 0.65-1.15, p=0.32).

INTERPRETATION

The results of our trial provide strong evidence to indicate that the use of thalidomide in combination with melphalan and prednisone should, at present, be the reference treatment for previously untreated elderly patients with multiple myeloma.

Current Standards for First-Line Therapy of Multiple Myeloma

Current standards of care for first-line treatment of multiple myeloma are evolving rapidly because of the introduction of regimens based on novel agents with unique mechanisms of action: the proteasome inhibitor bortezomib and the immunomodulatory drugs thalidomide and lenalidomide. These regimens are becoming increasingly widely used, offering substantially greater benefit to patients in terms of higher response rates and, more importantly, prolonged response durations and survival compared with established standard first-line treatment strategies. A notable aspect of many of these emerging treatment options is the very high rates of complete response (CR) reported, previously only seen with transplantation-based strategies. Achievement of CR is prognostic for improved overall survival; therefore, the higher rates and quality of responses seen with the new regimens might substantially improve patient outcomes versus established standards of care. For example, addition of each of the 3 novel agents to melphalan/prednisone results in higher overall response rates and CR rates, as well as prolonged progression-free and overall survival, compared with melphalan/prednisone alone. Similar substantial improvements in response are seen with addition of the 3 agents to single-agent dexamethasone and the use of bortezomib or thalidomide in VAD (vincristine/doxorubicin/dexamethasone)-like regimens, as induction therapies before stem cell transplantation and in patients not proceeding to transplantation. Ultimately, these novel regimens might obviate the need for stem cell transplantation in a sizeable proportion of patients. The emergence of these new therapeutic options appears likely to significantly alter the first-line treatment paradigm for patients with multiple myeloma.