Lenalidomide in multiple myeloma: Current status and future potential

Lenalidomide use in multiple myeloma (Review)

Lenalidomide is a second-generation new immunomodulatory medication used to treat multiple myeloma (MM). Its mechanism of action involves affecting the expression of vascular endothelial growth factor, interleukin-6, cytochrome c, caspase-8, as well as other factors including immunological modulation and the direct killing of cells, among others, rendering it a fundamental medication, useful for the treatment of MM. Combining lenalidomide with other medications such dexamethasone, bortezomib, ixazomib, carfilzomib and daratumumab can markedly alleviate MM. When autologous-hematopoietic stem cell transplantation (ASCT) cannot be utilized to treat newly diagnosed individuals with MM (NDMM), monotherapy maintenance following lenalidomide and dexamethasone may be employed. Following ASCT, single-agent maintenance with lenalidomide can be performed as an additional treatment. The combination of bortezomib and lenalidomide has been demonstrated to be associated with favorable response rates, tolerable toxicity, and therapeutic benefits although caution is warranted to prevent the onset of peripheral neuropathy with its use. A new-generation oral drug with an excellent safety profile, ixazomib, is more practical and therapeutically applicable in relapsed refractory MM. However, the frequent occurrence of cardiovascular events, hematocrit, and infections with it require flexible adjustment in its clinical application. Carfilzomib produces a rapid and profound response in patients with NDMM eligible for transplantation, but its cardiovascular side effects need to be closely monitored. The primary aim of the present review was to examine the pharmacological properties and pharmacokinetics of lenalidomide, as well as the efficacy and safety of lenalidomide-based treatments with reference to data from clinical trials and real-world studies.

The progress of novel strategies on immune-based therapy in relapsed or refractory diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) can be cured with standard front-line immunochemotherapy, whereas nearly 30-40% of patients experience refractory or relapse. For several decades, the standard treatment strategy for fit relapsed/refractory (R/R) DLBCL patients has been high-dose chemotherapy followed by autologous hematopoietic stem cell transplant (auto-SCT). However, the patients who failed in salvage treatment or those ineligible for subsequent auto-SCT have dismal outcomes. Several immune-based therapies have been developed, including monoclonal antibodies, antibody-drug conjugates, bispecific T-cell engaging antibodies, chimeric antigen receptor T-cells, immune checkpoint inhibitors, and novel small molecules. Meanwhile, allogeneic SCT and radiotherapy are still necessary for disease control for fit patients with certain conditions. In this review, to expand clinical treatment options, we summarize the recent progress of immune-related therapies and prospect the future indirections in patients with R/R DLBCL.

Extracellular Vesicles Isolated from Plasma of Multiple Myeloma Patients Treated with Daratumumab Express CD38, PD-L1, and the Complement Inhibitory Proteins CD55 and CD59

Daratumumab (DARA) has improved the outcome of treatment of multiple myeloma (MM). DARA acts via complement-dependent and -independent mechanisms. Resistance to DARA may result from upregulation of the complement inhibitory proteins CD55 and CD59, downregulation of the DARA target CD38 on myeloma cells or altered expression of the checkpoint inhibitor ligand programmed death ligand-1 (PD-L1) or other mechanisms. In this study, EVs were isolated from peripheral blood (PB) and bone marrow (BM) from multiple myeloma (MM) patients treated with DARA and PB of healthy controls. EV size and number and the expression of CD38, CD55, CD59 and PD-L1 as well as the EV markers CD9, CD63, CD81, CD147 were determined by flow cytometry. Results reveal that all patient EV samples express CD38, PD-L1, CD55 and CD59. The level of CD55 and CD59 are elevated on MM PB EVs compared with healthy controls, and the level of PD-L1 on MM PB EVs is higher in patients responding to treatment with DARA. CD147, a marker of various aspects of malignant behaviour of cancer cells and a potential target for therapy, was significantly elevated on MM EVs compared with healthy controls. Furthermore, mass spectrometry data suggests that MM PB EVs bind DARA. This study reveals a MM PB and BM EV protein signature that may have diagnostic and prognostic value.

