Anti-BCMA CAR T-Cell Therapy bb2121 in Relapsed or Refractory Multiple Myeloma

Chimeric Antigen Receptor Cell Therapy: Overcoming Obstacles to Battle Cancer

Chimeric antigen receptors (CAR) are fusion proteins engineered from antigen recognition, signaling, and costimulatory domains that can be used to reprogram T cells to specifically target tumor cells expressing specific antigens. Current CAR-T cell technology utilizes the patient's own T cells to stably express CARs and has achieved exciting clinical success in the past few years. However, current CAR-T cell therapy still faces several challenges, including suboptimal persistence and potency, impaired trafficking to solid tumors, local immunosuppression within the tumor microenvironment and intrinsic toxicity associated with CAR-T cells. This review focuses on recent strategies to improve the clinical efficacy of CAR-T cell therapy and other exciting CAR approaches currently under investigation, including CAR natural killer (NK) and NKT cell therapies.

CAR-T treatment for hematological malignancies

Chimeric antigen receptor (CAR)-T-cell therapy has sparked a wave of optimism in hematological malignancies, reflected by the successful results of early clinical trials involving patients with pre-B-cell acute lymphoblastic leukemia, B-cell lymphomas and multiple myeloma. CAR-T-cell therapy is considered to be a novel immunotherapy treatment that has the potential for curing certain hematological cancers. However, as use of CAR-T-cell therapy has grown, new challenges have surfaced. These challenges include the process of manufacturing the CAR-T cells, the mechanisms of resistance that underlie disease relapse, adverse effects and cost. This review describes the published results of clinical trials and expected developments to overcome CAR-T resistance.

NK cells and CD38: Implication for (Immuno)Therapy in Plasma Cell Dyscrasias

Immunotherapy represents a promising new avenue for the treatment of multiple myeloma (MM) patients, particularly with the availability of Monoclonal Antibodies (mAbs) as anti-CD38 Daratumumab and Isatuximab and anti-SLAM-F7 Elotuzumab. Although a clear NK activation has been demonstrated for Elotuzumab, the effect of anti-CD38 mAbs on NK system is controversial. As a matter of fact, an initial reduction of NK cells number characterizes Daratumumab therapy, limiting the potential role of this subset on myeloma immunotherapy. In this paper we discuss the role of NK cells along with anti-CD38 therapy and their implication in plasma cell dyscrasias, showing that mechanisms triggered by anti-CD38 mAbs ultimately lead to the activation of the immune system against myeloma cell growth.

Indications for Hematopoietic Cell Transplantation and Immune Effector Cell Therapy: Guidelines from the American Society for Transplantation and Cellular Therapy

The American Society for Transplantation and Cellular Therapy (ASTCT) published its first white paper on indications for autologous and allogeneic hematopoietic cell transplantation (HCT) in 2015. It was identified at the time that periodic updates of indications would be required to stay abreast with state of the art and emerging indications and therapy. In recent years the field has not only seen an improvement in transplantation technology, thus widening the therapeutic scope of HCT, but additionally a whole new treatment strategy using modified immune effector cells, including chimeric antigen receptor T cells and engineered T-cell receptors, has emerged. The guidelines review committee of the ASTCT deemed it optimal to update the ASTCT recommendations for indications for HCT to include new data and to incorporate indications for immune effector cell therapy (IECT) where appropriate. The guidelines committee established a multiple stakeholder task force consisting of transplant experts, payer representatives, and a patient advocate to provide guidance on indications for HCT and IECT. This article presents the updated recommendations from the ASTCT on indications for HCT and IECT. Indications for HCT/IECT were categorized as (1) Standard of care, where indication is well defined and supported by evidence; (2) Standard of care, clinical evidence available, where large clinical trials and observational studies are not available but have been shown to be effective therapy; (3) Standard of care, rare indication, for rare diseases where demonstrated effectiveness exists but large clinical trials and observational studies are not feasible; (4) Developmental, for diseases where preclinical and/or early-phase clinical studies show HCT/IECT to be a promising treatment option; and (5) Not generally recommended, where available evidence does not support the routine use of HCT/IECT. The ASTCT will continue to periodically review these guidelines and update them as new evidence becomes available.

DCEP and bendamustine/prednisone as salvage therapy for quad- and penta-refractory multiple myeloma

Multiple myeloma (MM) almost invariably progresses through novel therapies. Patients with quad-refractory MM (refractory to bortezomib, carfilzomib, lenalidomide, and pomalidomide) and penta-refractory MM (additional refractoriness to daratumumab) have few treatment options. Two chemotherapy regimens, bendamustine/prednisone (BP) and dexamethasone, cyclophosphamide, etoposide, and cisplatin (DCEP), are often used in quad- and penta-refractory MM, but there are limited data on outcomes in this heavily pre-treated population. We conducted a single-center retrospective study to identify all patients who received DCEP and/or BP for quad- or penta-refractory MM. Disease response and refractoriness were defined by International Myeloma Working Group criteria. The primary endpoint was overall response rate (ORR). Secondary endpoints included overall survival (OS), progression-free survival (PFS), and duration of response (DOR). We identified 27 patients who received BP for quad- or penta-refractory MM. The median number of prior lines of therapy was 6. The ORR for BP was 26%. The median PFS for BP was 1.4 months (95% CI 1.1-1.6) and median OS was 8.7 months (95% CI 2.3-15.0). Patients treated with cyclophosphamide had less response to BP. Thirty-one patients received DCEP for quad-refractory or penta-refractory MM. The median number of prior treatment regimens was 8. The ORR to DCEP was 35%. The median PFS was 2.7 months (95% CI 1.5-3.8) and median OS was 6.2 months (95% CI 4.4-7.8). DCEP and BP retain efficacy in quad- and penta-refractory MM. Our analysis supports prospective study of these regimens, possibly in combination or in comparison with other agents in this area of unmet need.

