Immunomodulatory drug costimulates T cells via the B7-CD28 pathway

Iberdomide increases innate and adaptive immune cell subsets in the bone marrow of patients with relapsed/refractory multiple myeloma

Iberdomide is a potent cereblon E3 ligase modulator (CELMoD agent) with promising efficacy and safety as a monotherapy or in combination with other therapies in patients with relapsed/refractory multiple myeloma (RRMM). Using a custom mass cytometry panel designed for large-scale immunophenotyping of the bone marrow tumor microenvironment (TME), we demonstrate significant increases of effector T and natural killer (NK) cells in a cohort of 93 patients with multiple myeloma (MM) treated with iberdomide, correlating findings to disease characteristics, prior therapy, and a peripheral blood immune phenotype. Notably, changes are dose dependent, associated with objective response, and independent of prior refractoriness to MM therapies. This suggests that iberdomide broadly induces innate and adaptive immune activation in the TME, contributing to its antitumor efficacy. Our approach establishes a strategy to study treatment-induced changes in the TME of patients with MM and, more broadly, patients with cancer and establishes rational combination strategies for iberdomide with immune-enhancing therapies to treat MM.

Immunomodulatory drugs: a promising clinical ally for cancer immunotherapy

While immunomodulatory imide drugs (IMiDs) have been authorised for treatment of haematological cancers for over two decades, the appreciation of their ability to stimulate antitumour T cell and natural killer (NK) cell responses is relatively recent. Clinical trial data increasingly show that targeted immunotherapies, such as antibodies, T cells, and vaccines, improve outcomes when delivered in combination with the IMiD derivatives lenalidomide or pomalidomide. Here, we review these clinical data to highlight the relevance of IMiDs in combinatorial immunotherapy for both haematological and solid tumours. Further research into the molecular mechanisms of IMiDs and an increased understanding of their immunomodulatory effects may refine the specific applications of IMiDs and improve the design of future clinical trials, moving IMiDs to the forefront of combinatorial cancer immunotherapy.

Immune status and selection of patients for immunotherapy in myeloma: a proposal

ABSTRACT

Newer immune-based approaches based on recruitment and redirection of endogenous and/or synthetic immunity such as chimeric antigen receptor T cells or bispecific antibodies are transforming the clinical management of multiple myeloma (MM). Contributions of the immune system to the antitumor effects of myeloma therapies are also increasingly appreciated. Clinical malignancy in MM originates in the setting of systemic immune alterations that begin early in myelomagenesis and regional changes in immunity affected by spatial contexture. Preexisting and therapy-induced changes in immune cells correlate with outcomes in patients with MM including after immune therapies. Here, we discuss insights from and limitations of available data about immune status and outcomes after immune therapies in patients with MM. Preexisting variation in systemic and/or regional immunity is emerging as a major determinant of the efficacy of current immune therapies as well as vaccines. However, MM is a multifocal malignancy. As with solid tumors, integrating spatial aspects of the tumor and consideration of immune targets with the biology of immune cells may be critical to optimizing the application of immune therapy, including T-cell redirection, in MM. We propose 5 distinct spatial immune types of MM that may provide an initial framework for the optimal application of specific immune therapies in MM: immune depleted, immune permissive, immune excluded, immune suppressed, and immune resistant. Such considerations may also help optimize rational patient selection for emerging immune therapies to improve outcomes.

A single-cell atlas characterizes dysregulation of the bone marrow immune microenvironment associated with outcomes in multiple myeloma

Multiple Myeloma (MM) remains incurable despite advances in treatment options. Although tumor subtypes and specific DNA abnormalities are linked to worse prognosis, the impact of immune dysfunction on disease emergence and/or treatment sensitivity remains unclear. We established a harmonized consortium to generate an Immune Atlas of MM aimed at informing disease etiology, risk stratification, and potential therapeutic strategies. We generated a transcriptome profile of 1,149,344 single cells from the bone marrow of 263 newly diagnosed patients enrolled in the CoMMpass study and characterized immune and hematopoietic cell populations. Associating cell abundances and gene expression with disease progression revealed the presence of a proinflammatory immune senescence-associated secretory phenotype in rapidly progressing patients. Furthermore, signaling analyses suggested active intercellular communication involving APRIL-BCMA, potentially promoting tumor growth and survival. Finally, we demonstrate that integrating immune cell levels with genetic information can significantly improve patient stratification.

Cereblon-Targeting Ligase Degraders in Myeloma: Mechanisms of Action and Resistance

Cereblon-targeting degraders, including immunomodulatory imide drugs lenalidomide and pomalidomide alongside cereblon E3 ligase modulators like iberdomide and mezigdomide, have demonstrated significant anti-myeloma effects. These drugs play a crucial role in diverse therapeutic approaches for multiple myeloma (MM), emphasizing their therapeutic importance across various disease stages. Despite their evident efficacy, approximately 5% to 10% of MM patients exhibit primary resistance to lenalidomide, and resistance commonly develops over time. Understanding the intricate mechanisms of action and resistance to this drug class becomes imperative for refining and advancing novel therapeutic combinations.

Natural killer cells affect the natural course, drug resistance, and prognosis of multiple myeloma

Multiple myeloma (MM), a stage-developed plasma cell malignancy, evolves from monoclonal gammopathy of undetermined significance (MGUS) or smoldering MM (SMM). Emerging therapies including immunomodulatory drugs, proteasome inhibitors, monoclonal antibodies, chimeric antigen-T/natural killer (NK) cells, bispecific T-cell engagers, selective inhibitors of nuclear export, and small-molecule targeted therapy have considerably improved patient survival. However, MM remains incurable owing to inevitable drug resistance and post-relapse rapid progression. NK cells with germline-encoded receptors are involved in the natural evolution of MGUS/SMM to active MM. NK cells actively recognize aberrant plasma cells undergoing malignant transformation but are yet to proliferate during the elimination phase, a process that has not been revealed in the immune editing theory. They are potential effector cells that have been neglected in the therapeutic process. Herein, we characterized changes in NK cells regarding disease evolution and elucidated its role in the early clinical monitoring of MM. Additionally, we systematically explored dynamic changes in NK cells from treated patients who are in remission or relapse to explore future combination therapy strategies to overcome drug resistance.

Evolving CAR-T-Cell Therapy for Cancer Treatment: From Scientific Discovery to Cures

In recent years, chimeric antigen receptor (CAR)-T-cell therapy has emerged as the most promising immunotherapy for cancer that typically uses patients' T cells and genetically engineered them to target cancer cells. Although recent improvements in CAR-T-cell therapy have shown remarkable success for treating hematological malignancies, the heterogeneity in tumor antigens and the immunosuppressive nature of the tumor microenvironment (TME) limits its efficacy in solid tumors. Despite the enormous efforts that have been made to make CAR-T-cell therapy more effective and have minimal side effects for treating hematological malignancies, more research needs to be conducted regarding its use in the clinic for treating various other types of cancer. The main concern for CAR-T-cell therapy is severe toxicities due to the cytokine release syndrome, whereas the other challenges are associated with complexity and immune-suppressing TME, tumor antigen heterogeneity, the difficulty of cell trafficking, CAR-T-cell exhaustion, and reduced cytotoxicity in the tumor site. This review discussed the latest discoveries in CAR-T-cell therapy strategies and combination therapies, as well as their effectiveness in different cancers. It also encompasses ongoing clinical trials; current challenges regarding the therapeutic use of CAR-T-cell therapy, especially for solid tumors; and evolving treatment strategies to improve the therapeutic application of CAR-T-cell therapy.

