Search Results (384)

Background/Objectives: This study compared overall survival (OS) associated with common real-world treatment sequences in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) in the United States. Methods: Utilizing the nationwide Flatiron Health electronic health record-derived de-identified database, adult CLL/SLL patients who initiated systemic therapy (JAN2016-NOV2023) and received at least two lines of therapy (LoTs) were analyzed. Treatment regimens were categorized based on drug class, and most frequent (n ≥ 50) sequences (first LoT followed by [→] second LoT) were compared. OS from initiation of the first LoT was compared using multivariable Cox proportional hazard models, and adjusted hazard ratios with 95% CIs were reported. Results: Among 2354 eligible patients, n = 1711 (73%) received the 16 most frequent treatment sequences. Sequencing chemoimmunotherapy (CIT) → CIT (HR: 2.29 [1.23–4.28]), anti-CD20 monoclonal antibody (anti-CD20mab) monotherapy → CIT (1.95 [1.03–3.69]), and covalent Bruton tyrosine kinase inhibitor (cBTKi) monotherapy → anti-CD20mab monotherapy (2.00 [1.07–3.74]) were associated with worse OS compared to patients treated with cBTKi monotherapy → B-cell lymphoma 2 inhibitors (BCL2i) + anti-CD20mab (reference). Conclusions: OS associated with other sequences were not significantly different from the reference sequence in adjusted analyses, suggesting a lack of evidence for the optimal standard of care for sequencing the first two LoTs in real-world settings. Future research should reassess sequencing outcomes as novel treatments become adopted into clinical practice. Full article

CD26 (dipeptidyl peptidase-4) is a marker of colorectal cancer stem cells with high metastatic potential and resistance to therapy. Although CD26 expression is known to be associated with tumor progression, its functional involvement in epithelial-mesenchymal transition (EMT) and metastasis remains to be fully elucidated. In this study, we aimed to investigate the effects of a monoclonal anti-CD26 antibody on EMT-related phenotypes and metastatic behavior in colorectal cancer cells. We evaluated changes in EMT markers by quantitative PCR and Western blotting, assessed cell motility and invasion using scratch wound-healing and Transwell assays, and examined metastatic potential in vivo using a splenic injection mouse model. Treatment with the anti-CD26 antibody significantly increased the expression of the epithelial marker E-cadherin and reduced levels of EMT-inducing transcription factors, including ZEB1, Twist1, and Snail1, at the mRNA and protein levels. Functional assays revealed that the antibody markedly inhibited cell migration and invasion in vitro without exerting cytotoxic effects. Furthermore, systemic administration of the anti-CD26 antibody significantly suppressed the formation of liver metastases in vivo. These findings suggest that CD26 may contribute to the regulation of EMT and metastatic behavior in colorectal cancer. Our data highlight the potential therapeutic utility of CD26-targeted antibody therapy for suppressing EMT-associated phenotypes and metastatic progression. Full article

In today’s oncology, immunotherapy arises as a potent complement for conventional cancer treatment, allowing for obtaining better patient outcomes. B7-H3 (CD276) is a member of the B7 protein family, which emerged as an attractive target for the treatment of various tumors. The molecule modulates anti-cancer immune responses, acting through diverse signaling pathways and cell populations. It has been implicated in the pathogenesis of numerous malignancies, including melanoma, gliomas, lung cancer, gynecological cancers, renal cancer, gastrointestinal tumors, and others, fostering the immunosuppressive environment and marking worse prognosis for the patients. B7-H3 targeting therapies, such as monoclonal antibodies, antibody–drug conjugates, and CAR T-cells, present promising results in preclinical studies and are the subject of ongoing clinical trials. CAR-T therapies against B7-H3 have demonstrated utility in malignancies such as melanoma, glioblastoma, prostate cancer, and RCC. Moreover, ADCs targeting B7-H3 exerted cytotoxic effects on glioblastoma, neuroblastoma cells, prostate cancer, and craniopharyngioma models. B7-H3-targeting also delivers promising results in combined therapies, enhancing the response to other immune checkpoint inhibitors and giving hope for the development of approaches with minimized adverse effects. However, the strategies of B7-H3 blocking deliver substantial challenges, such as poorly understood molecular mechanisms behind B7-H3 protumor properties or therapy toxicity. In this review, we discuss B7-H3’s role in modulating immune responses, its significance for various malignancies, and clinical trials evaluating anti-B7-H3 immunotherapeutic strategies, focusing on the clinical potential of the molecule. Full article