Successful treatment with daratumumab, lenalidomide, and dexamethasone therapy followed by autologous stem cell transplantation for newly diagnosed polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome: a case report

BACKGROUND

Transplant-eligible patients with polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome are treated with induction therapy and autologous stem cell transplantation. Conventional induction therapies may exacerbate neuropathy and a high rate of disease progression within 5 years. Furthermore, only 50% of patients are able to walk independently after the therapies. Daratumumab, lenalidomide, and dexamethasone therapy has been reported as a less neurotoxic, highly effective therapy for patients with polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome who are ineligible for transplant or whose syndrome is relapsed/refractory, but no reports have provided data from untreated transplant-eligible patients.

CASE PRESENTATION

A 34-year-old Japanese woman displayed weakness, pain and edema in the lower limbs, decreased grip strength, amenorrhea, and abdominal distention. She was unable to walk independently. The patient was diagnosed with polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome and performed four courses of daratumumab, lenalidomide, and dexamethasone therapy, which enabled her to walk independently and did not exacerbate the neuropathy. Hematopoietic stem cells were collected using plerixafor and filgrastim in combination. Autologous stem cell transplantation was performed with high-dose melphalan. At 3-month post-transplantation follow-up, most of her clinical symptoms had disappeared.

CONCLUSIONS

Daratumumab, lenalidomide, and dexamethasone therapy followed by autologous stem cell transplantation may be more effective than conventional therapy for newly diagnosed polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome. Although there was concerns that daratumumab, lenalidomide, and dexamethasone therapy might lead to poor mobilization of hematopoietic stem cells, this was overcome with the combination of plerixafor and filgrastim. The benefit of daratumumab, lenalidomide, and dexamethasone as induction therapy prior to autologous stem cell transplantation should be confirmed in future clinical trials.

Review of treatment and therapeutic targets in brain arteriovenous malformation

Brain arteriovenous malformations (bAVM) are an important cause of intracranial hemorrhage (ICH), especially in younger patients. The pathogenesis of bAVM are largely unknown. Current understanding of bAVM etiology is based on studying genetic syndromes, animal models, and surgically resected specimens from patients. The identification of activating somatic mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene and other mitogen-activated protein kinase (MAPK) pathway genes has opened up new avenues for bAVM study, leading to a paradigm shift to search for somatic, de novo mutations in sporadic bAVMs instead of focusing on inherited genetic mutations. Through the development of new models and understanding of pathways involved in maintaining normal vascular structure and functions, promising therapeutic targets have been identified and safety and efficacy studies are underway in animal models and in patients. The goal of this paper is to provide a thorough review or current diagnostic and treatment tools, known genes and key pathways involved in bAVM pathogenesis to summarize current treatment options and potential therapeutic targets uncovered by recent discoveries.

Increased Risk of Ischemic Stroke in Multiple Myeloma Associated With Lenalidomide Treatment: A Case Report and Review of the Literature

OBJECTIVE

The aim of the study was to illustrate the increased risk of ischemic stroke in the context of multiple myeloma (MM) under treatment with lenalidomide combined with dexamethasone.

METHODS

This is a case report and literature review.

RESULTS

A 62-year-old woman diagnosed with relapsed MM under treatment with lenalidomide and dexamethasone presented with acute onset disorientation, disturbed behavior, and aphasia. Cranial computed tomography scan revealed an acute cerebral infarction in the left middle cerebral artery territory, and brain magnetic resonance imaging showed additional silent ischemic lesions in other arterial territories. Common stroke etiologies were excluded after an extensive study, leading to a final diagnosis of cerebral infarction of uncommon cause probably related to MM and treatment with lenalidomide plus dexamethasone. A literature review provided 84 reports from the license holder, 2 more cases of stroke in patients with MM receiving lenalidomide and a recurrent stroke in a patient experiencing polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS syndrome) treated with lenalidomide.

CONCLUSIONS

Our case exemplifies the need to raise awareness about the risk of ischemic stroke associated with MM that might be increased by treatment with lenalidomide and to establish consistent recommendations regarding thromboprophylaxis to reduce comorbidities and mortality in these patients.

Thalidomide Reduces Hemorrhage of Brain Arteriovenous Malformations in a Mouse Model

BACKGROUND AND PURPOSE

Brain arteriovenous malformation (bAVM) is an important risk factor for intracranial hemorrhage. Current treatments for bAVM are all associated with considerable risks. There is no safe method to prevent bAVM hemorrhage. Thalidomide reduces nose bleeding in patients with hereditary hemorrhagic telangiectasia, an inherited disorder characterized by vascular malformations. In this study, we tested whether thalidomide and its less toxic analog, lenalidomide, reduce bAVM hemorrhage using a mouse model.