Immunotherapy in Multiple Myeloma

Multiple myeloma is a complex disease and immune dysfunction has been known to play an important role in the disease pathogenesis, progression, and drug resistance. Recent efforts in drug development have been focused on immunotherapies to modify the MM disease process. Here, we summarize the emerging immunotherapies in the MM treatment landscape.

Latest treatment strategies aiming for a cure in transplant-eligible multiple myeloma patients: how I cure younger MM patients with lower cost

This article presents a practical overview of the treatment of younger, newly diagnosed multiple myeloma patients, focusing on novel treatment strategies. With the introduction of effective new agents, multiple myeloma is one of the most active and changing fields in clinical oncology. In addition, monitoring technology has become reliable and practical. Achieving and sustaining minimal residual disease negativity (MRD- ), such as multiparameter flow cytometry (MFC) < 10^-5, is one of the goals of therapy. MRD-  is significantly associated with prolonged progression-free survival, whereas MRD persistence (MRD +) is an independent factor for poor progression-free survival. Evidence from several recent studies evaluating modern therapy has further supported the positive correlation between depth of response and outcomes. Multiple myeloma can become a chronic illness with sustained MRD- in a significant number of patients. Our ultimate hope is to leverage tumoricidal-immunomodulatory sequential therapies and to cure a subset of our patients.

CAR T and CAR NK cells in multiple myeloma: Expanding the targets

Multiple myeloma (MM) is a haematologic malignancy with significant improvements in the overall survival over the last decade. However, patients still relapse and die due to a lack of treatment options. Ultimately, novel therapies with the potential for long term remissions are needed for patients with advanced MM. Research efforts for such immune therapies were not successful until recently when the first immunotherapies for MM were approved in 2015 and many more are under development. In this review, we focus on adoptive cell therapies including CAR T-cell and CAR NK-cell therapies for patients with MM. We will provide an update on clinical and translational advances with a focus on results from ongoing clinical trials with BCMA targeted cellular therapies and the development of other novel targets, changes in the manufacturing process, trials focusing on earlier lines of therapy and combinations with other therapies as well as off the shelf products.

Specific stimulation of T lymphocytes with erythropoietin for adoptive immunotherapy

In adoptive T-cell immunotherapy of cancer, expansion and persistence of effector cells is a key determinant of response. We tested whether T lymphocytes could be rendered sensitive to erythropoietin (Epo) through ectopic expression of its wild-type receptor or a truncated form (EpoRm), which augments Epo signaling in erythrocyte progenitors. Both receptors could be expressed in human T lymphocytes; Epo ligation induced STAT5 phosphorylation, which was abrogated by nontoxic concentrations of the JAK1/2 inhibitor ruxolitinib. EpoRm had higher expression and triggered more potent stimulation than its wild-type counterpart, including superior T-cell survival and proliferation. Using a bicistronic vector, we expressed EpoRm together with an anti-CD19-41BB-CD3ζ chimeric antigen receptor (CAR), while maintaining the functions of each receptor. In the presence of Epo, EpoRm-CAR T cells had greater ex vivo expansion than CAR T cells and killed CD19+ leukemic cells more effectively in long-term cultures. In immunodeficient mice, physiologic levels of murine Epo were sufficient to preferentially expand EpoRm-CAR T cells, yielding a significantly higher antileukemic activity. Thus, outfitting adoptive T cells with EpoRm should yield greater effector-to-target ratios with a smaller number of infused cells; Epo or ruxolitinib administration could be used to adjust their levels postinfusion, maximizing antitumor activity and minimizing toxicity.

Chimeric Antigen Receptor-T-Cell Therapy for B-Cell Hematological Malignancies: An Update of the Pivotal Clinical Trial Data

Chimeric antigen receptor (CAR)-T-cell therapy is an innovative form of adoptive cell therapy that has revolutionized the treatment of certain hematological malignancies, including B-cell non-Hodgkin lymphoma (NHL) and B-cell acute lymphoblastic leukemia (ALL). The treatment is currently also being studied in other B-cell neoplasms, including multiple myeloma (MM) and chronic lymphocytic leukemia (CLL). CD19 and B-cell maturation antigen (BCMA) have been the most popular target antigens for CAR-T-cell immunotherapy of these malignancies. This review will discuss the efficacy and toxicity data from the pivotal clinical studies of CD19- and BCMA-targeted CAR-T-cell therapies in relapsed/refractory B-cell malignancies (NHL, ALL, CLL) and MM, respectively.

