This phase I dose-escalation/expansion study evaluated isatuximab (anti-CD38 monoclonal antibody) monotherapy in patients with relapsed/refractory multiple myeloma (RRMM). Patients progressing on or ...after standard therapy received intravenous isatuximab (weekly QW or every 2 weeks Q2W). The primary objective was to determine the maximum tolerated dose (MTD) of isatuximab. Overall, 84 patients received ≥ 1 dose of isatuximab. The MTD was not reached; no cumulative adverse reactions were noted. The most frequent adverse events were infusion reactions (IRs), occurring in 37/73 patients (51%) following introduction of mandatory prophylaxis. IRs were mostly grade 1/2, occurred predominantly during Cycle 1, and led to treatment discontinuation in two patients. CD38 receptor occupancy reached a plateau of 80% with isatuximab 20 mg/kg (highest dose tested) and was associated with clinical response. In patients receiving isatuximab ≥ 10 mg/kg, overall response rate (ORR) was 23.8% (15/63), including one complete response. In high-risk patients treated with isatuximab 10 mg/kg (QW or Q2W), ORR was 16.7% (3/18). Median (range) duration of response at doses ≥ 10 mg/kg was 25 (8-30) weeks among high-risk patients versus 36 (6-85) weeks for other patients. In conclusion, isatuximab demonstrated a manageable safety profile and clinical activity in patients with RRMM.
The zebrafish is a powerful model system for investigating embryonic vertebrate hematopoiesis, allowing for the critical in vivo analysis of cell lineage determination. In this study, we identify ...zebrafish myeloerythroid progenitor cells (MPCs) that are likely to represent the functional equivalent of mammalian common myeloid progenitors. Utilizing transgenic
pu.1-GFP fish, real-time MPC differentiation was correlated with dynamic changes in cell motility, morphology, and gene expression. Unlike mammalian hematopoiesis, embryonic zebrafish myelopoiesis and erythropoiesis occur in anatomically separate locations. Gene knockdown experiments and transplantation assays demonstrated the reciprocal negative regulation of
pu.1 and
gata1 and their non-cell-autonomous regulation that determines myeloid versus erythroid MPC fate in the distinct blood-forming regions. Furthermore, forced expression of
pu.1 in the bloodless mutant
cloche resulted in myelopoietic rescue, providing intriguing evidence that this gene can function in the absence of some stem cell genes, such as
scl, in governing myelopoiesis.
Local immunotherapy ideally stimulates immune responses against tumors while avoiding toxicities associated with systemic administration. Current strategies for tumor-targeted, gene-based delivery, ...however, are limited by adverse effects such as off-targeting or antivector immunity. We investigated the intratumoral administration of saline-formulated messenger (m)RNA encoding four cytokines that were identified as mediators of tumor regression across different tumor models: interleukin-12 (IL-12) single chain, interferon-α (IFN-α), granulocyte-macrophage colony-stimulating factor, and IL-15 sushi. Effective antitumor activity of these cytokines relied on multiple immune cell populations and was accompanied by intratumoral IFN-γ induction, systemic antigen-specific T cell expansion, increased granzyme B
T cell infiltration, and formation of immune memory. Antitumor activity extended beyond the treated lesions and inhibited growth of distant tumors and disseminated tumors. Combining the mRNAs with immunomodulatory antibodies enhanced antitumor responses in both injected and uninjected tumors, thus improving survival and tumor regression. Consequently, clinical testing of this cytokine-encoding mRNA mixture is now underway.
The zebrafish (
) has proven to be a powerful vertebrate model system for the genetic analysis of developmental pathways and is only beginning to be exploited as a model for human disease and ...clinical research. The attributes that have led to the emergence of the zebrafish as a preeminent embryological model, including its capacity for forward and reverse genetic analyses, provides a unique opportunity to uncover novel insights into the molecular genetics of cancer. Some of the advantages of the zebrafish animal model system include fecundity, with each female capable of laying 200-300 eggs per week, external fertilization that permits manipulation of embryos ex utero, and rapid development of optically clear embryos, which allows the direct observation of developing internal organs and tissues in vivo. The zebrafish is amenable to transgenic and both forward and reverse genetic strategies that can be used to identify or generate zebrafish models of different types of cancer and may also present significant advantages for the discovery of tumor suppressor genes that promote tumorigenesis when mutationally inactivated. Importantly, the transparency and accessibility of the zebrafish embryo allows the unprecedented direct analysis of pathologic processes in vivo, including neoplastic cell transformation and tumorigenic progression. Ultimately, high-throughput modifier screens based on zebrafish cancer models can lead to the identification of chemicals or genes involved in the suppression or prevention of the malignant phenotype. The identification of small molecules or gene products through such screens will serve as ideal entry points for novel drug development for the treatment of cancer. This review focuses on the current technology that takes advantage of the zebrafish model system to further our understanding of the genetic basis of cancer and its treatment.