Lenalidomide arrests cell cycle and modulates PD1-dependent downstream mTOR intracellular signals in melanoma cells

Despite numerous efforts to define the best therapeutic strategies in advanced melanoma, the response of many patients remains heterogeneous and of short duration. Lenalidomide, an immunomodulating drug, has shown anti-inflammatory, antiangiogenic and anticancer properties in haematological disorders; however, few preclinical data support the rationale for using this drug in melanoma patients. In this study, we investigate lenalidomide's potential role in melanoma by focusing on the in-vitro drug's antiproliferative activity. The antiproliferative action of lenalidomide was evaluated on two melanoma cell lines by MTT assay, cell cycle and apoptosis assay. P21 protein levels were evaluated with droplet digital PCR (ddPCR) and western blot analysis while his interaction with specific cyclin-dependent kinase (CDK) was assessed by immunoprecipitation test. The biological effect and molecular mechanisms of programmed cell death-1 (PD-1) in the regulation of proliferation were evaluated using ddPCR, flow cytometry, western blot and small interfering RNA transfection. We observed that lenalidomide exerts a cytostatic effect in melanoma cell lines by inducing cell cycle arrest in the G0-G1 phase through p21 upregulation and modulation of CDK complexes. Furthermore, we found that lenalidomide has an antiproliferative action through the downregulation of melanoma-PD1 expression and consequently the alteration of intracellular signaling of mammalian target of rapamycin/S6. The present study aims to provide new insights into the role of lenalidomide in melanoma and suggesting to potentially translating these findings into a clinical setting to use immunomodulatory derivatives for blocking the pro-tumorigenic activity of the melanoma through the PD-1/PD-L1 axis.

Short-term assays for mesenchymal stromal cell immunosuppression of T-lymphocytes

Introduction

Trauma patients are susceptible to coagulopathy and dysfunctional immune responses. Mesenchymal stromal cells (MSCs) are at the forefront of the cellular therapy revolution with profound immunomodulatory, regenerative, and therapeutic potential. Routine assays to assess immunomodulation activity examine MSC effects on proliferation of peripheral blood mononuclear cells (PBMCs) and take 3-7 days. Assays that could be done in a shorter period of time would be beneficial to allow more rapid comparison of different MSC donors. The studies presented here focused on assays for MSC suppression of mitogen-stimulated PBMC activation in time frames of 24 h or less.

Methods

Three potential assays were examined-assays of apoptosis focusing on caspase activation, assays of phosphatidyl serine externalization (PS+) on PBMCs, and measurement of tumor necrosis factor alpha (TNFα) levels using rapid ELISA methods. All assays used the same initial experimental conditions: cryopreserved PBMCs from 8 to 10 pooled donors, co-culture with and without MSCs in 96-well plates, and PBMC stimulation with mitogen for 2-72 h.

Results

Suppression of caspase activity in activated PBMCs by incubation with MSCs was not robust and was only significant at times after 24 h. Monitoring PS+ of live CD3+ or live CD4+/CD3+ mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, 2 h, although no increase in the percentage of PS+ cells was seen with time. The ability of MSC in co-culture to suppress PBMC PS+ externalization compared favorably to two concomitant assays for MSC co-culture suppression of PBMC proliferation, at 72 h by ATP assay, or at 96 h by fluorescently labeled protein signal dilution. TNFα release by mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, with accumulating signal over time. However, suppression levels with MSC co-culture was reliably seen only after 24 h.

Discussion

Takeaways from these studies are as follows: (1) while early measures of PBMC activation is evident at 2-6 h, immunosuppression was only reliably detected at 24 h; (2) PS externalization at 24 h is a surrogate assay for MSC immunomodulation; and (3) rapid ELISA assay detection of TNFα release by PBMCs is a robust and sensitive assay for MSC immunomodulation at 24 h.

Phase II Randomized Trial of Lenalidomide in Children With Pilocytic Astrocytomas and Optic Pathway Gliomas: A Report From the Children's Oncology Group

PURPOSE

Children with low-grade glioma often require long-term therapy and suffer from treatment morbidity. Although targeted agents are promising, tumor targets often encompass normal developmental pathways and long-term effects of inhibition are unknown. Lenalidomide is an immunomodulatory agent with wide-ranging properties. Phase I studies indicated greater tolerability of lenalidomide in children compared with adults and a potential dose-response effect.

PATIENTS AND METHODS

We performed a phase II trial of lenalidomide in children with pilocytic astrocytomas and optic pathway gliomas who failed initial therapy. Primary objectives included determination of objective response rate of children randomly assigned to regimen A, low-dose (20 mg/m2/dose), or regimen B, high-dose (115 mg/m2/dose) lenalidomide, and assessment for early progression. Secondary objectives included estimation of event-free survival, overall survival, incidence of toxic events, and assessment of plasma lenalidomide concentrations. Lenalidomide was administered once daily × 21 days of each 28-day cycle for each regimen.

RESULTS

Seventy-four eligible patients were enrolled (n = 37, each arm). The predefined activity level of interest was achieved for both arms. Four objective responses were observed in each arm, and the number of early progressors was low. Eighteen patients completed 26 cycles of therapy (regimen A, n = 12; regimen B, n = 6). The median number of cycles was 14 (range, 2-26) for regimen A and 11 for regimen B (range, 1-26). Of 74 eligible patients who received study drug, 30 required dose reduction for toxicity (regimen A, n = 6; regimen B, n = 24) and 16 discontinued because of toxicity (regimen A, n = 2; regimen B, n = 14).

CONCLUSION

Lenalidomide demonstrates a sufficient level of activity in children with low-grade glioma to warrant further exploration. Low-dose (20 mg/m2/dose administered once daily × 21 days of each 28-day cycle) lenalidomide appears to have better tolerability with comparable activity.

Determining Optimal Combination Regimens for Patients with Multiple Myeloma

While many novel therapies have been approved in recent years for treating patients with multiple myeloma, there is still no established curative regimen, especially for patients with high-risk disease. In this work, we use a mathematical modeling approach to determine combination therapy regimens that maximize healthy lifespan for patients with multiple myeloma. We start with a mathematical model for the underlying disease and immune dynamics, which was presented and analyzed previously. We add the effects of three therapies to the model: pomalidomide, dexamethasone, and elotuzumab. We consider multiple approaches to optimizing combinations of these therapies. We find that optimal control combined with approximation outperforms other methods, in that it can quickly produce a combination regimen that is clinically-feasible and near-optimal. Implications of this work can be used to optimize doses and advance the scheduling of drugs.

Lenalidomide overcomes the resistance to third-generation CD19-CAR-T cell therapy in preclinical models of diffuse large B-cell lymphoma

PURPOSE

Chimeric antigen receptor (CAR)-T cells against CD19 have been proven to be effective in treating B-cell hematological malignancies. However, the efficacy of this promising therapy is limited by many factors.

METHODS

In this study, the germinal center B-cell-like diffuse large B-cell lymphoma (GCB-DLBCL) cell line OCI-Ly1, and patient-derived xenografted (PDX) mice (CY-DLBCL) were used as the CAR-T cell-resistant model. Meanwhile, the activated B-cell-like (ABC) DLBCL cell line OCI-Ly3 and PDX mice (ZML-DLBCL) were defined as the CAR-T sensitive model. The enhancement of CAR-T cell function by lenalidomide (LEN) was examined in vitro and in vivo.

RESULTS

Lenalidomide effectively enhanced the function of third-generation CD19-CAR-T cells by polarizing CD8⁺ CAR-T cells to CD8 early-differentiated stage and Th1 type, reducing CAR-T cell exhaustion and improving cell expansion. It was further demonstrated that CAR-T cells combined with LEN substantially reduce the tumor burden and prolong the survival time in various DLBCL mouse models. LEN was also found to promote the infiltration of CD19-CAR-T cells into the tumor site by modulating the tumor microenvironment.

