Sarah A. Holstein

Updated analysis of CALGB (Alliance) 100104 assessing lenalidomide versus placebo maintenance after single autologous stem-cell transplantation for multiple myeloma: a randomised, double-blind, phase 3 trial

BACKGROUND In the CALGB (Alliance) 100104 study, lenalidomide versus placebo after autologous stem-cell transplantation (ASCT) was investigated for patients with newly diagnosed myeloma. That study showed improved time to progression and overall survival and an increase in second primary malignancies for lenalidomide at a median follow-up of 34 months. Here we report an updated intention-to-treat analysis of CALGB (Alliance) 100104 at a median follow-up of 91 months. METHODS Patients were eligible for this randomised, double-blind, placebo-controlled, phase 3 trial if they had symptomatic disease requiring treatment; had received, at most, two induction regimens; and had achieved stable disease or better in the first 100 days after ASCT. We randomly assigned patients to either lenalidomide or placebo groups using permuted block randomisation, with a fixed block size of six. Randomisation was stratified by three factors: normal or elevated β2 microglobulin concentration at registration (≤2·5 mg/L vs >2·5 mg/L), previous use or non-use of thalidomide during induction therapy, and previous use or non-use of lenalidomide during induction therapy. The starting dose was two capsules (10 mg) per day, escalated to three capsules (15 mg) per day after 3 months. The primary endpoint was time to progression (time of progressive disease or death from any cause), with intention-to-treat analysis. This study is registered with ClinicalTrials.gov, identifier NCT00114101. New patients are no longer being recruited, but some patients remain on treatment and in follow-up. FINDINGS Between April 14, 2005, and July 2, 2009, 460 patients were randomly assigned to receive either lenalidomide (n=231) or placebo (n=229). After three interim analyses, the study was unblinded at a median follow-up of 18 months, at which point 86 (67%) of 128 patients without progressive disease in the placebo group chose to cross over to the lenalidomide group. The median follow-up for the updated survival analysis, as of Oct 19, 2016, was 91 months (IQR 83·6-103·1). The median time to progression was 57·3 months (95% CI 44·2-73·3) for the lenalidomide group and 28·9 months (23·0-36·3) for the placebo group (hazard ratio 0·57, 95% CI 0·46-0·71; p<0·0001). The most common grade 3-4 adverse events were neutropenia (116 [50%] patients in the lenalidomide group and 41 [18%] patients in the placebo group) and thrombocytopenia (34 [15%] patients in the lenalidomide group and 12 [5%] patients in the placebo group). 18 (8%) haematological and 14 (6%) solid tumour second primary malignancies were diagnosed after randomisation and before disease progression in the lenalidomide group, compared with three (1%) haematological and nine (4%) solid tumour second primary malignancies in the placebo group. Three haematological and five solid tumour second primary malignancies in the placebo group were in the crossover subgroup. INTERPRETATION Despite an increase in haematological adverse events and second primary malignancies, lenalidomide maintenance therapy after ASCT significantly improved time to progression and could be considered a standard of care. FUNDING The National Cancer Institute.Background CALGB 100104 (Alliance) studied lenalidomide vs. placebo following autologous stem cell transplant (ASCT) for newly diagnosed myeloma patients, demonstrating improved time to progression (TTP) and overall survival (OS), and an increase in second primary malignancies (SPM) for lenalidomide at 34-months median follow-up. Here we report an updated intent-to-treat analysis at 91-months median follow-up. Methods Patients were eligible if they had active myeloma, had received at most two induction regimens and had achieved stable disease or better in the first 100 days after ASCT. In this phase 3 study, 460 patients were randomised in a double-blind manner to either lenalidomide (n=231) or placebo (n=229) utilizing a permutated-block randomisation with fixed block size. Randomisation was stratified by three factors: normal or elevated β2-microglobulin level at registration (≤2·5 mg/L vs > 2·5 mg/L), prior use or nonuse of thalidomide during induction therapy, and prior use or nonuse of lenalidomide during induction therapy. The starting dose was 10 mg daily, escalated to 15 mg daily after three months. The primary endpoint was TTP (time of progressive disease or death from any cause) using intent-to-treat analysis. After three interim analyses, the study was unblinded at median follow-up of 18 months and 86/128 placebo patients without progressive disease chose to cross over to lenalidomide. This study is registered with ClinicalTrials.gov identifier NCT00114101; new patients are no longer being recruited, but some patients remain on treatment and in follow-up. Findings The median TTP for lenalidomide is 57·3 months (95% CI 44·2–73·3) and 28·9 months (95% CI 23·0–36·3) for placebo (hazard ratio (HR): 0·57, 95% CI 0·46–0·71, p<0·0001). The TTP benefit with lenalidomide was observed regardless of whether patients were in a complete response at time of randomisation or whether they had received thalidomide or lenalidomide induction therapy. The most common grade 3–4 adverse events were neutropenia (116 (50%) of 231 patients in the lenalidomide arm and 37 (16%) of 229 patients in the placebo arm) and thrombocytopenia (34 patients (15%) in the lenalidomide arm and 11 patients (4·8%) in the placebo arm. Eighteen haematological (7·8%) and 14 solid tumour (6·1%) SPMs have been diagnosed following randomisation and prior to disease progression in the lenalidomide arm vs. three haematological (1·3%) and nine solid tumour (3·9%) SPMs in the placebo arm. Of the placebo SPMs, three haematological and five of nine solid tumour SPMs were in the crossover subgroup. Interpretation Despite an increase in haematological adverse events and SPMs, lenalidomide maintenance therapy following ASCT significantly improves TTP and can be considered a standard of care.

