Two novel assays demonstrate persistent daratumumab exposure in a pediatric patient with delayed engraftment following allogeneic hematopoietic stem cell transplantation.

BACKGROUND AIMS: Daratumumab, a human IgG monoclonal antibody targeting CD38, is a promising treatment for pediatric patients with relapsed or refractory T-cell acute lymphoblastic leukemia (T-ALL). We describe a case of delayed engraftment following a mismatched, unrelated donor hematopoietic stem cell transplant (HSCT) in a 14-year-old female with relapsed T-ALL, treated with daratumumab and chemotherapy. By Day 28 post-HSCT, the patient had no neutrophil engraftment but full donor myeloid chimerism. METHODS: We developed two novel, semi-quantitative, antibody-based assays to measure the patient's bound and plasma daratumumab levels to determine if prolonged drug exposure may have contributed to her slow engraftment. RESULTS: Daratumumab levels were significantly elevated more than 30 days after the patient's final infusion, and levels inversely correlated with her white blood cell counts. To clear daratumumab, the patient underwent several rounds of plasmapheresis and subsequently engrafted. CONCLUSIONS: This is the first report of both delayed daratumumab clearance and delayed stem cell engraftment following daratumumab treatment in a pediatric patient. Further investigation is needed to elucidate the optimal dosing of daratumumab for treatment of acute leukemias in pediatric populations as well as daratumumab's potential effects on hematopoietic stem cells and stem cell engraftment following allogenic HSCT.

Challenging and target-based shifting strategies for heart failure treatment: An update from the last decades.

Heart failure (HF) is a major global health problem afflicting millions worldwide. Despite the significant advances in therapies and prevention, HF still carries very high morbidity and mortality, requiring enormous healthcare-related expenditure, and the search for new weapons goes on. Following initial treatment strategies targeting inotropism and congestion, attention has focused on offsetting the neurohormonal overactivation and three main therapies, including angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor antagonists, ß-adrenoceptor antagonists, and mineralocorticoid receptor antagonists, have been the foundation of standard treatment for patients with HF. Recently, a paradigm shift, including angiotensin receptor-neprilysin inhibitor, sodium glucose co-transporter 2 inhibitor, and ivabradine, has been added. Moreover, soluble guanylate cyclase stimulator, elamipretide, and omecamtiv mecarbil have come out as a next-generation therapeutic agent for patients with HF. Although these pharmacologic therapies have been significantly successful in relieving symptoms, there is still no complete cure for HF. We may be currently entering a new era of treatment for HF with animal experiments and human clinical trials assessing the value of antibody-based immunotherapy and gene therapy as a novel therapeutic strategy. Such tempting therapies still have some challenges to be addressed but may become a weighty option for treatment of HF. This review article will compile the paradigm shifts in HF treatment over the past dozen years or so and illustrate current landscape of antibody-based immunotherapy and gene therapy as a new therapeutic algorithm for patients with HF.

Incidence, duration, and severity of neutropenia in adults with B-cell acute lymphoblastic leukemia receiving blinatumomab consolidation.

Blinatumomab is a CD3 × CD19 antibody approved for adults with B-cell acute lymphoblastic leukemia (B-ALL). Blinatumomab is not considered myelosuppressive, but significant neutropenia has been seen in practice. We reviewed 95 patients with B-ALL who received blinatumomab at Dana-Farber Cancer Institute between 2015 and 2024. Of these, 71 patients were treated in morphologic remission with absolute neutrophil count (ANC) ≥1 × 109/L, for which 41% experienced grade ≥3 neutropenia and 13% developed ANC <0.1 × 109/L during blinatumomab. Neutropenia occurred more frequently during cycle 2 than cycle 1, and neutropenia did not necessarily portend worse neutropenia in later cycles. Multivariable analysis did not identify concurrent tyrosine kinase inhibitor use as a significant covariate for neutropenia. The nine patients who experienced ANC <0.1 × 109/L did not develop serious infections and received supportive care. Neutropenia occurs frequently and may be severe in patients with B-ALL who receive blinatumomab during remission, but complications appear manageable.