METHODS

bAVMs were induced through induction of brain focal activin-like kinase 1 (Alk1, an AVM causative gene) gene deletion and angiogenesis in adult Alk1-floxed mice. Thalidomide was injected intraperitoneally twice per week for 6 weeks, starting either 2 or 8 weeks after AVM induction. Lenalidomide was injected intraperitoneally daily starting 8 weeks after AVM induction for 6 weeks. Brain samples were collected at the end of the treatments for morphology, mRNA, and protein analyses. The influence of Alk1 downregulation on PDGFB (platelet-derived growth factor B) expression was also studied on cultured human brain microvascular endothelial cells. The effect of PDGFB in mural cell recruitment in bAVM was explored by injection of a PDGFB overexpressing lentiviral vector to the mouse brain.

RESULTS

Thalidomide or lenalidomide treatment reduced the number of dysplastic vessels and hemorrhage and increased mural cell (vascular smooth muscle cells and pericytes) coverage in the bAVM lesion. Thalidomide reduced the burden of CD68⁺ cells and the expression of inflammatory cytokines in the bAVM lesions. PDGFB expression was reduced in ALK1-knockdown human brain microvascular endothelial cells and in mouse bAVM lesion. Thalidomide increased Pdgfb expression in bAVM lesion. Overexpression of PDGFB mimicked the effect of thalidomide.

CONCLUSIONS

Thalidomide and lenalidomide improve mural cell coverage of bAVM vessels and reduce bAVM hemorrhage, which is likely through upregulation of Pdgfb expression.

The small GTPase RhoU lays downstream of JAK/STAT signaling and mediates cell migration in multiple myeloma

Multiple myeloma is a post-germinal center B-cell neoplasm, characterized by the proliferation of malignant bone marrow plasma cells, whose survival and proliferation is sustained by growth factors and cytokines present in the bone marrow microenvironment. Among them, IL-6 triggers the signal downstream of its receptor, leading to the activation of the JAK/STAT pathway. The atypical GTPase RhoU lays downstream of STAT3 transcription factor and could be responsible for mediating its effects on cytoskeleton dynamics. Here we demonstrate that RHOU is heterogeneously expressed in primary multiple myeloma cells and significantly modulated with disease progression. At the mRNA level, RHOU expression in myeloma patients correlated with the expression of STAT3 and its targets MIR21 and SOCS3. Also, IL-6 stimulation of human myeloma cell lines up-regulated RHOU through STAT3 activation. On the other hand, RhoU silencing led to a decrease in cell migration with the accumulation of actin stress fibers, together with a decrease in cyclin D2 expression and in cell cycle progression. Furthermore, we found that even though lenalidomide positively regulated RhoU expression leading to higher cell migration rates, it actually led to cell cycle arrest probably through a p21 dependent mechanism. Lenalidomide treatment in combination with RhoU silencing determined a loss of cytoskeletal organization inhibiting cell migration, and a further increase in the percentage of cells in a resting phase. These results unravel a role for RhoU not only in regulating the migratory features of malignant plasma cells, but also in controlling cell cycle progression.

PD-1 /PD-L1 checkpoint in hematological malignancies

Programmed cell death protein 1 (PD-1), is a cell surface receptor with an important role in down-regulating the immune system and promoting self-tolerance by suppressing T cell inflammatory activity. PD-1/PDL1 axis represents a checkpoint to control immune responses and it is often used as a mechanism of immune escaping by cancers and infectious diseases. Many data demonstrate its important role in solid tumors and report emerging evidences in lymphoproliferative disorders. In this review, we summarized the available data on the role of PD-1/PD-L1 checkpoint in lymphoproliferative diseases and the therapeutics use of monoclonal blocking antibodies.

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.

Spontaneous onset and transplant models of the Vk*MYC mouse show immunological sequelae comparable to human multiple myeloma

Background

The Vk*MYC transgenic and transplant mouse models of multiple myeloma (MM) are well established as a research tool for anti-myeloma drug discovery. However, little is known of the immune response in these models. Understanding the immunological relevance of these models is of increasing importance as immunotherapeutic drugs are developed against MM.