Immunomodulatory Drugs in Multiple Myeloma: Mechanisms of Action and Clinical Experience

Over the last two decades, the outcomes for patients with multiple myeloma, a plasma cell malignancy, have dramatically improved. The development of the immunomodulatory drugs (IMiDs), which include thalidomide, lenalidomide, and pomalidomide, has contributed significantly to these improved outcomes. While thalidomide is now less commonly prescribed, lenalidomide is widely used in the treatment of newly diagnosed transplant-eligible and transplant-ineligible patients, in the maintenance setting post-transplant and in the relapsed/refractory setting, while pomalidomide is currently utilized in the relapsed/refractory setting. The IMiDs have been reported to have a multitude of activities, including anti-angiogenic, cytotoxic, and immunomodulatory. However, the more recent discoveries that the IMiDs bind to cereblon and thus regulate the ubiquitination of key transcription factors including IKZF1 and IKZF3 have provided greater insight into their mechanism of action. Here, the clinical efficacy of these agents in myeloma is reviewed and the structure-function relationship, the molecular mechanisms of action, and the association of IMiDs with second primary malignancies and thrombosis are discussed.

Olefin Isomers of a Triazole Bisphosphonate Synergistically Inhibit Geranylgeranyl Diphosphate Synthase

The isoprenoid donor for protein geranylgeranylation reactions, geranylgeranyl diphosphate (GGDP), is the product of the enzyme GGDP synthase (GGDPS) that condenses farnesyl diphosphate (FDP) and isopentenyl pyrophosphate. GGDPS inhibition is of interest from a therapeutic perspective for multiple myeloma because we have shown that targeting Rab GTPase geranylgeranylation impairs monoclonal protein trafficking, leading to endoplasmic reticulum stress and apoptosis. We reported a series of triazole bisphosphonate GGDPS inhibitors, of which the most potent was a 3:1 mixture of homogeranyl (HG) and homoneryl (HN) isomers. Here we determined the activity of the individual olefin isomers. Enzymatic and cellular assays revealed that although HN is approximately threefold more potent than HG, HN is not more potent than the original mixture. Studies in which cells were treated with varying concentrations of each isomer alone and in different combinations revealed that the two isomers potentiate the induced-inhibition of protein geranylgeranylation when used in a 3:1 HG:HN combination. A synergistic interaction was observed between the two isomers in the GGDPS enzyme assay. These results suggested that the two isomers bind simultaneously to the enzyme but within different domains. Computational modeling studies revealed that HN is preferred at the FDP site, that HG is preferred at the GGDP site, and that both isomers may bind to the enzyme simultaneously. These studies are the first to report a set of olefin isomers that synergistically inhibit GGDPS, thus establishing a new paradigm for the future development of GGDPS inhibitors.

Bishomoisoprenoid triazole bisphosphonates as inhibitors of geranylgeranyl diphosphate synthase

Protein geranylgeranylation reactions are dependent on the availability of geranylgeranyl diphosphate (GGDP), which serves as the isoprenoid donor. Inhibition of GGDP synthase (GGDPS) is of interest from a drug development perspective as GGDPS inhibition results in impaired protein geranylgeranylation, which in multiple myeloma, disrupts monoclonal protein trafficking and induces apoptosis. We have recently reported a series of isoprenoid triazole bisphosphonates and have demonstrated that a 3:1 mixture of homogeranyl and homoneryl isomers potently, and in a synergistic manner, inhibits GGDPS. We now present the synthesis and biological evaluation of a novel series of bishomoisoprenoid triazoles which furthers our understanding of the structure-function relationship of this class. These studies demonstrate the importance of chain length and olefin stereochemistry on inhibitory activity.