Novel therapies are needed for effective treatment of AML. In the relapsed setting, prognosis is very poor despite salvage treatment with chemotherapy. Evidence suggests that leukemic stem cells ...(LSCs) cause relapse. The cell surface receptor CD123 is highly expressed in blast cells and LSCs from AML patients and is a potential therapeutic target. CD123 cross-over dual-variable domain T-cell engager (CD123-CODV-TCE) is a bispecific antibody with an innovative format. One arm targets the CD3εδ subunit of T-cell co-receptors on the surface of T cells, while the other targets CD123 on malignant cells, leading to cell-specific cytotoxic activity. Here, we describe the preclinical activity of CD123-CODV-TCE. CD123-CODV-TCE effectively binds to human and cynomolgus monkey CD3 and CD123 and is a highly potent T-cell engager. It mediates T-cell activation and T-cell-directed killing of AML cells in vitro. In vivo, CD123-CODV-TCE suppresses AML tumor growth in leukemia xenograft mouse models, where it achieves an effective half-life of 3.2 days, which is a significantly longer half-life compared to other bispecific antibodies with no associated Fc fragment. The in vitro safety profile is as expected for compounds with similar modes of action. These results suggest that CD123-CODV-TCE may be a promising therapy for patients with relapsed/refractory AML.
Mechanisms underlying the multiple developmental defects observed in Fanconi anemia (FA) patients are not well defined. We have identified the zebrafish homolog of human FANCD2, which encodes a ...nuclear effector protein that is monoubiquitinated in response to DNA damage, targeting it to nuclear foci where it preserves chromosomal integrity. Fancd2-deficient zebrafish embryos develop defects similar to those found in children with FA, including shortened body length, microcephaly, and microophthalmia, which are due to extensive cellular apoptosis. Developmental defects and increased apoptosis in Fancd2-deficient zebrafish were corrected by injection of human FANCD2 or zebrafish bcl2 mRNA, or by knockdown of p53, indicating that in the absence of Fancd2, developing tissues spontaneously undergo p53-dependent apoptosis. Thus, Fancd2 is essential during embryogenesis to prevent inappropriate apoptosis in neural cells and other tissues undergoing high levels of proliferative expansion, implicating this mechanism in the congenital abnormalities observed in human infants with FA.
The nuclear protein FOG-1 binds transcription factor GATA-1 to facilitate erythroid and megakaryocytic maturation. However, little is known about the function of FOG-1 during myeloid and lymphoid ...development or how FOG-1 expression is regulated in any tissue. We used in situ hybridization, gain- and loss-of-function studies in zebrafish to address these problems. Zebrafish FOG-1 is expressed in early hematopoietic cells, as well as heart, viscera, and paraspinal neurons, suggesting that it has multifaceted functions in organogenesis. We found that FOG-1 is dispensable for endoderm specification but is required for endoderm patterning affecting the expression of late-stage T-cell markers, independent of GATA-1. The suppression of FOG-1, in the presence of normal GATA-1 levels, induces severe anemia and thrombocytopenia and expands myeloid-progenitor cells, indicating that FOG-1 is required during erythroid/myeloid commitment. To functionally interrogate whether GATA-1 regulates FOG-1 in vivo, we used bioinformatics combined with transgenic assays. Thus, we identified 2 cis-regulatory elements that control the tissue-specific gene expression of FOG-1. One of these enhancers contains functional GATA-binding sites, indicating the potential for a regulatory loop in which GATA factors control the expression of their partner protein FOG-1.