Methods

We set out to examine how cellular immunity is affected in Vk*MYC mouse models and compare that to the immunology of patients with newly diagnosed and relapsed/refractory MM.

Results

We found that there were significant immunological responses in mice developing either spontaneous (transgenic) or transplanted MM as a consequence of the degree of tumor burden. Particularly striking were the profound B cell lymphopenia and the expansion of CD8⁺ effector memory T cells within the lymphocyte population that progressively developed with advancing disease burden, mirroring changes seen in human MM. High disease burden was also associated with increased inflammatory cytokine production by T lymphocytes, which is more fitting with relapsed/refractory MM in humans.

Conclusions

These findings have important implications for the application of this mouse model in the development of MM immunotherapies.

Trial registration LitVacc ANZCTR trial ID ACTRN12613000344796; RevLite ANZCTR trial ID NCT00482261

Stability of lenalidomide suspension after preparation by a simple suspension method for enteral tube administration

PURPOSE

A simple suspension method has been developed for tube administration, in which tablets (and capsules) are disintegrated in hot water (55℃) without grinding (or opening) them. In the present study, we evaluated the feasibility of this simple suspension method for the preparation of lenalidomide (Celgene, Summit, New Jersey and USA) suspension by testing the stability of this drug at 55℃ and its adsorbability on the tube.

METHODS

We examined, by high-performance liquid chromatography, the time-dependent changes in the concentration of lenalidomide in suspensions of the drug prepared by the simple suspension method. The high-performance liquid chromatography analyses of lenalidomide were performed on Prominence LC-20AB/SPD-20 A (Shimadzu, Kyoto, Japan) with a ZORBAX SB-C18 RR analytical column (Agilent Technologies, Santa Clara, California, USA; particle size: 2.1 × 100 mm, 3.5 µm) at a flow rate of 0.4 mL/min. A solvent system consisting of 10 mM ammonium acetate (pH 7.0)/acetonitrile was used as the eluent and the eluate was detected by UV at 254 nm.

RESULTS

Lenalidomide was confirmed to remain stable in hot water at 55℃ for 24 h in the prepared suspension by the simple suspension method, and more than 99% of the drug could be recovered from the suspension. In addition, 94.5-98.0% of the drug amount could pass through a percutaneous endoscopic gastrostomy tube. Lenalidomide was scarcely adsorbed on to the percutaneous endoscopic gastrostomy tube made of polyurethane or polyvinyl chloride.

CONCLUSION

Lenalidomide was found to be stable even in hot water and was not adsorbed on to the percutaneous endoscopic gastrostomy tube.

Brain arteriovenous malformation modeling, pathogenesis, and novel therapeutic targets

Patients harboring brain arteriovenous malformation (bAVM) are at life-threatening risk of rupture and intracranial hemorrhage (ICH). The pathogenesis of bAVM has not been completely understood. Current treatment options are invasive, and ≈ 20 % of patients are not offered interventional therapy because of excessive treatment risk. There are no specific medical therapies to treat bAVMs. The lack of validated animal models has been an obstacle for testing hypotheses of bAVM pathogenesis and testing new therapies. In this review, we summarize bAVM model development and bAVM pathogenesis and potential therapeutic targets that have been identified during model development.

Long-term disease control in patients with newly diagnosed multiple myeloma after suspension of lenalidomide therapy

There are no systematic data regarding nonmaintained induction for those patients with multiple myeloma (MM) who do not receive consolidative autologous stem cell transplantation. Of 173 patients with newly diagnosed MM treated with lenalidomide and dexamethasone (LenDex) as primary therapy, 31 patients had their lenalidomide discontinued for reasons other than progression or alternate therapy. Median progression free survival (PFS) from the time of discontinuing lenalidomide was longer in patients who received lenalidomide ≥ 1 year (39 vs. 13 months, P < 0.05); there was no difference in PFS for those treated for 1-2 years as compared to ≥ 2 years. Among those taking lenalidomide for ≥ 1 year PFS was superior in patients who were in very good partial response (VGPR) or better as compared to those with partial response (48.4 versus 14.8 months, P < 0.05). All patients who progressed and were rechallenged with LenDex responded. These analyses illustrate that discontinuation of lenalidomide after 1 year among those patients achieving a ≥VGPR can result in long-term disease control.