COVID-19 antibody titers after tixagevimab-cilgavimab injection in patients with hematologic diseases; a single-center, prospective study.

Knowledge of the SARS-CoV-2 antibody titers induced by tixagevimab-cilgavimab in patients with hematologic diseases remains insufficient. Here, we performed a single-center, prospective study to reveal the changes in antibody titer after administration of tixagevimab-cilgavimab in 78 patients with hematologic diseases. The median peak titer was 155.4 U/mL, and the median AUC was 46556 days·U/mL. First, we compared several characteristics between patients with low titers (peak titer ≤ 155.4 U/mL) and high titers (peak titer > 155.4 U/mL). We extracted 6 factors (patient age, sex, ECOG-PS, serum albumin level, and cross-sectional area and computed tomographic number of the psoas major muscle) as candidates influencing the antibody titers. Multiple regression analysis revealed that antibody titer was closely associated with these 6 factors (contribution rate = 0.76, p = 0.02). Our data support the inability of tixagevimab-cilgavimab to induce sufficient antibody titers against SARS-CoV-2, especially in older, frailer, female patients.

A Dual-domain Engineered Antibody for Efficient HBV Suppression and Immune Responses Restoration.

Chronic hepatitis B (CHB) remains a major public health concern because of the inefficiency of currently approved therapies in clearing the hepatitis B surface antigen (HBsAg). Antibody-based regimens have demonstrated potency regarding virus neutralization and HBsAg clearance. However, high dosages or frequent dosing are required for virologic control. In this study, a dual-domain-engineered anti-hepatitis B virus (HBV) therapeutic antibody 73-DY is developed that exhibits significantly improved efficacy regarding both serum and intrahepatic viral clearance. In HBV-tolerant mice, administration of a single dose of 73-DY at 2 mg kg-1 is sufficient to reduce serum HBsAg by over 3 log10 IU mL-1 and suppress HBsAg to < 100 IU mL-1 for two weeks, demonstrating a dose-lowering advantage of at least tenfold. Furthermore, 10 mg kg-1 of 73-DY sustainably suppressed serum viral levels to undetectable levels for ≈ 2 weeks. Molecular analyses indicate that the improved efficacy exhibited by 73-DY is attributable to the synergy between fragment antigen binding (Fab) and fragment crystallizable (Fc) engineering, which conferred sustained viral suppression and robust viral eradication, respectively. Long-term immunotherapy with reverse chimeric 73-DY facilitated the restoration of anti-HBV immune responses. This study provides a foundation for the development of next-generation antibody-based CHB therapies.

SLAMF7 as a Promising Immunotherapeutic Target in Multiple Myeloma Treatments.

Multiple myeloma (MM) is a common hematological malignancy that has fostered several new therapeutic approaches to combat newly diagnosed or relapsed MM. While the field has advanced over the past 2 decades, the majority of patients will develop resistance to these treatments, causing the need for new therapeutic targets. SLAMF7 is an attractive therapeutic target in multiple myeloma, and a monoclonal antibody that targets SLAMF7 has shown consistent beneficial outcomes in clinical trials to date. In this review, we will focus on the structure and regulation of SLAMF7 and its mechanism of action. The most recent clinical trials will be reviewed to further understand the clinical implications and improve the prognosis of MM. Furthermore, the efficacy of anti-SLAMF7 monoclonal antibodies combined with standard therapies and possible resistance mechanisms will be discussed. This review aimed to provide a detailed summary of the role of SLAMF7 in the pathogenesis of patients with MM and the rationale for further investigation into SLAMF7-mediated molecular pathways associated with MM development.

A phase I/II trial of brentuximab vedotin plus rituximab as frontline therapy for patients with immunosuppression-associated CD30+ and/or EBV + lymphomas.