Multiple myeloma (MM) is predominantly a disease of the elderly. In recent years, a surge of highly effective plasma cell therapies has revolutionized the care of elderly multiple myeloma (MM) patients, for whom frailty and age-related competing causes of mortality determine management. Traditionally, the treatment of newly diagnosed elderly patients has centered on doublet or triplet combinations composed of immunomodulators (IMIDs), proteasome inhibitors (PIs), anti-CD38 monoclonal antibodies (mAbs), and corticosteroids producing median progression-free survival (PFS) rates between 34 and 62 months. However, recently, a series of large phase III clinical trials examining quadruplet regimens of PIs, IMIDs, corticosteroids, and anti-CD38 mAbs have shown exceptional outcomes, with median PFS exceeding 60 months, albeit with higher rates of peripheral neuropathy (≥Grade 2: 27% vs. 10%) when PIs and IMIDs are combined, and infections (≥Grade 3: 40% vs. 29–41%) with the addition of anti-CD38mAbs. The development of T-cell redirecting therapies including T-cell engagers (TCEs) and CAR-T cells has further expanded the therapeutic arsenal. TCEs have shown exceptional activity in relapsed disease and are being explored in the newly diagnosed setting with promising early results. However, concerns remain regarding the logistical challenges of step-up dosing, which often necessitates inpatient admission, the infectious risks, and the financial burden associated with TCEs in elderly patients. CAR-T, the most potent commercially available therapy for MM, offers the potential of a ‘one and done’ approach. However, its application to elderly patients has been tempered by significant concerns of cytokine release syndrome, early and delayed neurological toxicity, and its overall tolerability in frail patients. Robust data in frail patients are still needed. How CAR-T and TCEs will be sequenced among the growing therapeutic armamentarium for elderly MM patients remains to be determined. This review explores the safety, efficacy, cost, and logistical barriers associated with the above treatments in elderly MM patients. Full article

The effective suppression of inflammation using disease-modifying therapies is essential in the treatment of multiple sclerosis (MS). Anti-CD20 monoclonal antibodies are commonly used long-term as maintenance therapies, largely due to the lack of reliable biomarkers to guide dosing and evaluate treatment response. However, prolonged use increases the risk of infections and other immune-mediated side effects. The unique ability of brain-derived blood extracellular vesicles (EVs) to cross the blood–brain barrier and reflect the central nervous system (CNS) immune status has sparked interest in their potential as biomarkers. This study aimed to assess whether blood-derived L1CAM⁺ EVs could serve as biomarkers of treatment response to rituximab (RTX) in patients with relapsing-remitting MS (RRMS). Serum samples (n = 25) from the baseline (month 0) and after 6 months were analyzed from the RTX arm of the ongoing randomized clinical trial OVERLORD-MS (comparing anti-CD20 therapies in RRMS patients) and were compared with serum samples from healthy controls (n = 15). Baseline cerebrospinal fluid (CSF) samples from the same study cohort were also included. EVs from both serum and CSF samples were characterized, considering morphology, size, and concentration, using transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). The immunophenotyping of EV surface receptors was performed using flow cytometry with the MACSPlex exosome kit, while label-free quantitative proteomics of EV protein cargo was conducted using a proximity extension assay (PEA). TEM confirmed the presence of EVs with the expected round morphology with a diameter of 50–150 nm. NTA showed significantly higher concentrations of L1CAM⁺ EVs (p < 0.0001) in serum total EVs and EBNA1⁺ EVs (p < 0.01) in serum L1CAM⁺ EVs at baseline (untreated) compared to in healthy controls. After six months of RTX therapy, there was a significant reduction in L1CAM⁺ EV concentration (p < 0.0001) and the downregulation of TNFRSF13B (p = 0.0004; FC = −0.49) in serum total EVs. Additionally, non-significant changes were observed in CD79B and CCL2 levels in serum L1CAM⁺ EVs at baseline compared to in controls and after six months of RTX therapy. In conclusion, L1CAM⁺ EVs in serum showed distinct immunological profiles before and after rituximab treatment, underscoring their potential as dynamic biomarkers for individualized anti-CD20 therapy in MS. Full article