CONCLUSION

In summary, the results of the present study suggest that LEN can improve the function of CD19-CAR-T cells, providing a basis for clinical trials using this combination therapy against DLBCL.

Exosome-Modified Liposomes Targeted Delivery of Thalidomide to Regulate Treg Cells for Antitumor Immunotherapy

Thalidomide (THD), a synthetic derivative of glutamic acid, was initially used as a sedative and antiemetic until the 1960s, when it was found to cause devastating teratogenic effects. However, subsequent studies have clearly demonstrated the anti-inflammatory, anti-angiogenic, and immunomodulatory properties of thalidomide, thus providing a rationale for its current use in the treatment of various autoimmune diseases and cancers. Our group found that thalidomide can suppress the regulatory T cells (Tregs), a minor subset of CD4+ T cells (~10%) with unique immunosuppressive activity that have been shown to accumulate in the tumor microenvironment (TME) and represent a major mechanism of tumor immune evasion. Due to the low solubility of thalidomide in its present form of administration, coupled with its lack of specificity for targeted delivery and controlled drug release, it is an urgent need to find potent delivery methods that can significantly enhance its solubility, optimize the desired site of drug action, and mitigate its toxicity. In this study, the isolated exosomes were incubated with synthetic liposomes to form hybrid exosomes (HEs) that carried THD (HE-THD) with uniform size distribution. The results demonstrated that HE-THD could significantly abrogate the expansion and proliferation of Tregs induced by TNF, and this might result from blocking TNF-TNFR2 interaction. By encapsulating THD in hybrid exosomes, our drug delivery system successfully increased the solubility of THD, laying a foundation for future in vivo experiments that validate the antitumor activity of HE-THD by reducing the Treg frequency within the tumor microenvironment.

CAR-T cell combination therapy: the next revolution in cancer treatment

In recent decades, the advent of immune-based therapies, most notably Chimeric antigen receptor (CAR)-T cell therapy has revolutionized cancer treatment. The promising results of numerous studies indicate that CAR-T cell therapy has had a remarkable ability and successful performance in treating blood cancers. However, the heterogeneity and immunosuppressive tumor microenvironment (TME) of solid tumors have challenged the effectiveness of these anti-tumor fighters by creating various barriers. Despite the promising results of this therapeutic approach, including tumor degradation and patient improvement, there are some concerns about the efficacy and safety of the widespread use of this treatment in the clinic. Complex and suppressing tumor microenvironment, tumor antigen heterogeneity, the difficulty of cell trafficking, CAR-T cell exhaustion, and reduced cytotoxicity in the tumor site limit the applicability of CAR-T cell therapy and highlights the requiring to improve the performance of this treatment. With this in mind, in the last decade, many efforts have been made to use other treatments for cancer in combination with tuberculosis to increase the effectiveness of CAR-T cell therapy, especially in solid tumors. The combination therapy results have promising consequences for tumor regression and better cancer control compared to single therapies. Therefore, this study aimed to comprehensively discuss different cancer treatment methods in combination with CAR-T cell therapy and their therapeutic outcomes, which can be a helpful perspective for improving cancer treatment in the near future.

Advances in the molecular characterization of multiple myeloma and mechanism of therapeutic resistance

Recent insight in the genomic landscape of newly diagnosed multiple myeloma (NDMM) and its precursor conditions, monoclonal gammopathy of uncertain significance (MGUS), and smoldering myeloma have allowed the identification of patients with precursor conditions with a high risk of progression. These cases with "progressor" MGUS/SMM have a higher average mutation burden, have higher rates of mutations in specific genes such as MAPK, DNA repair, MYC, DIS3, and are enriched for specific mutational signatures when compared to non-progressors and are comparable to those found in NDMM. The highly preserved clonal heterogeneity seen upon progression of SMM, combined with the importance of these early variables, suggests that the identification of progressors based on these findings could complement and enhance the currently available clinical models based on tumor burden. Mechanisms leading to relapse/refractory multiple myeloma (RRMM) are of clinical interest given worse overall survival in this population. An Increased mutational burden is seen in patients with RRMM when compared to NDMM, however, there is evidence of branching evolution with many of these mutations being present at the subclonal level. Likewise, alterations in proteins associated with proteosome inhibitor and immunomodulatory drugs activity could partially explain clinical resistance to these agents. Evidence of chromosomal events leading to copy number changes is seen, with the presence of TP53 deletion, mutation, or a combination of both being present in many cases. Additional chromosomal events such as 1q gain and amplification may also interact and lead to resistance.

Reshaping the tumor microenvironment: The versatility of immunomodulatory drugs in B-cell neoplasms

Immunomodulatory drugs (IMiDs) such as thalidomide, lenalidomide and pomalidomide are antitumor compounds that have direct tumoricidal activity and indirect effects mediated by multiple types of immune cells in the tumor microenvironment (TME). IMiDs have shown remarkable therapeutic efficacy in a set of B-cell neoplasms including multiple myeloma, B-cell lymphomas and chronic lymphocytic leukemia. More recently, the advent of immunotherapy has revolutionized the treatment of these B-cell neoplasms. However, the success of immunotherapy is restrained by immunosuppressive signals and dysfunctional immune cells in the TME. Due to the pleiotropic immunobiological properties, IMiDs have shown to generate synergetic effects in preclinical models when combined with monoclonal antibodies, immune checkpoint inhibitors or CAR-T cell therapy, some of which were successfully translated to the clinic and lead to improved responses for both first-line and relapsed/refractory settings. Mechanistically, despite cereblon (CRBN), an E3 ubiquitin ligase, is considered as considered as the major molecular target responsible for the antineoplastic activities of IMiDs, the exact mechanisms of action for IMiDs-based TME re-education remain largely unknown. This review presents an overview of IMiDs in regulation of immune cell function and their utilization in potentiating efficacy of immunotherapies across multiple types of B-cell neoplasms.

Clinical Strategies for Enhancing the Efficacy of CAR T-Cell Therapy for Hematological Malignancies

Chimeric antigen receptor (CAR) T cells have been successfully used for hematological malignancies, especially for relapsed/refractory B-cell acute lymphoblastic leukemia and non-Hodgkin’s lymphoma. Patients who have undergone conventional chemo-immunotherapy and have relapsed can achieve complete remission for several months with the infusion of CAR T-cells. However, side effects and short duration of response are still major barriers to further CAR T-cell therapy. To improve the efficacy, multiple targets, the discovery of new target antigens, and CAR T-cell optimization have been extensively studied. Nevertheless, the fact that the determination of the efficacy of CAR T-cell therapy is inseparable from the discussion of clinical application strategies has rarely been discussed. In this review, we will discuss some clinical application strategies, including lymphodepletion regimens, dosing strategies, combination treatment, and side effect management, which are closely related to augmenting and maximizing the efficacy of CAR T-cell therapy.

Early administration of lenalidomide after allogeneic hematopoietic stem cell transplantation suppresses graft-versus-host disease by inhibiting T-cell migration to the gastrointestinal tract

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (aHSCT) is a curative treatment for hematopoietic malignancies. Graft-versus-host disease (GVHD) is a major complication of aHSCT. After transplantation, the balance of immune conditions, such as proinflammatory cytokine level and T-cell subset count, influences GVHD magnitude. Lenalidomide (LEN) is an immunomodulatory drug used for treating several hematological malignancies such as multiple myeloma, adult T-cell lymphoma/leukemia, and follicular lymphoma. However, the impact of LEN on immune responses after aHSCT has not been elucidated.

