Odronextamab is a fully‐human IgG4‐based CD20xCD3 bispecific antibody that binds to CD3 on T cells and CD20 on B cells, triggering T‐cell‐mediated cytotoxicity independent of T‐cell‐receptor ...recognition. Adequate safety, tolerability, and encouraging durable complete responses have been observed in an ongoing first‐in‐human (FIH) study of odronextamab in patients with relapsed/refractory (R/R) B‐cell non‐Hodgkin lymphoma (B‐NHL; NCT02290951). We retrospectively evaluated the pharmacokinetic, pharmacodynamic, and antitumor characteristics of odronextamab in a series of in vitro/in vivo preclinical experiments, to assess their translational value to inform dose escalation for the FIH study. Half‐maximal effective concentration values from in vitro cytokine release assays (range: 0.05–0.08 mg/L) provided a reasonable estimate of odronextamab concentrations in patients associated with cytokine release at a 0.5 mg dose (maximum serum concentration: 0.081 mg/L) on week 1/day 1, which could therefore be used to determine the week 1 clinical dose. Odronextamab concentrations resulting in 100% inhibition of tumor growth in a Raji xenograft tumor mouse model (1–10 mg/L) were useful to predict efficacious concentrations in patients and inform dose‐escalation strategy. Although predicted human pharmacokinetic parameters derived from monkey data overestimated projected odronextamab exposure, they provided a conservative estimate for FIH starting doses. With step‐up dosing, the highest‐tested weekly odronextamab dose in patients (320 mg) exceeded the 1 mg/kg single dose in monkeys without step‐up dosing. In conclusion, combination of odronextamab in vitro cytokine data, efficacious concentration data from mouse tumor models, and pharmacokinetic evaluations in monkeys has translational value to inform odronextamab FIH study design in patients with R/R B‐NHL.
Odronextamab is a hinge-stabilised, fully human IgG4-based CD20 × CD3 bispecific antibody that binds CD3 on T cells and CD20 on B cells. We aimed to evaluate the safety and antitumour activity of ...odronextamab in patients with relapsed or refractory B-cell non-Hodgkin lymphoma.
This single-arm, multicentre, phase 1, dose-escalation and dose-expansion (ELM-1) trial was conducted at ten academic sites across the USA and Germany. Patients aged 18 years or older with CD20-positive relapsed or refractory B-cell malignancies who previously received CD20-directed antibody therapy and who had at least one measurable lesion, and an ECOG performance status of 0 or 1 were included. Patients received intravenous odronextamab, according to a step-up dosing schedule in cycle 1, followed by treatment once per week at target doses ranging from 0·1 mg to 320 mg during cycles 2-4 (each cycle was 21 days). After cycle 4, maintenance treatment occurred every 2 weeks until disease progression or unacceptable toxicity. The primary endpoint of safety was assessed by the incidence of adverse events and dose-limiting toxicities to determine the maximum tolerated dose or phase 2 dose of odronextamab, or both. Preliminary antitumour activity, as measured by objective response rate, was a secondary endpoint. This study is registered with ClinicalTrials.gov, NCT02290951.
From Feb 4, 2015, to Sept 25, 2021, 145 heavily pretreated patients (median of 3 (IQR 2-5 previous therapies) were enrolled (94 to the dose-escalation and 51 to the dose-expansion part of the study). The median age of patients was 67·0 years (IQR 57·0-73·0); 101 (70%) were male and 44 (30%) were female; most participants were White (119 82%) and not Hispanic or Latino (132 91%). 42 (29%) patients received previous CAR T therapy and 119 (82%) were refractory to the last line of therapy. Median duration of follow-up was 4·2 months (IQR 1·5-11·5). During dose escalation, odronextamab was administered up to the maximum dose of 320 mg once per week and no dose-limiting toxicities were observed. The recommended dose for expansion in patients with follicular lymphoma grade 1-3a was 80 mg and was 160 mg for patients with diffuse large B-cell lymphoma. Cytokine release syndrome and neurological treatment-emergent adverse events were predominantly low grade and did not result in treatment discontinuation. The most common grade 3 or worse treatment-emergent adverse events were anaemia (36 25%), lymphopenia (28 19%), hypophosphataemia (27 19%), neutropenia (27 19%), and thrombocytopenia (20 14%). Serious treatment-emergent adverse events occurred in 89 (61%) of 145 patients; the most frequent were cytokine release syndrome (41 28%), pyrexia (11 8%), pneumonia (nine 6%), and infusion-related reaction (six 4%). Four deaths were considered related to treatment (gastric perforation in a patient with gastric involvement by lymphoma, lung infection, pneumonia, and tumour-lysis syndrome). Objective response rate was 51% (95% CI 42-59; 72 of 142). In patients with follicular lymphoma who received odronextamab doses of 5 mg or higher, the objective response rate was 91% (95% CI 75-98; 29 of 32) and the complete response rate was 72% (95% CI 53-86; 23 of 32). In patients with diffuse large B-cell lymphoma without previous CAR T-cell therapy who received doses of 80 mg or higher, the objective response rate was 53% (eight of 15) and all responses were complete responses. In patients with diffuse large B-cell lymphoma who had previous CAR T-cell therapy and received doses of 80 mg or higher, the objective response rate was 33% (ten of 30) and complete response rate was 27% (eight of 30).