Background/Objectives: Anti-drug antibody (ADA) formation can impact the safety, pharmacokinetics, and/or efficacy of biotherapeutics, including monoclonal antibodies (mAbs). Current strategies for ADA/immunogenicity risk prediction of mAbs include in silico algorithms, T cell proliferation assays, MHC-associated peptide proteomics assays (MAPPs), and dendritic cell internalization assays. However, B cell-mediated responses are not assessed in these assays. B cells are professional antigen-presenting cells (APCs) and secrete antibodies toward immunogenic mAbs. Therefore, methods to determine B cell responses would be beneficial for immunogenicity risk prediction and may provide a more comprehensive assessment of risk. Methods: We used a PBMC culture method with the addition of IL-4, IL-21, B cell activating factor (BAFF), and an anti-CD40 agonist mAb to support B cell survival and activation. Results: B cells in this assay format become activated, proliferate, and secrete IgG. A panel of 51 antibodies with varying clinical immunogenicity rates were screened in this assay with IgG secretion used as a readout for immunogenicity risk. IgG secretion differed among test articles but did not correlate with the clinical immunogenicity rating. Conclusions: This dataset highlights the challenges of developing a B cell assay for immunogenicity risk prediction and provides a framework for further refinement of a B cell-based assay for immunogenicity risk prediction of mAbs. Full article

Background/Objectives: Radiotherapy (RT) is a mainstay of clinical cancer therapy that causes broad immune responses. The complement system is a pivotal effector mechanism in the innate immune response, but the impact of RT is less well understood. This study investigates the interaction between RT and the complement system as a possible approach to improve immune responses in cancer treatment. Methods: Human solid cancer (lung, prostate, liver, breast cancer), lymphoma, and leukemia cells were irradiated using X-rays and treated with polyclonal antibodies or anti-CD20 monoclonal antibodies, respectively. Chromium release assay was applied to measure cell lysis after radiation with or without complement-activating antibody treatment. The expression of membrane-bound complement regulatory proteins (mCRPs; CD46, CD55, CD59), which confer resistance against complement activation, CD20 expression, apoptosis, and radiation-induced DNA double-strand breaks (γH2AX), was measured by flow cytometry. The radiosensitivity of tumor cells was assessed by colony-forming assay. Results: We demonstrate that RT profoundly impacts complement function by upregulating the expression of membrane-bound complement regulatory proteins (mCRPs) on tumor cells in a dose- and time-dependent manner. Impaired complement-mediated tumor cell lysis could thus potentially contribute to radiotherapeutic resistance. We also observed RT-induced upregulation of CD20 expression on lymphoma and leukemic cells. Notably, complement activation prior to RT proved more effective in inducing RT-dependent early apoptosis compared to post-irradiation treatment. While complement modulation does not significantly alter RT-induced DNA-damage repair mechanisms or intrinsic radiosensitivity in cancer cells, our results suggest that combining RT with complement-based anti-cancer therapy may enhance complement-dependent cytotoxicity (CDC) and apoptosis in tumor cells. Conclusions: This study sheds light on the complex interplay between RT and the complement system, offering insights into potential novel combinatorial therapeutic strategies and a potential sequential structure for certain tumor types. Full article