METHODS

We analyzed the lymphocyte composition in naïve mice treated with LEN. Subsequently, we treated host mice with LEN, soon after aHSCT, and analyzed GVHD severity as well as the composition and characteristics of lymphocytes associated with GVHD.

RESULTS

Using a mouse model, we demonstrated the beneficial effects of LEN for treating acute GVHD. Although natural killer cells were slightly increased by LEN, it did not significantly change T-cell proliferation and the balance of the T-cell subset in naïve mice. LEN did not modulate the suppressive function of regulatory T cells (Tregs). Unexpectedly, LEN prevented severe GVHD in a mouse acute GVHD model. Donor-derived lymphocytes were more numerous in host mice treated with LEN than in host mice treated with vehicle. Lymphocyte infiltration of the gastrointestinal tract in host mice treated with LEN was less severe compared to that in host mice treated with vehicle. The percentage of LPAM-1 (α4 β7 -integrin)-expressing Foxp3- CD4+ T cells was significantly lower in host mice treated with LEN than in host mice treated with vehicle, whereas that of LPAM-1-expressing Tregs was comparable.

CONCLUSIONS

LEN may be useful as a prophylactic agent for acute GVHD-induced mortality through the inhibition of lymphocyte migration to the gastrointestinal tract. Our data show the effect of LEN on immune responses early after aHSCT and suggest that cereblon, a molecular target of LEN, may be a therapeutic target for preventing acute GVHD-induced mortality.

Current options and future perspectives in the treatment of patients with relapsed/refractory diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) represents the most common subtype of aggressive lymphoma. Depending on individual risk factors, roughly 60–65% of patients can be cured by chemoimmunotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). However, patients with primary refractory disease or relapse (R/R) after an initial response are still characterized by poor outcome. Until now, transplant-eligible R/R DLBCL patients are treated with intensive salvage regimens followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT) which, however, only cures a limited number of patients. It is most likely that in patients with early relapse after chemoimmunotherapy, chimeric antigen receptor (CAR) T-cells will replace high-dose chemotherapy and ASCT. So far, transplant-ineligible patients have mostly been treated in palliative intent. Recently, a plethora of novel agents comprising new monoclonal antibodies, antibody drug conjugates (ADC), bispecific antibodies, and CAR T-cells have emerged and have significantly improved outcome of patients with R/R DLBCL. In this review, we summarize our current knowledge on the usage of novel drugs and approaches for the treatment of patients with R/R DLBCL.

What's Old is New: The Past, Present and Future Role of Thalidomide in the Modern-Day Management of Multiple Myeloma

Immunomodulatory drugs (IMiDs) have become an integral part of therapy for both newly diagnosed and relapsed/refractory multiple myeloma (RRMM). IMiDs bind to cereblon, leading to the degradation of proteins involved in B-cell survival and proliferation. Thalidomide, a first-generation IMiD, has little to no myelosuppressive potential, negligible renal clearance, and long-proven anti-myeloma activity. However, thalidomide's adverse effects (e.g., somnolence, constipation, and peripheral neuropathy) and the advent of more potent therapeutic options has led to the drug being less frequently used in many countries, including the US and Canada. Newer-generation IMiDs, such as lenalidomide and pomalidomide, are utilized far more frequently. In numerous previous trials, salvage therapy with thalidomide (50-200 mg/day) plus corticosteroids (with or without selected cytotoxic or targeted agents) has been shown to be effective and well-tolerated in the RRMM setting. Hence, thalidomide-based regimens remain important alternatives for heavily pretreated patients, especially for those who have no access to novel therapies and/or are not eligible for their use (due to renal failure, high-grade myelosuppression, or significant comorbidities). Ongoing and future trials may provide further insights into the current role of thalidomide, especially by comparing thalidomide-containing regimens with protocols based on newer-generation IMiDs and by investigating thalidomide's association with novel therapies (e.g., antibody-drug conjugates, bispecific antibodies, and chimeric antigen receptor T cells).

Lenalidomide bypasses CD28 co-stimulation to reinstate PD-1 immunotherapy by activating Notch signaling

Programmed cell death protein 1 (PD-1) checkpoint blockade therapy requires the CD28 co-stimulatory receptor for CD8⁺ T cell expansion and cytotoxicity. However, CD28 expression is frequently lost in exhausted T cells and during immune senescence, limiting the clinical benefits of PD-1 immunotherapy in individuals with cancer. Here, using a cereblon knockin mouse model that regains in vivo T cell response to lenalidomide, an immunomodulatory imide drug, we show that lenalidomide reinstates the anti-tumor activity of CD28-deficient CD8⁺ T cells after PD-1 blockade. Lenalidomide redirects the CRL4^Crbn ubiquitin ligase to degrade Ikzf1 and Ikzf3 in T cells and unleashes paracrine interleukin-2 (IL-2) and intracellular Notch signaling, which collectively bypass the CD28 requirement for activation of intratumoral CD8⁺ T cells and inhibition of tumor growth by PD-1 blockade. Our results suggest that PD-1 immunotherapy can benefit from a lenalidomide combination when treating solid tumors infiltrated with abundant CD28^- T cells.

Resistance against anti-CD19 and anti-BCMA CAR T cells: Recent advances and coping strategies

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Some patients may experience resistance to CD19 CAR T cell and BCMA CAR T cell therapies or relapse after treatment.

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Mechanisms of resistance to CAR T cell therapies may be related to CAR structure, T cell factors or tumor associated factors.

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The strategies to overcome the resistance would allow CD19 CAR T cells or BCMA CAR T cell to be applied with a broader perspective.

Chimeric antigen receptor T (CAR T) cell therapy is a new treatment paradigm that has revolutionized the treatment of CD19-positive B cell malignancies and BCMA-positive plasma cell malignancies. The response rates are highly impressive in comparison to historical cohorts, but the responses are not durable. The most recent results from pivotal trials show that current CAR T cell products fail to demonstrate optimal long-term disease control. Resistance to CAR T cells is related to CAR structure, T cell factors, tumor factors and the immunosuppressive microenvironment. Novel strategies are needed following failure with CAR T cell treatment. In this review, we discuss the resistance mechanisms to CAR T cell treatment according to disease and the emerging strategies to overcome resistance.

Preparing for CAR T cell therapy: patient selection, bridging therapies and lymphodepletion

Chimeric antigen receptor (CAR) T cells have emerged as a potent therapeutic approach for patients with certain haematological cancers, with multiple CAR T cell products currently approved by the FDA for those with relapsed and/or refractory B cell malignancies. However, in order to derive the desired level of effectiveness, patients need to successfully receive the CAR T cell infusion in a timely fashion. This process entails apheresis of the patient's T cells, followed by CAR T cell manufacture. While awaiting infusion at an authorized treatment centre, patients may receive interim disease-directed therapy. Most patients will also receive a course of pre-CAR T cell lymphodepletion, which has emerged as an important factor in enabling durable responses. The time between apheresis and CAR T cell infusion is often not a simple journey, with each milestone being a critical step that can have important downstream consequences for the ability to receive the infusion and the strength of clinical responses. In this Review, we provide a summary of the many considerations for preparing patients with B cell non-Hodgkin lymphoma or acute lymphoblastic leukaemia for CAR T cell therapy, and outline current limitations and areas for future research.