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Background: ZL-1121 is a humanized immunoglobulin G1 monoclonal antibody targeting Claudin18.2. Site mutations (S239D and I332E) were introduced in the Fc portion of ZL-1211 to enhance antibody ...dependent cellular cytotoxicity. Herein, we present the preliminary results from the ongoing dose escalation part of the study. Methods: This is a first-in-human, phase 1/2, multicenter, dose escalation/cohort expansion study of ZL-1211 administered intravenously to adult patients with Claudin 18.2-positive advanced solid tumors. A Bayesian optimal interval design with 3+3 run-in was adopted to assess 5 dose levels of ZL-1211 monotherapy (1 to 40 mg/kg biweekly) for phase 1 dose escalation, followed by phase 2 cohort expansion. The primary objectives were to determine the maximum tolerated dose and/or the recommended phase 2 dose, assess the safety/tolerability, and evaluate the preliminary antitumor activities of ZL-1211. Tumor assessments were performed every 8 weeks per RECIST v1.1. Blood samples were collected for pharmacokinetic (PK) analyses. Results: As of Dec 12, 2022, 19 patients (11 pancreatic cancer, 6 gastric cancer, 1 esophageal cancer, and 1 bile duct cancer) had been enrolled in the dose escalation phase to receive ZL-1211 at 1 mg/kg (n = 3), 5 mg/kg (n = 7), 10 mg/kg (n = 4), and 20 mg/kg (n = 5). The median age was 60 years and the majority of the patients (78.9%) received ≥2 lines of prior systemic therapy. No dose limiting toxicities (DLT) had been observed as of the cut-off date. The most common treatment-related adverse events (TRAEs) were gastrointestinal disorders, including nausea (11/19, 57.9%), vomiting (6/19, 31.6%), and abdominal pain (3/19, 15.8%). Other common TRAEs (≥15%) were hypoalbuminaemia (3/19, 15.8%) and infusion-related reactions (3/19, 15.8%). Grade 3 TRAEs occurred in 3 patients, 1 with nausea and vomiting, 1 with platelet count decreased, and 1 with anaemia, leukopenia, platelet count decreased, and weight decreased. No Grade ≥ 4 TRAEs were reported. Two patients experienced serious TRAEs: 1 reporting 2 cases each of grade 3 vomiting and nausea and 1 reporting a grade 3 platelet count decreased and a grade 2 abdominal pain, all of which had recovered. TRAEs led to treatment interruption in 5 patients (26.3%) and treatment withdrawal in 1 patient (5.3%). No TRAEs leading to death were reported. Six of 9 tumor-evaluable patients achieved stable disease as the best overall response. Three patients had tumor regression: 17.1% in a pancreatic cancer patient of the 5 mg/kg cohort; 14.5% in a pancreatic cancer patient and 24.9% in a gastric cancer patient in the 10 mg/kg cohort. Preliminary PK analyses revealed linear PK of ZL-1211 over the dose range tested. Conclusions: ZL-1211 displayed an acceptable safety/tolerability profile to date and demonstrated preliminary antitumor effects. Clinical trial information: NCT05065710 .
Abstract Purpose In tumours with wild-type TP53 , the tumour-suppressive function of p53 is frequently inhibited by HDM2. This phase I, dose-escalating study investigated the maximum tolerated dose ...(MTD), safety, pharmacokinetics and pharmacodynamics of SAR405838, an HDM2 inhibitor, in patients with advanced solid tumours ( NCT01636479 ). Methods In dose escalation, patients with any locally advanced/metastatic solid tumour with TP53 mutation prevalence below 40%, or documented as TP53 wild-type, were eligible. In the MTD expansion cohort, only patients with de-differentiated liposarcoma were included. Primary end-points were MTD and efficacy in the MTD expansion cohort. Secondary end-points included safety, pharmacokinetics and pharmacodynamics biomarkers. Results Seventy-four patients were treated with SAR405838 (50–800 mg once daily QD, 800–1800 mg weekly and 1800 mg twice weekly). Two patients treated with SAR405838 400 mg QD had thrombocytopaenia as a dose-limiting toxicity (DLT). The MTD for the QD schedule of SAR405838 was 300 mg QD. No DLTs were observed with the weekly schedule; one patient had a DLT of nausea with the 1800 mg twice-weekly dose. Treatment with SAR405838 was associated with increased plasma MIC-1, reflecting p53 pathway activation. In the de-differentiated liposarcoma MTD cohort, 89% of the patients had HDM2 amplification at baseline and no TP53 mutations were observed; best response was stable disease in 56% and progression-free rate at 3 months was 32%. Conclusion SAR405838 had an acceptable safety profile with limited activity in patients with advanced solid tumours. The MTD of SAR405838 was 300 mg QD; MTD was not reached with the weekly schedule.
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