Acute Kidney Injury after CAR-T Cell Therapy: Low Incidence and Rapid Recovery

Chimeric antigen receptor (CAR) T cell therapy using engineered cytotoxic T cells has shown promising responses in various hematologic malignancies. Cytokine release syndrome (CRS) and immune effector cell-associated neurologic syndrome (ICANS) are recognized toxicities of CAR-T, whereas kidney injury remains less well recognized. The objective of the present study was to identify the incidence of acute kidney injury (AKI) after CAR-T cell therapy, potential risk factors, and recovery of kidney function. We performed a retrospective review of 46 adult patients with non-Hodgkin lymphoma treated with CAR-T therapy between February 2018 and February 2019 at our institution. Serum creatinine values before CAR-T therapy through day 100 were used to assess AKI, as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria: grade 1, 1.5- to <2-fold of baseline; grade 2, 2- to <3-fold of baseline; grade 3, ≥3-fold of baseline. CRS and ICANS were graded using the consensus criteria of the American Society of Transplantation and Cellular Therapy. The overall incidence of CRS was 78.3% (95% confidence interval [CI], 66% to 90.5%), of whom 13% (95% CI, 3.3% to 22.8%) developed grade 3-4 CRS, whereas the overall incidence of ICANS was lower at 45.7% (95% CI, 3.1% to 60.3%). The cumulative incidence of any grade AKI by day 100 was 30% (95% CI, 16.9% to 43.9%), with a grade 1 AKI incidence of 21.7% (95% CI, 9.7% to 33.8%) and a grade 2-3 AKI incidence of 8.7% (95% CI, .4% to 17%). No patients developed severe AKI necessitating renal replacement therapy. Patients with previous autologous or allogeneic stem cell transplantation, those requiring intensive care unit level care and with grade 3-4 CRS had a higher incidence of AKI. Most patients recovered, with kidney function returning to baseline within 30 days. We conclude that with early recognition and management of CAR-T complications, the incidence of AKI is low, the severity of injury is mild, and most patients recover kidney function within 30 days.

Hematopoietic stem cell transplantation for blood cancers in the era of precision medicine and immunotherapy

Hematopoietic stem cell transplantation (HCT) has been an integral component in the treatment of many hematologic malignancies. Since the development of HCT nearly 50 years ago, the role of this modality has evolved as newer treatment approaches have been developed and integrated into the standard of care. In the last decade, novel and highly active targeted therapies and immunotherapies have been approved for many hematologic malignancies, raising the question of whether HCT continues to retain its prominent role in the treatment paradigms of various hematologic malignancies. In this review, the authors have described the current role of autologous and allogeneic HCT in the treatment of patients with acute leukemias, aggressive B-cell lymphomas, and multiple myeloma and discussed how novel targeted therapies and immunotherapies have changed the potential need, timing, and goal of HCT in patients with these diseases.

Key Aspects of the Immunobiology of Haploidentical Hematopoietic Cell Transplantation

Hematopoietic stem cell transplantation from a haploidentical donor is increasingly used and has become a standard donor option for patients lacking an appropriately matched sibling or unrelated donor. Historically, prohibitive immunological barriers resulting from the high degree of HLA-mismatch included graft-vs.-host disease (GVHD) and graft failure. These were overcome with increasingly sophisticated strategies to manipulate the sensitive balance between donor and recipient immune cells. Three different approaches are currently in clinical use: (a) ex vivo T-cell depletion resulting in grafts with defined immune cell content (b) extensive immunosuppression with a T-cell replete graft consisting of G-CSF primed bone marrow and PBSC (GIAC) (c) T-cell replete grafts with post-transplant cyclophosphamide (PTCy). Intriguing studies have recently elucidated the immunologic mechanisms by which PTCy prevents GVHD. Each approach uniquely affects post-transplant immune reconstitution which is critical for the control of post-transplant infections and relapse. NK-cells play a key role in haplo-HCT since they do not mediate GVHD but can successfully mediate a graft-vs.-leukemia effect. This effect is in part regulated by KIR receptors that inhibit NK cell cytotoxic function when binding to the appropriate HLA-class I ligands. In the context of an HLA-class I mismatch in haplo-HCT, lack of inhibition can contribute to NK-cell alloreactivity leading to enhanced anti-leukemic effect. Emerging work reveals immune evasion phenomena such as copy-neutral loss of heterozygosity of the incompatible HLA alleles as one of the major mechanisms of relapse. Relapse and infectious complications remain the leading causes impacting overall survival and are central to scientific advances seeking to improve haplo-HCT. Given that haploidentical donors can typically be readily approached to collect additional stem- or immune cells for the recipient, haplo-HCT represents a unique platform for cell- and immune-based therapies aimed at further reducing relapse and infections. The rapid advancements in our understanding of the immunobiology of haplo-HCT are therefore poised to lead to iterative innovations resulting in further improvement of outcomes with this compelling transplant modality.

B-cell maturation antigen (BCMA) in multiple myeloma: rationale for targeting and current therapeutic approaches

Despite considerable advances in the treatment of multiple myeloma (MM) in the last decade, a substantial proportion of patients do not respond to current therapies or have a short duration of response. Furthermore, these treatments can have notable morbidity and are not uniformly tolerated in all patients. As there is no cure for MM, patients eventually become resistant to therapies, leading to development of relapsed/refractory MM. Therefore, an unmet need exists for MM treatments with novel mechanisms of action that can provide durable responses, evade resistance to prior therapies, and/or are better tolerated. B-cell maturation antigen (BCMA) is preferentially expressed by mature B lymphocytes, and its overexpression and activation are associated with MM in preclinical models and humans, supporting its potential utility as a therapeutic target for MM. Moreover, the use of BCMA as a biomarker for MM is supported by its prognostic value, correlation with clinical status, and its ability to be used in traditionally difficult-to-monitor patient populations. Here, we review three common treatment modalities used to target BCMA in the treatment of MM: bispecific antibody constructs, antibody–drug conjugates, and chimeric antigen receptor (CAR)-modified T-cell therapy. We provide an overview of preliminary clinical data from trials using these therapies, including the BiTE® (bispecific T-cell engager) immuno-oncology therapy AMG 420, the antibody–drug conjugate GSK2857916, and several CAR T-cell therapeutic agents including bb2121, NIH CAR-BCMA, and LCAR-B38M. Notable antimyeloma activity and high minimal residual disease negativity rates have been observed with several of these treatments. These clinical data outline the potential for BCMA-targeted therapies to improve the treatment landscape for MM. Importantly, clinical results to date suggest that these therapies may hold promise for deep and durable responses and support further investigation in earlier lines of treatment, including newly diagnosed MM.