Transplant Onconephrology in Patients With Kidney Transplants

Cancer is a leading cause of death in patients with kidney transplantation. Patients with kidney transplants are 10- to 200-times more likely to develop cancers after transplant than the general population, depending on the cancer type. Recent advances in cancer therapies have dramatically improved survival outcomes; however, patients with kidney transplants face unique challenges of immunosuppression management, cancer screening, and recurrence of cancer after transplant. Patients with a history of cancer tend to be excluded from transplant candidacy or are required to have long cancer-free wait time before wait-listing. The strategy of pretransplant wait time management may need to be revisited as cancer therapies improve, which is most applicable to patients with a history of multiple myeloma. In this review, we discuss several important topics in transplant onconephrology: the current recommendations for pretransplant wait times for transplant candidates with cancer histories, cancer screening post-transplant, post-transplant lymphoproliferative disorder, strategies for transplant patients with a history of multiple myeloma, and novel therapies for patients with post-transplant malignancies. With emerging novel cancer treatments, it is critical to have multidisciplinary discussions involving patients, caregivers, transplant nephrologists, and oncologists to achieve patient-oriented goals.

Promising Antigens for the New Frontier of Targeted Immunotherapy in Multiple Myeloma

Simple Summary

Defining the specificity and biological sequalae induced by receptors differentiated expressed in multiple myeloma cells are critical for the development of effective immunotherapies based on monoclonal antibodies. Ongoing studies continue to discover new antigens with superior tumor selectivity and defined function in regulating the pathophysiology of myeloma cells directly or indirectly in the immunosuppressive bone marrow microenvironment. Meanwhile, it is urgent to identify mechanisms of immune resistance and design more potent immunotherapies, alone and/or with best combination partners to further prolong anti-MM immunity.

Abstract

The incorporation of novel agents in recent treatments in multiple myeloma (MM) has improved the clinical outcome of patients. Specifically, the approval of monoclonal antibody (MoAb) against CD38 (daratumumab) and SLAMF7 (elotuzumab) in relapsed and refractory MM (RRMM) represents an important milestone in the development of targeted immunotherapy in MM. These MoAb-based agents significantly induce cytotoxicity of MM cells via multiple effector-dependent mechanisms and can further induce immunomodulation to repair a dysfunctional tumor immune microenvironment. Recently, targeting B cell maturation antigen (BCMA), an even MM-specific antigen, has shown high therapeutic activities by chimeric antigen receptor T cells (CAR T), antibody-drug conjugate (ADC), bispecific T-cell engager (BiTE), as well as bispecific antibody (BiAb), with some already approved for heavily pretreated RRMM patients. New antigens, such as orphan G protein-coupled receptor class C group 5 member D (GPRC5D) and FcRH5, were identified and rapidly moved to ongoing clinical studies. We here summarized the pathobiological function of key MM antigens and the status of the corresponding immunotherapies. The potential challenges and emerging treatment strategies are also discussed.

Preceding bortezomib administration for a certain period reduces the risk of lenalidomide-induced skin rash

WHAT IS KNOWN AND OBJECTIVE

It was previously reported that the incidence of lenalidomide (LEN)-induced skin rash is reduced by administration of bortezomib (BOR) prior to LEN administration in patients with multiple myeloma (MM). Therefore, we investigated whether LEN-induced skin rash is affected by the duration of BOR administration and the dosing interval between BOR and LEN administration.

METHOD

A retrospective investigation was conducted among MM patients who received BOR treatment prior to LEN treatment in Eiju General Hospital from May 2010 to December 2020. We investigated whether the BOR administration duration and interval duration from the completion of BOR administration to the initial LEN administration affect the development of LEN-induced skin rash.

RESULT AND DISCUSSION

Twenty-eight of the 81 patients exhibited LEN-induced skin rash (34.6%). The administered duration, but not the interval, was significantly longer in the group without skin rash. Cut-off values were set for the duration of administration and interval, which were 35 days and 30 days, respectively. Multivariate analysis was performed on patients which are administered duration of more than 35 days and intervals of less than 30 days, and those who are not applicable. A significant difference was observed in the incidence of skin rash for each factor.

WHAT IS NEW AND CONCLUSION

The risk of reduced LEN-induced skin rash is affected not only by the presence of prior BOR administration, but also by the duration of BOR and the interval from the completion of BOR to the initial LEN administration.

Novel Molecular Mechanism of Lenalidomide in Myeloid Malignancies Independent of Deletion of Chromosome 5q

Lenalidomide as well as other immunomodulatory drugs (IMiDs) have achieved clinical efficacies in certain sub-types of hematologic malignancies, such as multiple myeloma, lower-risk myelodysplastic syndromes (MDS) with a single deletion of chromosome 5q (del(5q)) and others. Despite superior clinical response to lenalidomide in hematologic malignancies, relapse and resistance remains a problem in IMiD-based therapy. The last ten years have witnessed the discovery of novel molecular mechanism of IMiD-based anti-tumor therapy. IMiDs bind human cereblon (CRBN), the substrate receptor of the CRL4 E3 ubiquitin ligase complex. Binding of CRBN with IMiDs leads to degradation of the Ikaros family zinc finger proteins 1 and 3 (IKZF1 and IKZF3) and casein kinase 1 alpha. We have found that lenalidomide-mediated degradation of IKZF1 leads to activation of the G protein-coupled receptor 68 (GPR68)/calcium/calpain pro-apoptotic pathway and inhibition of the regulator of calcineurin 1 (RCAN1)/calcineurin pro-survival pathway in MDS and acute myeloid leukemia (AML). Calcineurin inhibitor Cyclosporin-A potentiates the anti-leukemia activity of lenalidomide in MDS/AML with or without del(5q). These findings broaden the therapeutic potential of IMiDs. This review summarizes novel molecular mechanism of lenalidomide in myeloid malignancies, especially without del(5q), in the hope to highlight novel therapeutic targets.

Immunotherapy in hematological malignancies: recent advances and open questions

Over recent years, tremendous advances in immunotherapy approaches have been observed, generating significant clinical progress. Cancer immunotherapy has been shown, in different types of blood cancers, to improve the overall survival of patients. Immunotherapy treatment of hematopoietic malignancies is a newly growing field that has been accelerating over the past years. Several US FDA approved drugs and cell-based therapies are being exploited in the late stage of clinical trials. This review attempt to highlight and discuss the numerous innovative immunotherapy approaches of hematopoietic malignancy ranging from nonmyeloablative transplantation, T-cell immunotherapy, natural killer cells and immune agonist to monoclonal antibodies and vaccination. In addition, a brief discussion on the future advances and accomplishments required to counterpart the current immunotherapeutic approaches for hematopoietic malignancies were also highlighted.

Immunomodulation by durvalumab and pomalidomide in patients with relapsed/refractory multiple myeloma

This study sought to understand how the programmed death ligand 1 (PD-L1) inhibitor durvalumab and the immunomodulatory agent pomalidomide regulate immune cell activation and function in patients with relapsed/refractory (RR) multiple myeloma (MM). Immunologic changes in peripheral blood and bone marrow of patients treated with durvalumab as monotherapy or in combination with pomalidomide with/without dexamethasone were characterized by assessing subsets of immune cells and gene signatures to understand the immunomodulatory effect of the treatment. Soluble PD-L1 levels were elevated at screening in patients with RRMM but did not correlate with response to durvalumab combination therapy. Immune cell subsets were increased in peripheral blood during treatment with durvalumab and pomalidomide, and combination therapy induced significant gene expression changes in the MM tumor microenvironment versus durvalumab alone. Estimation of cell populations based on RNA sequencing data revealed increased monocytes, neutrophils, and natural killer cells with the combination therapy, but not with durvalumab alone. Additionally, multiplex immunofluorescence of bone marrow demonstrated that immune populations were different in responders versus nonresponders to durvalumab plus pomalidomide with dexamethasone therapy. Overall, durvalumab effectively blocked soluble PD-L1; however, durvalumab monotherapy was not associated with immunologic changes, which were observed with combination therapy.