Treatment strategies for post-transplant lymphoproliferative disorders (PTLD) consist of response-adapted risk-stratified methods using immunosuppression reduction, immunotherapy, and chemotherapy. We investigated the efficacy of Brentuximab vedotin given concurrently with Rituximab (BV + R) once weekly for four weeks, followed by optional consolidation, and up to one year of maintenance. Among 20 assessable patients, BV + R therapy resulted in an overall response rate of 75% (95% CI 51 to 91, p = 0.044) with 60% achieving a complete response. Median time to best response was 28 days. Two-year progression-free survival and overall survival rates were 75 and 90%, respectively. Most common severe grade 3/4 treatment-related toxicities included neutropenia (40%), hypertension (30%), infection (25%), and peripheral neuropathy (15%). BV + R is a novel and effective therapeutic strategy that achieved rapid and durable remissions in previously untreated PTLD patients; however, this treatment platform requires further modification due to the high rates of treatment-related toxicity.Key pointsBrentuximab vedotin + Rituximab showed ORR and CR rates of 75 and 60% in patients with immunosuppression-associated lymphoid malignanciesHigh rates of treatment delay were attributed to treatment-related toxicity; further dosing optimization of this regimen is required.

A single center retrospective study of daratumumab, pomalidomide, and dexamethasone as 2nd-line therapy in multiple myeloma.

Daratumumab, pomalidomide, and dexamethasone (DPd) is an FDA-approved 3rd or later line of therapy for myeloma. However, as there are limited published data on the efficacy of 2nd-line DPd, we conducted a retrospective analysis (n = 33). Herein, we report our center's data for 2nd-line DPd. Our patient population had a high amount of high risk cytogenetics (45.5%). The overall response rate (ORR) was 84.9% with a 1-year Progression Free Survival (PFS) of 37.7%. In standard risk myeloma (n = 18), the ORR was 88.9% and 1-year PFS was 61.1% (95% CI 42.3-88.3%). In high risk myeloma (45.5%, n = 15), the ORR was 80% with a 1-year PFS of 7.3% (95% CI 1.1-47.9%). This suggests that the efficacy of 2nd-line DPd in myeloma with high risk cytogenetics should be further investigated.

Management and outcomes of sinus histiocytosis with massive lymphadenopathy (Rosai Dorfman Disease).

Sinus histiocytosis with massive lymphadenopathy (Rosai Dorfman Disease [RDD]), is a rare, benign but clinically heterogeneous histiocytic disorder. Our aims were to analyze the clinical characteristics of the disease and explore the outcomes of patients with RDD followed at our institution. Between January 2000 and February 2019, there were 15 patients with a pathologically confirmed diagnosis of RDD. Median age at diagnosis was 48 years old (range 26-78). The majority (87%, n = 13) of the patients had extranodal disease. Frontline approaches included surgical intervention/complete excision (n = 5, 33%), rituximab monotherapy (n = 5, 33%), observation (n = 3, 20%), and radiation (n = 2, 13%). Two of the five patients underwent surgical excision and were subsequently treated with rituximab. Of the 7 patients who were given rituximab, 64% remained progression free 24 months after the initial rituximab administration. Our review parallels previous reports and highlights rituximab as a favorable option for therapy if ineligible for surgery or radiation.

Colonic mucosa-associated lymphoid tissue lymphoma: a case series.

Primary colonic mucosa-associated lymphoid tissue (MALT) lymphoma accounts for less than 0.5% of all colon cancers. We report 9 cases of colonic MALT lymphomas (median follow up: 9 [IQR 1-26] years). The disease was multi-focal in 4 patients: the most frequent sites were the cecum in 4 and the rectum in 3 patients. The main endoscopic finding was a polypoid lesion. The treatment modalities were rituximab +/- an alkylating agent (n = 5), an alkylating agent alone (n = 2), surgical resection (n = 1), and endoscopic resection (n = 1). Remission was achieved in 8 cases. Three patients relapsed, and 2 were re-treated. At the end of the study period, 67% of the patients were in remission. All patients were symptom-free. This current series of colonic MALT lymphomas shows the indolent nature of the disease, which may be treated with various modalities.