The rabbit is a widely used experimental model for human translational research and stem cell therapy. Many studies have focused on rabbit mesenchymal stem cells from different biological sources for their possible application in regenerative medicine. However, a minimal number of studies have been published aimed at rabbit hematopoietic stem/progenitor cells, mainly due to the lack of specific anti-rabbit CD34 antibodies. In general, CD34 antigen is commonly used to identify and isolate hematopoietic stem/progenitor cells in humans and other animal species. The aim of this study was to develop novel monoclonal antibodies highly specific to rabbit CD34 antigen. We used hybridoma technology, two synthetic peptides derived from predicted rabbit CD34 protein, and a recombinant rabbit CD34 protein as immunogens to produce monoclonal antibodies (mAbs) specific to rabbit CD34. The produced antibodies were screened for their binding activity and specificity using ELISA, flow cytometry, and Western blot analysis. Finally, four mAbs (58/47/26, 58/47/34, 182/7/80, and 575/36/8) were selected for the final purification process. The purified mAbs recognized up to 2–3% of total rabbit bone marrow cells, while about 2% of those cells exhibited CD45 expression, which are likely rabbit primitive hematopoietic stem cells and their hematopoietic progenitors, respectively. The newly generated and purified mAbs specifically recognize CD34 antigen in rabbit bone marrow or peripheral blood and can be therefore used for further immunological applications, to study rabbit hematopoiesis or to establish a new animal model for hematopoietic stem cell transplantation studies. Full article

The traditional paradigm of multiple sclerosis (MS) as a T cell-mediated disorder has been challenged by the effectiveness of monoclonal antibodies (mAbs) targeting CD20-expressing lymphocytes. Although these are mostly represented by B cells, the CD20 marker is expressed by 2–6% of T cells (CD20+ T), which are effectively depleted in serum and cerebrospinal fluid of MS patients by anti-CD20 mAbs. CD20+ T cells are characterized by a pro-inflammatory phenotype and increased potential for migrating and invading the central nervous system (CNS) compared to CD20− T cells. Furthermore, CD20+ T cells are detected within brain inflammatory lesions from MS patients and actively participate in the experimental MS model. This review aims to summarize the current knowledge on CD20+ T cells, from their identification and characterization to evidence of depletion by disease-modifying treatments (DMTs), likely contributing to therapeutic efficacy. Conflicting hypotheses on the origin and development of CD20+ T cells will also be discussed, as well as evidence from clinical and preclinical studies supporting their pathogenetic role in MS. Full article

Background: Chronic lymphocytic leukemia (CLL) is a prevalent hematologic malignancy that predominantly affects elderly individuals, posing significant clinical challenges due to patient comorbidities and inherent resistance to conventional chemotherapy. The emergence of targeted therapies combining venetoclax, a selective inhibitor of the anti-apoptotic protein BCL-2, with anti-CD20 monoclonal antibodies has dramatically transformed the treatment landscape. Methods: This retrospective observational study analyzed the differential impacts of first-line venetoclax-obinutuzumab (VenO) and second-line venetoclax-rituximab (VenR) on immunoglobulin G (IgG) levels and absolute neutrophil count (ANC) in CLL patients. Results: Our findings indicate that during first-line VenO therapy, a significant improvement in ANC levels from baseline was observed, whereas patients undergoing second-line VenR therapy demonstrated limited impact on ANC and the decreasing tendency in IgG levels. Patients treated with VenR had a longer disease history and previous exposure to other treatment regimens, primarily chemoimmunotherapy, which could negatively influence immune recovery, making direct comparisons between these two treatment lines challenging. Although this observational study did not directly compare infection rates, the observed enhancement of ANC levels in patients receiving VenO suggests a potential for lower infection risk compared to pretreated VenR patients. Conclusions: These results underscore the clinical significance of considering both the treatment line and the patient’s prior therapeutic history when selecting venetoclax-based regimens for CLL. The potential association of first-line VenO with improved immunological parameters and the complex impact of prior therapies on immunological recovery with second-line VenR warrant further prospective investigation into the correlation between treatment regimen, patient history, immune function, and infectious complications. Full article