CD229 CAR T cells eliminate multiple myeloma and tumor propagating cells without fratricide

Multiple myeloma (MM) is a plasma cell malignancy and most patients eventually succumb to the disease. Chimeric antigen receptor (CAR) T cells targeting B-Cell Maturation Antigen (BCMA) on MM cells have shown high-response rates, but limited durability. CD229/LY9 is a cell surface receptor present on B and T lymphocytes that is universally and strongly expressed on MM plasma cells. Here, we develop CD229 CAR T cells that are highly active in vitro and in vivo against MM plasma cells, memory B cells, and MM-propagating cells. We do not observe fratricide during CD229 CAR T cell production, as CD229 is downregulated in T cells during activation. In addition, while CD229 CAR T cells target normal CD229^high T cells, they spare functional CD229^neg/low T cells. These findings indicate that CD229 CAR T cells may be an effective treatment for patients with MM.

Precision medicine for human cancers with Notch signaling dysregulation (Review)

NOTCH1, NOTCH2, NOTCH3 and NOTCH4 are transmembrane receptors that transduce juxtacrine signals of the delta‑like canonical Notch ligand (DLL)1, DLL3, DLL4, jagged canonical Notch ligand (JAG)1 and JAG2. Canonical Notch signaling activates the transcription of BMI1 proto‑oncogene polycomb ring finger, cyclin D1, CD44, cyclin dependent kinase inhibitor 1A, hes family bHLH transcription factor 1, hes related family bHLH transcription factor with YRPW motif 1, MYC, NOTCH3, RE1 silencing transcription factor and transcription factor 7 in a cellular context‑dependent manner, while non‑canonical Notch signaling activates NF‑κB and Rac family small GTPase 1. Notch signaling is aberrantly activated in breast cancer, non‑small‑cell lung cancer and hematological malignancies, such as T‑cell acute lymphoblastic leukemia and diffuse large B‑cell lymphoma. However, Notch signaling is inactivated in small‑cell lung cancer and squamous cell carcinomas. Loss‑of‑function NOTCH1 mutations are early events during esophageal tumorigenesis, whereas gain‑of‑function NOTCH1 mutations are late events during T‑cell leukemogenesis and B‑cell lymphomagenesis. Notch signaling cascades crosstalk with fibroblast growth factor and WNT signaling cascades in the tumor microenvironment to maintain cancer stem cells and remodel the tumor microenvironment. The Notch signaling network exerts oncogenic and tumor‑suppressive effects in a cancer stage‑ or (sub)type‑dependent manner. Small‑molecule γ‑secretase inhibitors (AL101, MRK‑560, nirogacestat and others) and antibody‑based biologics targeting Notch ligands or receptors [ABT‑165, AMG 119, rovalpituzumab tesirine (Rova‑T) and others] have been developed as investigational drugs. The DLL3‑targeting antibody‑drug conjugate (ADC) Rova‑T, and DLL3‑targeting chimeric antigen receptor‑modified T cells (CAR‑Ts), AMG 119, are promising anti‑cancer therapeutics, as are other ADCs or CAR‑Ts targeting tumor necrosis factor receptor superfamily member 17, CD19, CD22, CD30, CD79B, CD205, Claudin 18.2, fibroblast growth factor receptor (FGFR)2, FGFR3, receptor‑type tyrosine‑protein kinase FLT3, HER2, hepatocyte growth factor receptor, NECTIN4, inactive tyrosine‑protein kinase 7, inactive tyrosine‑protein kinase transmembrane receptor ROR1 and tumor‑associated calcium signal transducer 2. ADCs and CAR‑Ts could alter the therapeutic framework for refractory cancers, especially diffuse‑type gastric cancer, ovarian cancer and pancreatic cancer with peritoneal dissemination. Phase III clinical trials of Rova‑T for patients with small‑cell lung cancer and a phase III clinical trial of nirogacestat for patients with desmoid tumors are ongoing. Integration of human intelligence, cognitive computing and explainable artificial intelligence is necessary to construct a Notch‑related knowledge‑base and optimize Notch‑targeted therapy for patients with cancer.

Enhancing cancer immunotherapy with nanomedicine

Therapeutic targeting of the immune system in cancer is now a clinical reality and marked successes have been achieved, most notably through the use of checkpoint blockade antibodies and chimeric antigen receptor T cell therapy. However, efforts to develop new immunotherapy agents or combination treatments to increase the proportion of patients who benefit have met with challenges of limited efficacy and/or significant toxicity. Nanomedicines - therapeutics composed of or formulated in carrier materials typically smaller than 100 nm - were originally developed to increase the uptake of chemotherapy agents by tumours and to reduce their off-target toxicity. Here, we discuss how nanomedicine-based treatment strategies are well suited to immunotherapy on the basis of nanomaterials' ability to direct immunomodulators to tumours and lymphoid organs, to alter the way biologics engage with target immune cells and to accumulate in myeloid cells in tumours and systemic compartments. We also discuss early efforts towards clinical translation of nanomedicine-based immunotherapy.