Recent advances in the treatment of acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is a heterogeneous disease with a bimodal distribution. The progresses made in understanding its biology led to the development of targeted therapies. In this review, we summarize the current and future approaches in management of adult ALL. Tyrosine kinase inhibitors (TKI) targeting BCR-ABL1 tyrosine kinase, monoclonal antibodies targeting cell surface antigens (CD19, CD20, and CD22), bispecific antibodies, and chimeric antigen receptor (CAR)-T therapy are breakthrough treatments. They resulted in FDA approvals of blinatumomab in 2014, inotuzumab ozagamicin in 2017, and tisagenlecleucel in 2017 for relapsed/refractory ALL. Currently, long-term survival is achieved in more than 50% of patients with precursor B-ALL (50-70% in patients with Philadelphia chromosome (Ph)-positive ALL), 50-60% T-ALL, and 80% mature B-ALL. Ongoing efforts exist to optimize therapeutic options in both the relapsed/refractory as well as the frontline settings. In the era of precision medicine, the future lies in using less cytotoxic and more targeted agents.

Complement as a Biological Tool to Control Tumor Growth.

Deposits of complement components have been documented in several human tumors suggesting a potential involvement of the complement system in tumor immune surveillance. In vitro and in vivo studies have revealed a double role played by this system in tumor progression. Complement activation in the cancer microenvironment has been shown to promote cancer growth through the release of the chemotactic peptide C5a recruiting myeloid suppressor cells. There is also evidence that tumor progression can be controlled by complement activated on the surface of cancer cells through one of the three pathways of complement activation. The aim of this review is to discuss the protective role of complement in cancer with special focus on the beneficial effect of complement-fixing antibodies that are efficient activators of the classical pathway and contribute to inhibit tumor expansion as a result of MAC-mediated cancer cell killing and complement-mediated inflammatory process. Cancer cells are heterogeneous in their susceptibility to complement-induced killing that generally depends on stable and relatively high expression of the antigen and the ability of therapeutic antibodies to activate complement. A new generation of monoclonal antibodies are being developed with structural modification leading to hexamer formation and enhanced complement activation. An important progress in cancer immunotherapy has been made with the generation of bispecific antibodies targeting tumor antigens and able to neutralize complement regulators overexpressed on cancer cells. A great effort is being devoted to implementing combined therapy of traditional approaches based on surgery, chemotherapy and radiotherapy and complement-fixing therapeutic antibodies. An effective control of tumor growth by complement is likely to be obtained on residual cancer cells following conventional therapy to reduce the tumor mass, prevent recurrences and avoid disabilities.

Brentuximab vedotin activity in diffuse large B-cell lymphoma with CD30 undetectable by visual assessment of conventional immunohistochemistry.

This phase 2 study evaluated brentuximab vedotin monotherapy in CD30-expressing DLBCL; after several patients with little to no CD30 achieved a complete remission (CR), the study evaluated treatment of DLBCL with undetectable CD30 (CD30u) by local visual immunohistochemistry (vIHC). Sixteen of 52 CD30u DLBCL patients (31%) had an objective response (6 CRs [12%]). Median progression-free survival (PFS) was 1.4 months (range, 0.4-15.6) and median overall survival (OS) was 7.5 months (range, 0.7-18.6+). Subsequent CD30 expression quantitated by computer-assisted digital image analysis (cIHC) showed that 11 of 16 CD30u DLBCL responders had ≥1% CD30. Correlative analyses of CD30u and CD30-expressing DLBCL combined demonstrated that ≥1% CD30 expression by cIHC resulted in a trend toward a higher response rate and significantly longer median PFS and OS. A minimum CD30 expression threshold appears to be required for antitumor activity in DLBCL; however, other factors also likely contribute to activity. (NCT01421667).