Developing next generation immunomodulatory drugs and their combinations in multiple myeloma

Multiple Myeloma (MM) is an incurable malignancy with current treatment choices primarily comprising combination regimens implemented with a risk-adapted approach. Cereblon (CRBN)-targeting immunomodulatory agents (IMiDs^®) lenalidomide (LEN) and pomalidomide (POM) play a central role in combination regimens due to their pleiotropic antitumor/immunomodulatory mechanisms that synergize with many anti-myeloma approved or developmental agents. Currently, more potent next generation cereblon E3 ligase modulators (CELMoDs^®) - iberdomide (IBER) and CC-92480 are in clinical development. With an expanding number of active agents/therapeutic modalities and a myriad of combinatorial possibilities, physicians and drug developers share an opportunity and challenge to combine and sequence therapies to maximize long-term patient benefit. Understanding drug mechanisms and their application in combination settings as well as the unique disease biology considerations from newly diagnosed (NDMM), relapsed/refractory (RRMM), and maintenance settings will be vital to guide the development of future MM therapies centered on a backbone of IMiD or CELMoD agents. Key aspects of drug activity are critical to consider while evaluating potential combinations: direct antitumor effects, indirect antitumor cytotoxicity, immune surveillance, and adverse side effects. In addition, the treatment journey from NDMM to early and late MM relapses are connected to genomic and immune changes associated with disease progression and acquisition of resistance mechanisms. Based on the types of combinations used and the goals of therapy, insights into mechanisms of drug activity and resistance may inform treatment decisions for patients with MM. Here we focus on the evolving understanding of the molecular mechanisms of CRBN-binding drugs and how they can be differentiated and suggest a strategic framework to optimize efficacy and safety of combinations using these agents.

ERK signaling mediates resistance to immunomodulatory drugs in the bone marrow microenvironment

Immunomodulatory drugs (IMiDs) have markedly improved patient outcome in multiple myeloma (MM); however, resistance to IMiDs commonly underlies relapse of disease. Here, we identify that tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) knockdown (KD)/knockout (KO) in MM cells mediates IMiD resistance via activation of noncanonical nuclear factor κB (NF-κB) and extracellular signal-regulated kinase (ERK) signaling. Within MM bone marrow (BM) stromal cell supernatants, TNF-α induces proteasomal degradation of TRAF2, noncanonical NF-κB, and downstream ERK signaling in MM cells, whereas interleukin-6 directly triggers ERK activation. RNA sequencing of MM patient samples shows nearly universal ERK pathway activation at relapse on lenalidomide maintenance therapy, confirming its clinical relevance. Combination MEK inhibitor treatment restores IMiD sensitivity of TRAF2 KO cells both in vitro and in vivo. Our studies provide the framework for clinical trials of MEK inhibitors to overcome IMiD resistance in the BM microenvironment and improve patient outcome in MM.

The immunomodulatory drugs lenalidomide and pomalidomide enhance the potency of AMG 701 in multiple myeloma preclinical models

We investigated here the novel immunomodulation and anti-multiple myeloma (MM) function of T cells engaged by the bispecific T-cell engager molecule AMG 701, and further examined the impact of AMG 701 in combination with immunomodulatory drugs (IMiDs; lenalidomide and pomalidomide). AMG 701 potently induced T-cell-dependent cellular cytotoxicity (TDCC) against MM cells expressing B-cell maturation antigen, including autologous cells from patients with relapsed and refractory MM (RRMM) (half maximal effective concentration, <46.6 pM). Besides inducing T-cell proliferation and cytolytic activity, AMG 701 also promoted differentiation of patient T cells to central memory, effector memory, and stem cell-like memory (scm) phenotypes, more so in CD8 vs CD4 T subsets, resulting in increased CD8/CD4 ratios in 7-day ex vivo cocultures. IMiDs and AMG 701 synergistically induced TDCC against MM cell lines and autologous RRMM patient cells, even in the presence of immunosuppressive bone marrow stromal cells or osteoclasts. IMiDs further upregulated AMG 701-induced patient T-cell differentiation toward memory phenotypes, associated with increased CD8/CD4 ratios, increased Tscm, and decreased interleukin 10-positive T and T regulatory cells (CD25highFOXP3high), which may downregulate T effector cells. Importantly, the combination of AMG 701 with lenalidomide induced sustained inhibition of MM cell growth in SCID mice reconstituted with human T cells; tumor regrowth was eventually observed in cohorts treated with either agent alone (P < .001). These results strongly support AMG 701 clinical studies as monotherapy in patients with RRMM (NCT03287908) and the combination with IMiDs to improve patient outcomes in MM.

Simple desensitization protocol for multiple myeloma patients with lenalidomide-induced skin rash: Case series

WHAT IS KNOWN AND OBJECTIVE

Skin rash is one of the typical side effects of lenalidomide (LEN) treatment. Desensitization therapies have been reported to be effective in patients with severe skin rash caused by LEN. However, they have proved impractical due to the complexity of the protocols.

CASE SUMMARIES

We present 5 patients who developed severe LEN-induced skin rash. The five patients received our simple, slow desensitization protocol, and all were re-administered LEN with no adverse reaction.

WHAT IS NEW AND CONCLUSION

Our simpler and slow desensitization protocol, which desensitizes the patients without reducing the effect of LEN, includes drug holidays, similar to the usual LEN dosing schedule, and moreover is recommended as a treatment option especially for elderly patients with no housemate to help with medical management.

Understanding the Role of T-Cells in the Antimyeloma Effect of Immunomodulatory Drugs

Immunomodulatory drugs (IMiDs) are effective treatments for patients with multiple myeloma. IMiDs have pleotropic effects including targeting the myeloma cells directly, and improving the anti-myeloma immune response. In the absence of myeloma cells, lenalidomide and pomalidomide induce CD4⁺ T cell secretion of IL-2 and indirect activation of Natural Killer (NK) cells. In the context of T cell receptor ligation, IMiDs enhance T cell proliferation, cytokine release and Th1 responses, both in vivo and in vitro. Furthermore, combination treatment of IMiDs and myeloma-targeting monoclonal antibodies eg. daratumumab (anti-CD38) and elotuzumab (anti-SLAMF7), checkpoint inhibitors, or bispecific T cell engagers showed synergistic effects, mainly via enhanced T and NK cell dependent cellular toxicity and T cell proliferation. Conversely, the corticosteroid dexamethasone can impair the immune modulatory effects of IMiDs, indicating that careful choice of myeloma drugs in combination with IMiDs is key for the best anti-myeloma therapeutic efficacy. This review presents an overview of the role for T cells in the overall anti-myeloma effects of immunomodulatory drugs.

Bystander Memory T Cells and IMiD/Checkpoint Therapy in Multiple Myeloma: A Dangerous Tango?

In this review article we discuss the role of the memory T cells in multiple myeloma (MM) and how they may influence immune responses in patients that received immunomodulating drugs and check point therapy.

Are the immuno-stimulatory properties of Lenalidomide extinguished by co-administration of Dexamethasone?

Dexamethasone has been a mainstay of anti-myeloma therapy for 20 years. However, it is intensely immunosuppressive and may limit the efficacy of the immune system to control myeloma, and limit the exciting opportunities to use immune stimulating drug therapies such as Lenalidomide to maximize the fight against this disease.