Chimeric antigen receptor T-cell therapy for multiple myeloma

Chimeric antigen receptor (CAR) T cell therapy, an immunotherapy using gene-modified T cells, has recently made a big success. CAR T cells targeting CD19 is highly effective against B cell malignancies. Next good target for CAR T therapy is multiple myeloma. B cell maturation antigen has been proved to be a good target for CAR T cell therapy in early-phase clinical trials. We are also developing CAR T cells targeting a protein conformation that is preferentially detected in myeloma cells. In this review, I will summarize the state of art in the field of CAR T cell therapy against myeloma, and also present our effort to develop a new CAR T cell therapy.

Modern treatments and future directions for newly diagnosed multiple myeloma patients

Over the course of the past decade-plus, the therapy of newly diagnosed multiple myeloma has seen incredible advances in the domains of diagnostic evaluation, active medical therapy, and response evaluation. This manuscript reviews the evaluation and management of newly diagnosed active multiple myeloma, with a focus on major clinical trials and IMWG recommendations. The paper describes a current approach for the initial evaluation and workup for patients with putative active myeloma, with consideration towards potential MRD-directed therapeutic approaches and future clinical trials, and then discusses management with a focus on induction regimens with attention primarily to modern three and four-drug combinations for transplant-eligible and transplant-ineligible patients, and those with organ dysfunction. Finally, this article briefly reviews minimal residual disease directed therapy approaches, primarily in the context of whether eligible patients should be referred for high dose chemotherapy and autologous stem cell rescue. Maintenance therapy for both transplant eligible and ineligible patients is discussed elsewhere in this issue.

Acute Kidney Injury and Electrolyte Abnormalities After Chimeric Antigen Receptor T-Cell (CAR-T) Therapy for Diffuse Large B-Cell Lymphoma

RATIONALE & OBJECTIVE

Cytokine release syndrome is a well-known complication of chimeric antigen receptor T-cell (CAR-T) therapy and can lead to multiorgan dysfunction. However, the nephrotoxicity of CAR-T therapy is unknown. We aimed to characterize the occurrence, cause, and outcomes of acute kidney injury (AKI), along with the occurrence of electrolyte abnormalities, among adults with diffuse large B-cell lymphoma receiving CAR-T therapy.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

We reviewed the course of 78 adults receiving CAR-T therapy with axicabtagene ciloleucel or tisagenlecleucel at 2 major cancer centers between October 2017 and February 2019. Baseline demographics, comorbid conditions, medications, and laboratory values were obtained from electronic health records. AKI was defined using KDIGO (Kidney Disease: Improving Global Outcomes) criteria. The cause, clinical course, and outcome of AKI events and electrolyte abnormalities in the first 30 days after CAR-T infusion were characterized using data contained in electronic health records.

RESULTS

Among 78 patients receiving CAR-T therapy, cytokine release syndrome occurred in 85%, of whom 62% were treated with tocilizumab. AKI occurred in 15 patients (19%): 8 had decreased kidney perfusion, 6 developed acute tubular necrosis, and 1 patient had urinary obstruction related to disease progression. Those with acute tubular necrosis and obstruction had the longest lengths of stay and highest 60-day mortality. Electrolyte abnormalities were common; hypophosphatemia, hypokalemia, and hyponatremia occurred in 75%, 56%, and 51% of patients, respectively.

LIMITATIONS

Small sample size; AKI adjudicated by retrospective chart review; lack of biopsy data.

CONCLUSIONS

In this case series of patients with diffuse large B-cell lymphoma receiving CAR-T therapy, AKI and electrolyte abnormalities occurred commonly in the context of cytokine release syndrome.

B cell maturation antigen-specific chimeric antigen receptor T cells for relapsed or refractory multiple myeloma: A meta-analysis

INTRODUCTION

Chimeric antigen receptor (CAR) T cells targeting B cell maturation antigen (BCMA) have shown impressive results in clinical studies for relapsed/refractory multiple myeloma (RRMM). We performed a systematic literature review to summarize the current body of evidence on the role of anti-BCMA CAR T cells for RRMM.

OBJECTIVES AND METHODS

Fifteen studies comprising a total of 285 patients with heavily pretreated RRMM were included using a conventional meta-analysis. Main efficacy outcomes were response, relapse, and survival. Safety outcomes were cytokine release syndrome (CRS) and neurotoxicity.

RESULTS

Anti-BCMA CAR T cells resulted in a pooled overall response of 82% (95% confidence interval [CI], 74%-88%) and complete response of 36% (24%-50%). Higher CAR⁺ cell doses were associated with higher response rates. The pooled relapse rate of responders was 45% (27%-64%), and median progression-free survival was 10 months. Present extramedullary disease did not show worse outcome. Severe CRS grades 3-4 and neurotoxicity occurred in 15% (10%-23%) and 18% (10%-31%).

CONCLUSION

Anti-BCMA CAR T cells showed high response rates, even in patients with present extramedullary disease, while relapse occurred in half of the patients who achieved a response. Larger studies with longer follow-up especially evaluating the association of response and survival are needed.