Background/Objectives: The administration of human monoclonal antibodies (mAb) in preclinical pharmacokinetics and toxicology studies often triggers an immune response, leading to the formation of anti-drug antibodies (ADA). To mitigate this effect, we have recently performed and reported on studies using short-term immunosuppressive regimens to induce prolonged immune tolerance towards a human mAb, erenumab, in rats. Here, we report on the development of a semi-mechanistic modeling approach that quantitatively integrates pharmacokinetic and immunogenicity assessments from immune tolerance induction studies to provide a framework for the simulation-based evaluation of different immune induction scenarios for the maintenance of prolonged immune tolerance towards human mAbs. Methods: The integrated pharmacokinetic/pharmacodynamic (PK/PD) modeling approach combined a semi-mechanistic model of the adaptive immune system to predict ADA formation kinetics with a population pharmacokinetic model to assess the impact of the time course of the ADA magnitude on the PK of erenumab in rats. Model-derived erenumab concentration–time profiles served as input for a quantitative system pharmacology-style semi-mechanistic model of the adaptive immune system to conceptualize the ADA response as a function of the kinetics of CD4⁺ T helper cells and T regulatory cells. Results: The model adequately described the observed ADA magnitude–time profiles in all treatment groups and reasonably simulated the kinetics of selected immune cells responsible for ADA formation. It also successfully captured the impact of tacrolimus/sirolimus immunomodulation on ADA formation, demonstrating that the regimen effectively suppressed ADA formations and induced immune tolerance. Conclusions: This work demonstrates the utility of modeling approaches to integrate pharmacokinetic and immunogenicity assessment data for the prospective planning of long-term toxicology studies to support the preclinical development of mAbs. Full article

Recombinantly produced monoclonal antibodies (mabs) belong to the fastest growing class of biotherapeutics. In humans, antibodies are classified into five different classes: IgA, IgD, IgE, IgG and IgM. Most of the therapeutic mabs used in the clinic belong to the IgG class, albeit other antibody classes, e.g., IgM, have been evaluated in clinical stages. Antibodies are composed of heavy chains paired with a light chain. In IgM and IgA, an additional chain, the J-chain, is present. Two types of light chains exist in humans: the κ-light chain and the λ-light chain. The κ-light chain predominates in humans and is used in the vast majority of therapeutic IgG. The reason for the preference of the κ-light chain in humans is not known. Our study investigates whether light-chain selection influences the productivity of the clinically validated mabs adalimumab and trastuzumab. Both mabs were expressed as IgG and IgM with a κ- or a λ-light chain in HEK293 cells. Besides comparing the expression levels of the different mabs, we also evaluated whether the passage number of the cell line has an impact on product yield. In addition, the expressions of adalimumab, trastuzumab, an anti-CD38 and an anti-PD-L1-antibody were analyzed in HEK293 and CHO cells when both the κ- and λ-light chains are present. In summary, IgG outperformed IgM variants in expression efficacy, while light-chain selection had minimal impact on the overall expression levels. The yields of all mab variants were higher in fresh cells, despite cell cultures with a high cell passage number having higher cell densities and cell numbers at the time of harvest. The incorporation of a particular light chain occurred at similar rates in HEK293 and CHO cells. Full article