Upcoming immunotherapeutic combinations for B-cell lymphoma

After initial introduction for B-cell lymphomas as adjuvant therapies to established cancer treatments, immune checkpoint inhibitors and other immunotherapies are now integrated in mainstream regimens, both in adult and pediatric patients. We here provide an overview of the current status of combination therapies for B-cell lymphoma, by in-depth analysis of combination therapy trials registered between 2015–2020. Our analysis provides new insight into the rapid evolution in lymphoma treatment, as propelled by new additions to the treatment arsenal. We conclude with prospects on upcoming clinical trials which will likely use systematic testing approaches of more combinations of established chemotherapy regimens with new agents, as well as new combinations of immunotherapy and targeted therapy. Future trials will be set up as basket or umbrella-type trials to facilitate the evaluation of new drugs targeting specific genetic changes in the tumor or associated immune microenvironment. As such, lymphoma patients will benefit by receiving more tailored treatment that is based on synergistic effects of chemotherapy combined with new agents targeting specific aspects of tumor biology and the immune system.

Immunotherapy and Immunomodulation in Myeloproliferative Neoplasms

Myeloproliferative neoplasms are characterized by chronic inflammation. The discovery of constitutively active JAK-STAT signaling associated with driver mutations has led to clinical and translational breakthroughs. Insights into the other pathways and novel factors of potential importance are being actively investigated. Various classes of agents with immunomodulating or immunosuppressive properties have been used with varying degrees of success in treating myeloproliferative neoplasms. Early clinical trials are investigating the feasibility, effectiveness, and safety of immune checkpoint inhibitors, cell-based immunotherapies, and SMAC mimetics. The dynamic landscape of immunotherapy and immunomodulation in myeloproliferative neoplasms is the topic of the present review.

Immunotherapy approaches targeting neuroblastoma

PURPOSE OF REVIEW

In the era of immune-oncology, a breakthrough in the field of pediatric solid tumor research has been the demonstration that immunotherapy for patients with high-risk neuroblastoma improves the event-free and overall survival. Immunotherapeutic approaches including a monoclonal antibody targeting the cell surface glycosphingolipid disialoganglioside and cytokines successfully eliminate minimal residual disease.

RECENT FINDINGS

Since this seminal discovery, clinical trials evaluating immunotherapy in combination with chemotherapy and cellular therapies have begun to demonstrate effectiveness in treatment of bulky disease. Broader knowledge has also been gained regarding immunotherapy-limiting side-effects. Furthermore, biologic studies in actively treated patients have contributed to our growing understanding of the underlying immunologic processes and mechanisms of tumor response and immune evasion.

SUMMARY

The example of neuroblastoma is beginning to demonstrate that various immunotherapies combined with more conventional anticancer treatments can be synergistic. These advancements pose new challenges to both clinical researchers and medical provider and herald a new era in pediatric cancer therapy.

Pomalidomide restores immune recognition of primary effusion lymphoma through upregulation of ICAM-1 and B7-2

Pomalidomide (Pom) is an immunomodulatory drug that has efficacy against Kaposi’s sarcoma, a tumor caused by Kaposi’s sarcoma-associated herpesvirus (KSHV). Pom also induces direct cytotoxicity in primary effusion lymphoma (PEL), a B-cell malignancy caused by KSHV, in part through downregulation of IRF4, cMyc, and CK1α as a result of its interaction with cereblon, a cellular E3 ubiquitin ligase. Additionally, Pom can reverse KSHV-induced downregulation of MHCI and co-stimulatory immune surface molecules ICAM-1 and B7-2 on PELs. Here, we show for the first time that Pom-induced increases in ICAM-1 and B7-2 on PEL cells lead to an increase in both T-cell activation and NK-mediated cytotoxicity against PEL. The increase in T-cell activation can be prevented by blocking ICAM-1 and/or B7-2 on the PEL cell surface, suggesting that both ICAM-1 and B7-2 are important for T-cell co-stimulation by PELs. To gain mechanistic insights into Pom’s effects on surface markers, we generated Pom-resistant (PomR) PEL cells, which showed about 90% reduction in cereblon protein level and only minimal changes in IRF4 and cMyc upon Pom treatment. Pom no longer upregulated ICAM-1 and B7-2 on the surface of PomR cells, nor did it increase T-cell and NK-cell activation. Cereblon-knockout cells behaved similarly to the pomR cells upon Pom-treatment, suggesting that Pom’s interaction with cereblon is necessary for these effects. Further mechanistic studies revealed PI3K signaling pathway as being important for Pom-induced increases in these molecules. These observations provide a rationale for the study of Pom as therapy in treating PEL and other KSHV-associated tumors.

Primary effusion lymphoma (PEL) is an aggressive B-cell lymphoma caused by Kaposi’s sarcoma-associated herpesvirus (KSHV). KSHV encodes various genes that enable infected cells to evade recognition and elimination by the immune system. PEL cells are poorly recognized by T-cells and NK cells, partly due to KSHV-induced downregulation of immune stimulatory surface molecules ICAM-1 and B7-2. We previously found that a cereblon-binding immunomodulatory drug pomalidomide (Pom) can restore the levels of these markers on PELs. Here, we show that the increases in ICAM-1 and B7-2 induced by Pom leads to a functional increase in the recognition and killing of PELs by both T-cells and NK cells. Further, exposure of both the PEL cells and T-cells to Pom lead to an even higher T-cell stimulation providing strong evidence that Pom could help PEL patients by providing specific immune-stimulatory effect. We further perform mechanistic studies and show that Pom’s cellular binding partner cereblon as well as the PI3K pathway are important for Pom-mediated increases in these surface markers.

Thalidomide combined with short-term low-dose glucocorticoid therapy for the treatment of severe COVID-19: A case-series study

Objectives

The aim was to evaluate the safety and effectiveness of thalidomide, an immunomodulatory agent, in combination with glucocorticoid, for the treatment of COVID-19 patients with life-threatening symptoms.

Methods

A nonrandomized comparative case series study was performed. Six patients received thalidomide 100 mg per day (with therapy lasting for ≥7 days) plus low-dose short-term dexamethasone, and 6 control patients matched with patients in the thalidomide group, received low-dose short-term treatment with dexamethasone alone. The main outcomes were: the duration of SARS-CoV-2 negative conversion from admission; length of hospital stay; and changes in inflammatory cytokine concentrations and lymphocyte subsets.

Results

The median thalidomide treatment time was 12.0 days. The median duration of SARS-CoV-2 negative conversion from admission and hospital stay length were briefer in the thalidomide group compared to the control group (respectively, 11.0 vs 23.0 days, P = 0.043; 18.5 vs 30.0 days, P = 0.043). The mean reduction rates at 7–10 days after treatment for serum interleukin-6 and interferon-γ concentrations were greater in the thalidomide group compared to the control group. Alterations in lymphocyte numbers in the subsets between the 2 groups were similar.

Conclusions

Thalidomide plus short-term glucocorticoid therapy is an effective and safe regimen for the treatment of severely ill COVID-19 patients. The mechanism of action is most likely inhibition of inflammatory cytokine production.

Acute Liver Rejection in a Multiple Myeloma Patient Treated with Lenalidomide

Herein we present a patient that underwent a liver transplant due to primary biliary cholangitis (PBC) and after 9 years developed multiple myeloma. Following the cessation of mycophenolate mofetil and 2 weeks after lenalidomide treatment was started, the patient experienced acute cellular rejection. The patient recovered after treatment with corticosteroids, resumption of mycophenolate mofetil, and cessation of lenalidomide. Lenalidomide-associated allograft rejection has been reported in other organs. However, this is the first case report of liver rejection induced by lenalidomide.

Immunotherapeutic and Targeted Approaches in Multiple Myeloma

The multiple myeloma (MM) therapeutic landscape has evolved significantly with the approval of numerous novel agents, including next generation proteasome inhibitors (PIs), immunomodulatory agents (IMIDs), and monoclonal antibodies (MoABs) targeting CD38 and SLAMF7. While these discoveries have led to an unprecedented improval in patient outcomes, the disease still remains incurable. Immunotherapeutic approaches have shown substantial promise in recent studies of chimeric antigen receptor T-cell (CAR T-cell) therapy, bispecific antibodies, and antibody drug conjugates targeting B-cell maturation antigen (BCMA). This review will highlight these novel and targeted therapies in MM, with particular focus on PIs, IMIDs, MoAb and BCMA-directed immunotherapy.