Monitoring minimal residual disease in the bone marrow using next generation sequencing

Achieving minimal residual disease (MRD) negativity in the bone marrow is one of the strongest prognostic factors in multiple myeloma. Consequently, MRD testing is routinely performed in clinical trials and moving towards standard of care. This review focuses on the role of next generation sequencing (NGS) of tumor-specific immunoglobulin V(D)J sequences for MRD tracking. The immunoglobulin variable regions are ideal targets for tracking, because every tumor cell shares an identical gene sequence, which is stable over time and generally distinct from the immunoglobulin sequences of normal B-cells. Several excellent assays for NGS-based MRD testing are available, both commercial and community-based, including one that is FDA-approved. These assays can achieve the gold standard analytical sensitivity of one tumor cell per million (10^-6), requiring a minimum input of 3 million bone marrow cells. On-going clinical trials will outline how MRD testing should be used to inform dynamic risk-adopted therapy.

Anti-BCMA chimeric antigen receptors with fully human heavy-chain-only antigen recognition domains

Chimeric antigen receptor (CAR)-expressing T cells targeting B-cell maturation antigen (BCMA) have activity against multiple myeloma, but improvements in anti-BCMA CARs are needed. We demonstrated recipient anti-CAR T-cell responses against a murine single-chain variable fragment (scFv) used clinically in anti-BCMA CARs. To bypass potential anti-CAR immunogenicity and to reduce CAR binding domain size, here we designed CARs with antigen-recognition domains consisting of only a fully human heavy-chain variable domain without a light-chain domain. A CAR designated FHVH33-CD8BBZ contains a fully human heavy-chain variable domain (FHVH) plus 4-1BB and CD3ζ domains. T cells expressing FHVH33-CD8BBZ exhibit similar cytokine release, degranulation, and mouse tumor eradication as a CAR that is identical except for substitution of a scFv for FHVH33. Inclusion of 4-1BB is critical for reducing activation-induced cell death and promoting survival of T cells expressing FHVH33-containing CARs. Our results indicate that heavy-chain-only anti-BCMA CARs are suitable for evaluation in a clinical trial.

Limited treatment options in refractory multiple myeloma: promising therapeutic developments

Introduction: Combinations of proteasome inhibitors, immunomodulators, and monoclonal antibodies are highly active against multiple myeloma. Consequently, several combinations have moved from the relapsed to the front-line setting. In the context of lenalidomide and bortezomib being used upfront, salvage options need to be evaluated.Areas covered: This manuscript reviews available data for the treatment of patients progressing on optimal frontline strategies, with a focus on the role of second-generation proteasome inhibitors and immunomodulators, monoclonal antibodies and immunotherapy.Expert opinion: Remarkable progress has been made in myeloma treatment due to the integration of immunomodulators, proteasome inhibitors and more recently monoclonal antibodies in the front-line setting. However, we work on the assumption that most individuals will eventually relapse. Optimized upfront therapy negatively selects more resistant patients among still relapsing individuals. Bortezomib and lenalidomide-exposed patients are under-represented in trials leading to currently approved combinations. Evidence needs to be reviewed taking into account how the improvement of frontline therapy has modified the characteristics of patients at the time of relapse. Second generation immunomodulatory agents and proteasome inhibitors, monoclonal antibodies and other agents have shown efficacy in this new landscape. Immunotherapeutic agents, including CAR-T cells are promising for patients failing standard combinations, despite current data are still immature.

Anti-B-Cell Maturation Antigen BiTE Molecule AMG 420 Induces Responses in Multiple Myeloma

PURPOSE

The anti-B-cell maturation antigen BiTE molecule AMG 420 was assessed in patients with relapsed/refractory multiple myeloma.

PATIENTS AND METHODS

In this first-in-human study, up to 10 cycles of AMG 420 were given (4-week infusions/6-week cycles). Patients had progression after ≥ 2 lines of prior therapy and no extramedullary disease. Minimal residual disease (MRD) response was defined as < 1 tumor cell/10⁴ bone marrow cells by flow cytometry.

RESULTS

Forty-two patients received AMG 420 at 0.2-800 μg/d. Median age was 65 years, and median disease duration was 5.2 years. Median exposure was 1 cycle (range, 1-10 cycles) and 7 cycles (range, 1-10 cycles) for responders. Patients discontinued for disease progression (n = 25), adverse events (AEs; n = 7), death (n = 4), completion of 10 cycles (n = 3), and consent withdrawal (n = 1). Two patients remain on treatment. There were 2 nontreatment-related deaths from AEs, influenza/aspergillosis and adenovirus-related hepatitis. Serious AEs (n = 20; 48%) included infections (n = 14) and polyneuropathy (n = 2); treatment-related serious AEs included 2 grade 3 polyneuropathies and 1 grade 3 edema. There were no grade ≥ 3 CNS toxicities or anti-AMG 420 antibodies. In this study, 800 μg/d was considered to not be tolerable because of 1 instance each of grade 3 cytokine release syndrome and grade 3 polyneuropathy, both of which resolved. The overall response rate was 31% (n = 13 of 42). At the maximum tolerated dose (MTD) of 400 μg/d, the response rate was 70% (n = 7 of 10). Of these, five patients experienced MRD-negative complete responses, and 1 had a partial response, and 1 had a very good partial response; all 7 patients responded during the first cycle, and some responses lasted > 1 year.