Pediatric-onset multiple sclerosis (POMS) is a rare yet increasingly recognized demyelinating disease of the central nervous system, characterized by a highly inflammatory disease course and an elevated relapse rate compared to adult-onset MS (AOMS). Given the unique immunopathogenesis of POMS, recent therapeutic strategies have shifted toward early initiation of high-efficacy disease-modifying therapies (DMTs) to minimize irreversible neurological damage. Among these, B-cell-targeting therapies, particularly anti-CD20 monoclonal antibodies, have shown efficacy in adult MS and are emerging as promising candidates for POMS treatment. The present review summarizes the current knowledge of the role of B-cells in POMS pathophysiology and evaluates the therapeutic potential of anti-CD-20 agents. It also highlights ongoing clinical trials and future perspectives, including novel B-cell-directed approaches such as anti-CD19 therapies, Bruton’s tyrosine kinase (BTK) inhibitors, and BAFF-targeting agents. Full article

Background: Recently, the addition of anti-CD38 monoclonal antibodies (mAbs) to standard first-line triplet regimens, including a proteasome inhibitor (PI), an immunomodulatory drug (IMiD) and dexamethasone, has led to the introduction of quadruplets in clinical practice. Methods: A systematic search was conducted (end-of-search: 9 November, 2024) for clinical trials investigating first-line anti-CD38 mAb-based quadruplets in combination with a PI and an IMiD. Pooled proportions and effect-estimates along with 95% confidence intervals were calculated with common-effect and random-effects models and further subgroup and meta-regression analyses were performed. Results: The pooled 2-, 3- and 4-year progression-free survival (PFS) rates were 89%, 77% and 86%, respectively. Furthermore, patients treated with quadruplets demonstrated a 46% reduced risk for disease progression or death (HR = 0.54, 95% CI: 0.46–0.64) compared to those on triplets. Overall survival (OS) rates were consistently high, ranging from 83% to 96% between different regimens. High rates of deep responses that deepened over time were observed, with the pooled proportion of patients achieving at least complete response being 64%. Importantly, the pooled MRD negativity rate was 62%, whereas patients treated with quadruplet first-line therapy had 2.5 times the odds to be MRD negative at any point compared with those on triplets. Moreover, the odds for sustained 12-month MRD negativity were thrice as much with quadruplets compared to triplets. Finally, while no increase in serious adverse events was observed with quadruplet regimens compared to triplets, a 46% statistically significant increased risk for grade 3–4 neutropenia and thrombocytopenia was observed, along with a 14% increased risk for grade 3–4 infections. Conclusions: The addition of anti-CD38 mAbs to standard triplet regimens has shown particularly favorable outcomes, supporting their integration in the upfront treatment of patients with NDMM. However, close monitoring for hematological toxicity and infections is essential. Full article

Triple-negative breast cancer (TNBC) is an aggressive cancer characterized by a high risk of recurrence, invasiveness, metastatic potential, and poor prognosis. Tumor-associated macrophages (TAMs), particularly M2-like TAMs, contribute to TNBC progression by promoting an immunosuppressive tumor microenvironment (TME), highlighting the need for TME remodeling. This study aimed to evaluate the therapeutic efficacy of co-administering CL7, a CD300c monoclonal antibody that induces M1 macrophage polarization, and anti-PD-1, an immune checkpoint inhibitor, in TNBC. To establish a TNBC model, 4T1 cells were inoculated into the fourth left mammary gland of mice. CL7 and anti-PD-1 were intravenously administered twice a week. Flow cytometry and RT-PCR were performed to assess the immunotherapeutic effects, and lung metastases were evaluated by the Hematoxylin and Eosin staining of lung tissues. Tumor growth was significantly reduced in the combination treatment group (CL7 and anti-PD-1) compared to both the PBS and monotherapy groups. Additionally, the combination treatment increased M1 macrophages and activated CD8+ T and NK cells in the tumor, while significantly suppressing lung metastases. These findings suggest that the combination of CL7 and anti-PD- therapy has the potential to treat TNBC by remodeling the TME. Full article