CS1 (SLAMF7, CD319) is an effective immunotherapeutic target for multiple myeloma.

CS1 (also known as CD319, CRACC and SLAMF7) was identified as an NK cell receptor regulating immune functions. It is also expressed on B cells, T cells, Dendritic cells, NK-T cells, and monocytes. CS1 is overexpressed in multiple myeloma and makes it a target for immunotherapy. A humanized anti-CS1 antibody, Elotuzumab or Empliciti has shown promising results in clinical studies. This review focuses on the biology of CS1 in NK and other hematopoietic cells and multiple myeloma. Anti-CS1 mAb can activate natural cytotoxicity of NK cells as well as enhance ADCC (antibody-dependent cell-mediated cytotoxicity) and thus makes an effective target for immunotherapy of MM.

Unexpected cross-reactivity of anti-cathepsin B antibodies leads to uncertainties regarding the mechanism of action of anti-CD20 monoclonal antibody GA101.

GA101, also known as obinutuzumab or Gazyva (Gazyvaro), is a glycoengineered type II humanized antibody that targets the CD20 antigen expressed at the surface of B-cells. This novel anti-CD20 antibody is currently assessed in clinical trials with promising results as a single agent or as part of therapeutic combinations for the treatment of B-cell malignancies. Detailed understanding of the mechanisms of GA101-induced cell death is needed to get insight into possible resistance mechanisms occurring in patients. Although multiple in vitro and in vivo mechanisms have been suggested to describe the effects of GA101 on B-cells, currently available data are ambiguous. The aim of our study was to clarify the cellular mechanisms involved in GA101-induced cell death in vitro, and more particularly the respective roles played by lysosomal and mitochondrial membrane permeabilization. Our results confirm previous reports suggesting that GA101 triggers homotypic adhesion and caspase-independent cell death, two processes that are dependent on actin remodeling and involve the production of reactive oxygen species. With respect to lysosomal membrane permeabilization (LMP), our data suggest that lack of specificity of available antibodies directed against cathepsin B may have confounded previously published results, possibly challenging current LMP-driven model of GA101 action mode.

Impact of time from diagnosis to initiation of curative chemotherapy on survival of patients with diffuse large B-cell lymphoma.

Although it is generally regarded appropriate to start chemotherapy promptly after a diagnosis of diffuse large B-cell lymphoma (DLBCL), the optimal time from diagnosis to treatment (TDT) is unknown. A total of 689 patients diagnosed with DLBCL and treated with ≥ 1 cycle of CHOP-R with curative intent during 2003-2008 in British Columbia were identified: 347 (50%) TDT ≤ 4 weeks, 277 (40%) TDT 5-8 weeks, 65 (10%) TDT > 8 weeks. For the respective TDT groups, 5-year OS estimates were 61%, 74%, 63% (p = 0.006); 5-year PFS 57%, 70%, 61% (p = 0.006); and 5-year DSS 64%, 80%, 77% (p <0.001). In multivariate analysis, TDT >8 weeks was associated with worse OS (HR 1.20 (95% CI 1.03, 1.41), p = 0.020), PFS (HR 1.33 (95% CI 1.15, 1.54), p < 0.001), and DSS (HR 1.40 (95% CI 1.10, 1.78), p = 0.006). Clinicians should endeavor to initiate curative chemotherapy as soon as possible after a diagnosis of DLBCL is established.

Treatment of multiple myeloma with the immunostimulatory SLAMF7 antibody elotuzumab.