CONCLUSION

In this study of AMG 420 in patients with relapsed/refractory multiple myeloma, the response rate was 70%, including 50% MRD-negative complete responses, at 400 μg/d, the MTD for this study.

Current advances in chimeric antigen receptor T-cell therapy for refractory/relapsed multiple myeloma

Multiple myeloma (MM), considered an incurable hematological malignancy, is characterized by its clonal evolution of malignant plasma cells. Although the application of autologous stem cell transplantation (ASCT) and the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have doubled the median overall survival to eight years, relapsed and refractory diseases are still frequent events in the course of MM. To achieve a durable and deep remission, immunotherapy modalities have been developed for relapsed/refractory multiple myeloma (RRMM). Among these approaches, chimeric antigen receptor (CAR) T-cell therapy is the most promising star, based on the results of previous success in B-cell neoplasms. In this immunotherapy, autologous T cells are engineered to express an artificial receptor which targets a tumor-associated antigen and initiates the T-cell killing procedure. Tisagenlecleucel and Axicabtagene, targeting the CD19 antigen, are the two pacesetters of CAR T-cell products. They were approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of acute lymphocytic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). Their development enabled unparalleled efficacy in combating hematopoietic neoplasms. In this review article, we summarize six promising candidate antigens in MM that can be targeted by CARs and discuss some noteworthy studies of the safety profile of current CAR T-cell therapy.

Summary of the Third Annual Blood and Marrow Transplant Clinical Trials Network Myeloma Intergroup Workshop on Minimal Residual Disease and Immune Profiling

The third annual Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Myeloma Intergroup Workshop on Minimal Residual Disease and Immune Profiling was held on November 29, 2018, at the American Society of Hematology (ASH) annual meeting. This workshop featured the latest research focused on minimal residual disease (MRD) assessment and immune profiling (IP) in myeloma as well as discussion of the statistical and regulatory issues intrinsic to the development of MRD as a surrogate endpoint. In this report, we provide a summary of the workshop and focus on the integration of MRD and IP assessment into trial design and clinical practice.

Current challenges and emerging opportunities of CAR-T cell therapies

Infusion of chimeric antigen receptor (CAR)-genetically modified T cells (CAR-T cells) have led to remarkable clinical responses and cancer remission in patients suffering from relapsed or refractory B-cell malignancies. This is a new form of adoptive T cell therapy (ACT), whereby the artificial CAR enables the redirection of T cells endogenous antitumor activity towards a predefined tumor-associated antigen, leading to the elimination of a specific tumor. The early success in blood cancers has prompted the US Food and Drug Administration (FDA) to approve the first CAR-T cell therapies for the treatment of CD19-positive leukemias and lymphomas in 2017. Despite the emergence of CAR-T cells as one of the latest breakthroughs of cancer immunotherapies, their wider application has been hampered by specific life-threatening toxicities, and a substantial lack of efficacy in the treatment of solid tumors, owing to the strong immunosuppressive tumor microenvironment and the paucity of reliable tumor-specific targets. Herein, besides providing an overview of the emerging CAR-technologies and current clinical applications, the major hurdles of CAR-T cell therapies will be discussed, namely treatment-related life-threatening toxicities and the obstacles posed by the immunosupressive tumor-microenvironment of solid tumors, as well as the next-generation strategies currently designed to simultaneously improve safety and efficacy of CAR-T cell therapies in vivo.

Chimeric Antigen Receptor T-Cell Therapy for Cancer and Heart: JACC Council Perspectives

Chimeric antigen receptor (CAR) T-cell therapy has significantly advanced the treatment of patients with relapsed and refractory hematologic malignancies and is increasingly investigated as a therapeutic option of other malignancies. The main adverse effect of CAR T-cell therapy is potentially life-threatening cytokine release syndrome (CRS). Clinical cardiovascular (CV) manifestations of CRS include tachycardia, hypotension, troponin elevation, reduced left ventricular ejection fraction, pulmonary edema, and cardiogenic shock. Although insults related to CRS toxicity might be transient and reversible in most instances in patients with adequate CV reserve, they can be particularly challenging in higher-risk, often elderly patients with pre-existing CV disease. As the use of CAR T-cell therapy expands to include a wider patient population, careful patient selection, pre-treatment cardiac evaluation, and CV risk stratification should be considered within the CAR T-cell treatment protocol. Early diagnosis and management of CV complications in patients with CRS require awareness and multidisciplinary collaboration.

Chimeric Antigen Receptor T-Cell Therapy for Multiple Myeloma

CD19 Chimeric antigen receptor (CAR) T cell therapy has been shown to be effective for B cell leukemia and lymphoma. Many researchers are now trying to develop CAR T cells for various types of cancer. For multiple myeloma (MM), B-cell maturation antigen (BCMA) has been recently proved to be a promising target. However, cure of MM is still difficult, and several other targets, for example immunoglobulin kappa chain, SLAM Family Member 7 (SLAMF7), or G-protein coupled receptor family C group 5 member D (GPRC5D), are being tested as targets for CAR T cells. We also reported that the activated integrin β7 can serve as a specific target for CAR T cells against MM, and are preparing a clinical trial. In this review, we summarized current status of CAR T cell therapy for MM and discussed about the future perspectives.