Lenalidomide

Lenalidomide is an immunomodulatory drug (IMiD), which is well established and approved in the treatment of multiple myeloma (MM) and 5q-myelodysplastic syndrome (MDS). The mode of action includes immune modulation, anti-angiogenetic, anti-inflammatory, and anti-proliferative effects. Development of lenalidomide initiated a profound shift in therapeutic approaches especially toward MM. This chapter will discuss the mode of action of lenalidomide as well as its clinical applications. Important clinical phase II and III data of lenalidomide are presented. Currently, lenalidomide is not only investigated in MM and MDS, but also in malignant lymphomas and other entities.

Second autologous transplant as salvage therapy in multiple myeloma

High-dose chemotherapy followed by autologous haematopoetic stem cell transplantation (ASCT) is a standard frontline therapy for multiple myeloma (MM). Unfortunately, there are no randomized clinical studies examining the role of a second ASCT in patients who relapse after the initial autotransplant. Analysing all available retrospective studies, it seems that salvage ASCT can safely be performed in most patients with an overall treatment-related mortality rate <5%. Approximately 65% of patients will achieve an objective response and progression-free and overall survival will be around 12 months and 32 months, respectively. Retrospective data suggest that patients with a progression-free survival of ≥18 months after initial ASCT are most likely to benefit from a salvage autotransplant. However, patients with a <12-month duration of response after initial ASCT should not be considered for a second autograft in the relapsed setting because this group will probably only experience ASCT-related toxicity without any clinical benefit. Quality of response after initial ASCT and number of therapies preceding salvage ASCT may also have a predictive value. Importantly, these findings need to be verified by randomized clinical trials in order to firmly integrate salvage ASCT into a global therapeutic concept for myeloma patients including optimized induction, consolidation, and maintenance approaches.

Evidence of a role for CD44 and cell adhesion in mediating resistance to lenalidomide in multiple myeloma: therapeutic implications

Resistance of myeloma to lenalidomide is an emerging clinical problem, and though it has been associated in part with activation of Wnt/β-catenin signaling, the mediators of this phenotype remained undefined. Lenalidomide-resistant models were found to overexpress the hyaluronan (HA)-binding protein CD44, a downstream Wnt/β-catenin transcriptional target. Consistent with a role of CD44 in cell adhesion-mediated drug resistance (CAM-DR), lenalidomide-resistant myeloma cells were more adhesive to bone marrow stroma and HA-coated plates. Blockade of CD44 with monoclonal antibodies, free HA or CD44 knockdown reduced adhesion and sensitized to lenalidomide. Wnt/β-catenin suppression by FH535 enhanced the activity of lenalidomide, as did interleukin-6 neutralization with siltuximab. Notably, all-trans retinoic acid (ATRA) downregulated total β-catenin, cell-surface and total CD44, reduced adhesion of lenalidomide-resistant myeloma cells and enhanced the activity of lenalidomide in a lenalidomide-resistant in vivo murine xenograft model. Finally, ATRA sensitized primary myeloma samples from patients that had relapsed and/or refractory disease after lenalidomide therapy to this immunomodulatory agent ex vivo. Taken together, our findings support the hypotheses that CD44 and CAM-DR contribute to lenalidomide resistance in multiple myeloma, that CD44 should be evaluated as a putative biomarker of sensitivity to lenalidomide, and that ATRA or other approaches that target CD44 may overcome clinical lenalidomide resistance.

Activation of coagulation by lenalidomide-based regimens for the treatment of multiple myeloma

We investigated the procoagulant effects of lenalidomide (Len)-based regimens in vitro focusing on tissue factor (TF) and phosphatidylserine (PS). We examined the effects of a pharmacological concentration of Len with or without the corticosteroid dexamethasone (Dex) and the proteasome inhibitor bortezomib (Bor) using the human vascular endothelial cell line EAhy926 and the monocytic cell lines THP-1 and U937. Cell-surface procoagulant activity (PCA) was induced by Dex-containing regimens in all lines. Expression of TF antigen on the cell surface and of TF mRNA was markedly increased by Dex-containing regimens. PS exposure was increased modestly by a Len-based regimen. PS exposure was increased modestly in EAhy926 cells, and markedly increased in THP-1 and U937 cells by Bor-containing treatment. An anti-TF monoclonal antibody almost completely blocked the induced PCA. When Len is given in combination with Dex, PCA may be induced on endothelial cells and monocytes through TF expression and PS exposure.