Elotuzumab is a humanized monoclonal antibody targeting the extracellular domain of signaling lymphocytic activation molecule F7 (SLAMF7) highly expressed in multiple myeloma cells. Upon binding to myeloma cells, elotuzumab exerts its cytotoxic effects through antibody-dependent cellular cytotoxicity, the antibody-induced selective lysis of tumor cells by activated natural killer (NK) cells. Furthermore, elotuzumab has been shown to directly induce NK-cell activation by binding to SLAMF7 expressed on NK cells and to indirectly modulate T-cell function by promoting the secretion of cytokines from NK cells. In combination with lenalidomide and low-dose dexamethasone, elotuzumab has shown remarkable effects in patients with relapsed or refractory multiple myeloma. In these patients, the risk of disease progression or death was significantly reduced by 30% on elotuzumab. Currently, elotuzumab is being evaluated in various myeloma patient populations and combination regimens. This review discusses the use of elotuzumab as an antimultiple myeloma agent and provides an update on the results of recent clinical trials evaluating the safety and efficacy of elotuzumab for the treatment of multiple myeloma.

Spotlight on elotuzumab in the treatment of multiple myeloma: the evidence to date.

Despite advances in the treatment of multiple myeloma, it remains an incurable disease, with relapses and resistances frequently observed. Recently, immunotherapies, in particular, monoclonal antibodies, have become important treatment options in anticancer therapies. Elotuzumab is a humanized monoclonal antibody to signaling lymphocytic activation molecule F7, which is highly expressed on myeloma cells and, to a lower extent, on selected leukocyte subsets such as natural killer cells. By directly activating natural killer cells and by antibody-dependent cell-mediated cytotoxicity, elotuzumab exhibits a dual mechanism of action leading to myeloma cell death with minimal effects on normal tissue. In several nonclinical models of multiple myeloma, elotuzumab was effective as a single agent and in combination with standard myeloma treatments, supporting the use of elotuzumab in patients. In combination with lenalidomide and dexamethasone, elotuzumab showed a significant increase in tumor response rates and progression-free survival in patients with relapsed and/or refractory multiple myeloma. This review summarizes the nonclinical and clinical development of elotuzumab as a single agent and in combination with established therapies for the treatment of multiple myeloma.

Tocilizumab for steroid refractory acute graft-versus-host disease.

Acute graft-versus-host-disease (aGVHD) is a frequent and often lethal complication of allogeneic hematopoietic stem cell transplant despite prophylaxis. Tocilizumab is a humanized anti-IL-6 receptor monoclonal antibody that has evidence of activity in patients with steroid refractory (SR) GVHD. We retrospectively report on nine patients with grade 3 or 4 SR aGVHD who received tocilizumab. Eight mg/kg of tocilizumab was administered intravenously every 3-4 weeks. aGVHD grading and responses were based on consensus criteria. Median age at transplant was 48 years. Five patients had alternate donor sources. Median time from aGVHD onset to tocilizumab administration was 44 days. Two patients had complete responses and two had partial responses. Median survival from start of tocilizumab was 26 days (range 13-1054). Our limited experience demonstrated an overall response rate of 44% (CR + PR); however, this response was not durable. Further studies are needed to determine the optimal time for tocilizumab initiation.

Recurrent Hodgkin lymphoma: toward a new definition of candidates for autologous stem cell transplant in the era of positron emission tomography scan and novel agents.

Standard treatment for patients with Hodgkin lymphoma (HL) unresponsive to upfront therapy or relapsing after primary treatment (RR-HL) consists of salvage chemotherapy followed by autologous stem cell transplant (ASCT). ASCT outcomes are essentially related to two factors: disease burden at the time of transplant and comorbidity status of the patient. Positron emission tomography (PET) scan is a very sensitive diagnostic instrument to measure disease status. In fact, a negative PET status before ASCT is a well-known positive prognostic factor in patients with RR-HL. The recent introduction of the biologically targeted agent brentuximab vedotin has allowed us to treat RR-HL more efficaciously with less toxicity for the patient. Use of this new agent could help achieve a PET-negative status before ASCT in a larger percentage of patients, without severe toxicities, thereby improving ASCT outcomes. Herein we discuss the current evolving scenario of RR-HL treatment.