Update on the role of lenalidomide in patients with multiple myeloma

Lenalidomide is a derivative of thalidomide and belongs to the class of drugs known as the immunomodulatory drugs (IMiDs). The IMiDs have played a large role in improving the survival outcomes of patients with multiple myeloma. In particular, lenalidomide is currently standard of care in the newly diagnosed setting, in the maintenance setting post-autologous stem cell transplant, as well as in the relapsed/refractory setting. While the combination of lenalidomide and various proteasome inhibitors has proven particularly effective, there are emerging data demonstrating the effectiveness of lenalidomide in combination with other important classes of drugs including the monoclonal antibodies. Recent studies have provided insight into the molecular target of lenalidomide and the other IMiDs, although there is still much to be learned regarding the mechanisms by which lenalidomide affects the myeloma cell and the immune system. Here we review the molecular mechanisms of action, side effects, and the results of the clinical trials which have led to the widespread incorporation of lenalidomide into the myeloma therapeutic armamentarium.

Quantitative determination of a potent geranylgeranyl diphosphate synthase inhibitor using LC–MS/MS: Derivatization and application

HighlightsA LC–MS/MS for quantitation of VSW1198 in mouse plasma and tissues.Highly sensitive and stable derivatized compounds were analyzed by LC–MS/MS.This approach could be applied to other structurally similar bisphosphonates. Abstract An isomeric mixture of homogeranyl/homoneryl triazole bisphosphonates (VSW1198) has previously been shown to be a potent inhibitor of geranylgeranyl diphosphate (GGDP) synthase (GGDPS) and of therapeutic interest for the treatment of multiple myeloma. We have developed and validated a selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) method for the simultaneous quantitation of both the E‐ and Z‐ isomers of VSW1198 in cell culture media, mouse plasma and tissues. VSW1198 and internal standard are extracted from the bio‐matrices by solid‐phase extraction, followed by derivatization using trimethylsilyldiazomethane. The chromatographic separation of analytes was achieved on a Phenomenex Gemini NX column (150 mm * 2.0 mm, 5 &mgr;) with gradient elution using 0.1% acetic acid and methanol/acetonitrile (1:1) as the mobile phase at a flow rate of 0.2 mL/min. Derivatized analytes were ionized with an electrospray ionization source in positive multiple reaction monitoring (MRM) mode and quantitated using MS/MS. The MS/MS response was linear over the concentration range from 0.38–1500 and 0.13–500 ng/mL for the E‐ and Z‐isomers, respectively. The within‐ and between‐day precision (relative standard deviation, % RSD) and accuracy were within the acceptable limits per FDA guidelines. The validated method was used for quantitative determination of the compounds in preclinical studies focused on the development of VSW1198 as a novel anti‐cancer agent.

Maintenance Treatment and Survival in Patients With Myeloma: A Systematic Review and Network Meta-analysis

Importance Several trials demonstrated the impact of novel agent-based maintenance in newly diagnosed multiple myeloma (NDMM), but there is no current evidence demonstrating the superiority of one regimen over the other, owing to the lack of direct/indirect comparisons. Objective To analyze and compare the effectiveness of different maintenance regimens in NDMM via a network meta-analysis. Data Sources We performed 2 independent searches in PubMed and Cochrane databases, and then we identified all the records registered after 1999 and on or before November 20, 2017. Study Selection By blinded review, we identified prospective phase 3 randomized trials evaluating novel agent-based maintenance in patients with NDMM; the included studies compared at least 2 maintenance approaches; comparators included placebo and no maintenance. From 364 screened records, 11 studies were included. Data Extraction and Synthesis We followed (independent extraction) the guidelines provided by the PRISMA Report and the EQUATOR Network. The evidence was synthesized using a network meta-analysis (NMA). To allow comparison of all treatments, no maintenance was selected as common comparator and the effect of placebo was assumed to be the same as no treatment. The best option was identified by a Bayesian consistency model based on hazard ratio (HR), 95% credible interval (CrI), probability of being the best treatment (PbBT), and median ranking distribution (MedR). Main Outcomes and Measures Outcomes of interest were progression-free survival (PFS) and overall survival (OS). Results Eleven trials and 8 treatments including a total of 5073 participants were included. By PFS analysis, lenalidomide-based regimens (lenalidomide-prednisone, lenalidomide alone) were identified as the most effective options (HR, 0.39 [95% CrI, 0.28-0.53] and 0.47 [95% CrI, 0.39-0.55], respectively; MedR, 1 and 2; overall PbBT, 74%). Four treatments (thalidomide-interferon, thalidomide-bortezomib, bortezomib-prednisone, thalidomide alone) showed an HR in favor of maintenance. By OS analysis, lenalidomide alone was identified as the best option (HR, 0.76; 95% CrI, 0.51-1.16; MedR, 2; PbBT, 38%), followed by bortezomib-thalidomide and bortezomib-prednisone. Similar features were noticed in the restricted network including transplant trials, in the sensitivity analysis, and in most of the prognostic subgroups. Conclusions and Relevance Based on PFS and OS results of this NMA, lenalidomide maintenance appears to be the best treatment option, by synthesizing the available evidence of novel agent-based maintenance in the past 20 years.