Bispecific antibodies in cancer immunotherapy

Among antibody-based cancer therapies, bispecific antibodies (biAbs) have gained momentum in preclinical and clinical investigations following the regulatory approvals of the trailblazing T-cell engaging biAb (T-biAb) blinatumomab. Discussed herein are recent strategies that aim at boosting the potency and mitigating the toxicity of T-biAbs, broadening their therapeutic utility from hematologic to solid malignancies, and generating T-biAbs in situ. In cancer immunotherapy, T-biAbs are facing fierce competition with chimeric antigen receptor T cells (CAR-Ts), a battle for clinical and commercial viability that will be closely watched. However, innovative combinations of T-biAbs and CAR-Ts have also transpired. NK-cell engaging biAbs (NK-biAbs) are reemerging as an alternative that addresses liabilities of T-biAbs. Beyond NK-biAbs, other biAbs designed to recruit cellular and molecular components of the innate immune system will be covered in this reflection on new tools, technologies, and targets.

Immunotherapy for Multiple Myeloma

Despite therapeutic advances over the past decades, multiple myeloma (MM) remains a largely incurable disease with poor prognosis in high-risk patients, and thus new treatment strategies are needed to achieve treatment breakthroughs. MM represents various forms of impaired immune surveillance characterized by not only disrupted antibody production but also immune dysfunction of T, natural killer cells, and dendritic cells, although immunotherapeutic interventions such as allogeneic stem-cell transplantation and dendritic cell-based tumor vaccines were reported to prolong survival in limited populations of MM patients. Recently, epoch-making immunotherapies, i.e., immunomodulatory drug-intensified monoclonal antibodies, such as daratumumab combined with lenalidomide and chimeric antigen receptor T-cell therapy targeting B-cell maturation antigen, have been developed, and was shown to improve prognosis even in advanced-stage MM patients. Clinical trials using other antibody-based treatments, such as antibody drug-conjugate and bispecific antigen-directed CD3 T-cell engager targeting, are ongoing. The manipulation of anergic T-cells by checkpoint inhibitors, including an anti-T-cell immunoglobulin and ITIM domains (TIGIT) antibody, also has the potential to prolong survival times. Those new treatments or their combination will improve prognosis and possibly point toward a cure for MM.

Optimizing Manufacturing Protocols of Chimeric Antigen Receptor T Cells for Improved Anticancer Immunotherapy

Chimeric antigen receptor (CAR) T cell therapy can achieve outstanding response rates in heavily pretreated patients with hematological malignancies. However, relapses occur and they limit the efficacy of this promising treatment approach. The cellular composition and immunophenotype of the administered CART cells play a crucial role for therapeutic success. Less differentiated CART cells are associated with improved expansion, long-term in vivo persistence, and prolonged anti-tumor control. Furthermore, the ratio between CD4+ and CD8+ T cells has an effect on the anti-tumor activity of CART cells. The composition of the final cell product is not only influenced by the CART cell construct, but also by the culturing conditions during ex vivo T cell expansion. This includes different T cell activation strategies, cytokine supplementation, and specific pathway inhibition for the differentiation blockade. The optimal production process is not yet defined. In this review, we will discuss the use of different CART cell production strategies and the molecular background for the generation of improved CART cells in detail.

CAR T-cell therapy: is it prime time in myeloma?

Chimeric antigen receptor (CAR) T cells have shown promising activity in hematological malignancies and are being studied for the treatment of multiple myeloma, as well. B-cell maturation antigen, which is widely and almost exclusively expressed on plasma cells and B cells, is a promising target. Other targets being evaluated include CD19, CD38, CD138, signaling lymphocyte activation molecule or CS1, light chain, GPRC5D, and NKG2D. Early clinical studies have shown promising response rates in heavily pretreated patients, but relapses have occurred. Cytokine release syndrome and neurotoxicity have been observed in the majority of patients but are mostly grades 1 and 2. Relapse may be mediated by antigen escape and the limited persistence of CAR T cells. CAR T-cell constructs that target multiple antigens/epitopes or constructs with longer persistence due to a higher proportion of memory phenotype T cells may decrease the rates of relapse. Allogeneic CAR T cells that offer "off-the-shelf" options are also being developed. The challenges in integrating CAR T cells in myeloma therapy include disease relapse, adverse effects, cost, and identifying the right patient population. Longer-term data on efficacy and toxicity are needed before CAR T cells are ready for prime time in myeloma.

Anti-BCMA CAR T-cell therapy in multiple myeloma: can we do better?

Despite a substantial survival improvement and the availability of many new drugs in the last 2 decades, multiple myeloma (MM) remains largely incurable. Immunotherapeutic approaches are changing the current landscape in MM with B-cell maturation antigen (BCMA) as one of the most promising target antigens. Chimeric antigen receptor (CAR) T-cell therapy targeting BCMA produced unprecedented results in heavily pretreated relapsed and/or refractory MM. Data on more than 300 MM patients treated with anti-BCMA directed CAR T cells are available and these numbers are rapidly increasing. The response rate and the depth of responses induced by anti-BCMA CAR T cells are impressive; however, the majority of patients eventually relapse. Understanding the underlying mechanisms of response and resistance in treated MM patients will be critical to the rational development of this therapy. Moreover, the ideal place of this therapy in the treatment paradigm for MM is an important question that needs biological and clinical correlative data to help elucidate. T-cell-related, tumor-related and microenvironmental factors may play a role in the efficacy of anti-BCMA CAR T-cell therapy. In this review we summarize key clinical and correlative data on anti-BCMA CAR T-cell therapy. Based on available data we will try to highlight opportunities to further optimize this potential game-changing therapy for MM.