New drugs in early development for treating multiple myeloma: all that glitters is not gold

INTRODUCTION

The last twenty years have introduced new therapeutic agents for multiple myeloma (MM); these include proteasome inhibitors (PIs), immunomodulatory drugs (IMDs) and monoclonal antibodies (mAbs). However, MM remains incurable, hence there is an unmet need for new agents for the treatment of advanced refractory disease. New agents could also be used in early lines to achieve improved, more sustained remission.

AREAS COVERED

We review the most promising agents investigated in early-phase trials for the treatment of MM and provide an emphasis on new agents directed against well-known targets (new PIs, IMDs and anti-CD38 mAbs). Drugs that work through distinct and numerous mechanisms of action (e.g. pro-apoptotic agents and tyrosine kinase inhibitors) and innovative immunotherapeutic approaches are also described. The paper culminates with our perspective on therapeutic approaches on the horizon for this disease.

EXPERT OPINION

IMD iberdomide and the export protein inhibitor selinexor demonstrated efficacy in heavily pretreated patients who had no other therapeutic options. We expect that immunotherapy with anti-BCMA BTEs and ADCs will revolutionize the approach to treating the early stages of the disease. Data on venetoclax in t(11;14)-positive patients may pave the way for personalized therapy. Not all new agents under early clinical evaluation will be investigated in regulatory phase III trials; one of the most important challenges is to identify those that could make a difference.

Tumor Vasculature Targeted TNFα Therapy: Reversion of Microenvironment Anergy and Enhancement of the Anti-tumor Efficiency

Tumor cells and tumor-associated stromal cells such as immune, endothelial and mesenchimal cells create a Tumor Microenvironment (TME) which allows tumor cell promotion, growth and dissemination while dampening the anti-tumor immune response. Efficient anti-tumor interventions have to keep into consideration the complexity of the TME and take advantage of immunotherapy and chemotherapy combined approaches. Thus, the aim of tumor therapy is to directly hit tumor cells and reverse endothelial and immune cell anergy. Selective targeting of tumor vasculature using TNFα-associated peptides or antibody fragments in association with chemotherapeutic agents, has been shown to exert a potent stimulatory effect on endothelial cells as well as on innate and adaptive immune responses. These drug combinations reducing the dose of single agents employed have led to minimize the associated side effects. In this review, we will analyze different TNFα-mediated tumor vesseltargeted therapies in both humans and tumor mouse models, with emphasis on the role played by the cross-talk between natural killer and dendritic cells and on the ability of TNFα to trigger tumor vessel activation and normalization. The improvement of the TNFα-based therapy with anti-angiogenic immunomodulatory drugs that may convert the TME from immunosuppressive to immunostimulant, will be discussed as well.

A Pilot Study of Lenalidomide Maintenance Therapy after Autologous Transplantation in Relapsed or Refractory Classical Hodgkin Lymphoma

For patients with relapsed or refractory classical Hodgkin lymphoma (cHL), salvage chemotherapy followed by consolidation with autologous stem cell transplant (ASCT) remains the standard of care. Even with this aggressive treatment strategy, 5-year progression-free survival is ≤50%, and there remains interest in maintenance strategies to improve long-term disease-free survival. Lenalidomide is an immunomodulatory agent with demonstrated activity in multiple subtypes of lymphoma including cHL, and has also been shown to improve both progression-free and overall survival as maintenance therapy after ASCT in multiple myeloma. This multicenter study evaluated maintenance lenalidomide after ASCT for patients with cHL. Patients were enrolled 60 to 90 days post-transplant and received oral lenalidomide on days 1 to 28 of 28-day cycles for a maximum of 18 cycles. Lenalidomide was started at 15 mg daily and increased to maximum of 25 mg daily if tolerated. The primary objective of this study was to assess the feasibility of this regimen, with a goal <30% rate of discontinuation at or before cycle 12 for drug-related reasons. Twenty-seven patients were enrolled and 26 received at least 1 dose of lenalidomide. With a median follow-up of 51.3 months (range, 12.2 to 76.2 months), 23 of 26 patients were alive. Median event-free survival was 9.4 months and median progression-free survival had not been reached, with 17 of 26 patients (65.4%) remaining in remission at last follow-up. Excluding 4 patients who discontinued therapy for progression and 2 who discontinued due to noncompliance, the discontinuation rate at or before cycle 12 was 52%. Treatment was complicated by a high frequency of hematologic adverse events, with 15 patients (58%) experiencing grade 3 to 4 hematologic toxicity and 5 (19%) experiencing grade 4 hematologic toxicity. We conclude that the regimen of maintenance lenalidomide explored in this study is not feasible for patients with cHL immediately following ASCT. An alternative lenalidomide dose or schedule may be better tolerated following ASCT for patients with relapsed or refractory cHL.

Antimetastatic effects of thalidomide by inducing the functional maturation of peripheral natural killer cells

Thalidomide and its analogues are known as immunomodulatory drugs (IMiDs) that possess direct antimyeloma effects, in addition to other secondary effects, including antiangiogenic, antiinflammatory, and immunomodulatory effects. Although the involvement of natural killer (NK) cells in the antitumor effects of IMiDs has been reported, it is unclear whether IMiDs inhibit cancer cell metastasis by regulating the antitumor function of NK cells. In this study, we examined the protective effects of thalidomide against cancer metastasis by focusing on its immunomodulatory effects through NK cells. Using experimental lung metastasis models, we found that pharmacological effects of thalidomide on host cells, but not its direct anticancer tumor effects, are responsible for the inhibition of lung metastases. To exert the antimetastatic effects of thalidomide, both γ‐interferon (IFN‐γ) production and direct cytotoxicity of NK cells were essential, without notable contribution from T cells. In thalidomide‐treated mice, there was a significant increase in the terminally differentiated mature CD27^lo NK cells in the peripheral tissues and NK cells in thalidomide‐treated mice showed significantly higher cytotoxicity and IFN‐γ production. The NK cell expression of T‐bet was upregulated by thalidomide treatment and the downregulation of glycogen synthase kinase‐3β expression was observed in thalidomide‐treated NK cells. Collectively, our study suggests that thalidomide induces the functional maturation of peripheral NK cells through alteration of T‐bet expression to inhibit lung metastasis of cancer cells.

Targeting the Microenvironment in MDS: The Final Frontier

Myelodysplastic syndromes (MDS) are a heterogeneous group of malignant disorders of hematopoietic stem and progenitor cells (HSPC), mainly characterized by ineffective hematopoiesis leading to peripheral cytopenias and progressive bone marrow failure. While clonal dominance is nearly universal at diagnosis, most genetic mutations identified in patients with MDS do not provide a conspicuous advantage to the malignant cells. In this context, malignant cells alter their adjacent bone marrow microenvironment (BME) and rely on cell extrinsic factors to maintain clonal dominance. The profoundly disturbed BME favors the myelodysplastic cells and, most importantly is detrimental to normal hematopoietic cells. Thus, the MDS microenvironment not only contributes to the observed cytopenias seen in these patients but could also negatively impact the engraftment of normal, allogeneic HSPCs in patients with MDS undergoing bone marrow transplant. Therefore, successful therapies in MDS should not only target the malignant cells but also reprogram their bone marrow microenvironment. Here, we will provide a synopsis of how drugs currently used or on the verge of being approved for the treatment of MDS may achieve this goal.