Methods to prevent and treat relapse after hematopoietic stem cell transplantation with tyrosine kinase inhibitors, immunomodulating drugs, deacetylase inhibitors, and hypomethylating agents

Relapse is a major cause of treatment failure after stem cell transplantation. Novel agents given as maintenance or preemptive post transplant were discussed at the 3rd International Workshop on Biology, Prevention, and Treatment of Relapse after Stem Cell Transplantation in Hamburg/Germany in November 2016 under the auspices of EBMT and ASBMT. Maintenance therapy is started after SCT without detectable disease, while preemptive therapy is triggered by the detection of minimal residual disease (MRD). The maintenance approach treats all patients, and overtreats a significant amount. Maintenance therapy requires an agent without significant off-target toxicity. The preemptive approach only initiates therapy upon detection of MRD, while sparing further therapy to those who remain in remission. Preemptive strategies require sensitive and clinically reliable assays to detect MRD. Here current development of tyrosine kinase inhibitors (TKIs) immunomodulating drugs (IMiDs), deacetylase inhibitors, and hypomethylating agents were reviewed.

Immune signatures associated with improved progression-free and overall survival for myeloma patients treated with AHSCT

Multiple therapeutic options exist for multiple myeloma (MM), including autologous hematopoietic stem cell transplantation (AHSCT). Measurement of minimal residual disease (MRD) and immune reconstitution is rapidly becoming an integral part of the care of MM patients. We investigated comprehensive immune profiling (IP) associated with progression-free survival (PFS) and overall survival (OS). From August 2007 to January 2014, 101 consecutive MM patients underwent peripheral blood IP and marrow MRD testing before and approximately 100 days after AHSCT. Higher pre-AHSCT CD19+ B-cell counts correlated with improved 2-year PFS (83% [highest quartile] vs 53% [lowest quartile]; P = .01) and OS (93% [highest quartile] vs 63% [lowest quartile]; P = .0003). This effect was seen primarily in patients with MRD-positive marrow tests. Higher γδ T-cell counts post-AHSCT correlated with improved 2-year PFS (65% [highest quartile] vs 45% [lowest quartile]; P = .02) and OS (89% [highest quartile] vs 65% [lowest quartile]; P = .01). Higher CD4+ central memory (CM) cell counts post-AHSCT were associated with improved 2-year OS (95% [upper quartile] vs 47% [lowest quartile]; P = .0003) but not PFS. The higher γδ T-cell and CD4+ CM-cell count associations were primarily observed in MRD-negative patients post-AHSCT and in patients not receiving maintenance therapy. This proof-of-concept study demonstrates that IP before and after AHSCT can be of complementary prognostic value for depth of response. Maintenance therapy seems to overcome negative IP. IP and MRD should be measured in clinical trials of maintenance therapy with novel agents post-AHSCT for MM to confirm their utility for prognosis and management.

BMT CTN Myeloma Intergroup Workshop on Minimal Residual Disease and Immune Profiling: Summary and Recommendations From the Organizing Committee

The Blood and Marrow Transplant Clinical Trials Network Myeloma Intergroup Workshop on Minimal Residual Disease and Immune Profiling was convened on December 1, 2016 at the American Society of Hematology meeting to discuss the emerging data and technologies for minimal residual disease assessment and immune profiling in myeloma. Particular emphasis was placed on developing strategies to incorporate these techniques into clinical trial design. This document reviews the literature, summarizes the topics discussed in the workshop, and provides recommendations for integration of these techniques into future clinical trial design.