Odronextamab monotherapy showed a manageable safety profile and encouraging preliminary activity, including durable responses in heavily pretreated patients with B-cell non-Hodgkin lymphoma, supporting further clinical investigation in phase 2 and 3 trials.
Regeneron Pharmaceuticals.
Summary
Outcomes remain poor for patients with relapsed/refractory B‐cell non‐Hodgkin lymphoma (R/R B‐NHL). While chimeric antigen receptor (CAR) T‐cell therapy has revolutionised treatment, a ...significant proportion of patients relapse or fail to respond. Odronextamab is a CD20 × CD3 bispecific antibody that has demonstrated durable responses and a manageable safety profile in patients with R/R B‐NHL in a first‐in‐human trial (NCT02290951). Here, we document two patients with diffuse large B‐cell lymphoma refractory to CART‐cell therapy. Both achieved complete responses that remain ongoing for ≥2 years following odronextamab. Neither patient experienced Grade ≥3 cytokine release syndrome or Grade ≥3 neurological adverse events during treatment.
There is a growing interest in the pivotal role of exosomes in cancer and in their use as biomarkers. However, despite the importance of the microenvironment for cancer initiation and progression, ...monolayer cultures of tumor cells still represent the main in vitro source of exosomes. As a result, their environmental regulation remains largely unknown. Here, we report a three-dimensional tumor model for studying exosomes, using Ewing's sarcoma type 1 as a clinically relevant example. The bioengineered model was designed based on the hypothesis that the 3-dimensionality, composition and stiffness of the tumor matrix are the critical determinants of the size and cargo of exosomes released by the cancer cells. We analyzed the effects of the tumor microenvironment on exosomes, and the effects of exosomes on the non-cancer cells from the bone niche. Exosomes from the tissue-engineered tumor had similar size distribution as those in the patients' plasma, and were markedly smaller than those in monolayer cultures. Bioengineered tumors and the patients' plasma contained high levels of the Polycomb histone methyltransferase EZH2 mRNA relatively to their monolayer counterparts. Notably, EZH2 mRNA, a potential tumor biomarker detectable in blood plasma, could be transferred to the surrounding mesenchymal stem cells. This study provides the first evidence that an in vitro culture environment can recapitulate some properties of tumor exosomes.
BackgroundPatients with relapsed/refractory B-cell non-Hodgkin lymphoma (R/R B-NHL) have a significant need for effective treatment options. Odronextamab is an Fc-silenced, human, CD20×CD3 bispecific ...antibody that targets CD20-expressing cells via T-cell-mediated cytotoxicity independent of T-cell/major histocompatibility complex interaction. Phase I results in patients with R/R B-NHL demonstrated that odronextamab monotherapy could achieve deep and durable responses with a generally manageable safety profile (ELM-1; NCT02290951). As part of a biomarker analysis of the same study, we investigated potential biomarkers and mechanisms of resistance to odronextamab.MethodsPatients with R/R B-NHL enrolled in ELM-1 received one time per week doses of intravenous odronextamab for 4×21 day cycles, then doses every 2 weeks thereafter. Patient tumor biopsies were obtained at baseline, on-treatment, and at progression. Immune cell markers were analyzed by immunohistochemistry, flow cytometry, single-cell RNA sequencing, and whole genome sequencing.ResultsBaseline tumor biopsies showed that almost all patients had high proportions of B cells that expressed the CD20 target antigen, whereas expression of other B-cell surface antigens (CD19, CD22, CD79b) was more variable. Responses to odronextamab in patients with diffuse large B-cell lymphoma were not related to the relative level of baseline CD20 expression, cell of origin, or high-risk molecular subtype. A potential link was observed between greater tumor programmed cell death-ligand 1 expression and increased likelihood of response to odronextamab. Similarly, a trend was observed between clinical response and increased levels of CD8 T cells and regulatory T cells at baseline. We also identified an on-treatment pharmacodynamic shift in intratumoral immune cell subsets. Finally, loss of CD20 expression through inactivating gene mutations was identified as a potential mechanism of resistance in patients who were treated with odronextamab until progression, as highlighted in two detailed patient cases reported here.ConclusionsThis biomarker analysis expands on clinical findings of odronextamab in patients with R/R B-NHL, providing verification of the suitability of CD20 as a therapeutic target, as well as evidence for potential mechanisms of action and resistance.
Undifferentiated embryonal sarcoma of the liver (UESL) is a rare aggressive mesenchymal pediatric tumor. Previously, reported outcomes have been very poor. Here, we report a single‐center experience ...of five patients with UESL treated with upfront gross total resection and adjuvant chemotherapy. We have a median follow‐up of 8 years with a range from 5 to 19 years with 100% event‐free survival.
Ewing sarcoma is characterized by multiple deregulated pathways that mediate cell survival and proliferation. Heat shock protein 90 (HSP90) is a critical component of the multi-chaperone complexes ...that regulate the disposition and activity of a large number of proteins involved in cell-signaling systems. We tested the efficacy of PU-H71, a novel HSP90 inhibitor in Ewing sarcoma cell lines, primary samples, benign mesenchymal stromal cells and hematopoietic stem cells. We performed cell cycle analysis, clonogenic assay, immunoblot analysis and reverse phase protein array in Ewing cell lines and in vivo experiments in NSG and nude mice using the A673 cell line. We noted a significant therapeutic window in the activity of PU-H71 against Ewing cell lines and benign cells. PU-H71 treatment resulted in G2/M phase arrest. Exposure to PU-H71 resulted in depletion of critical proteins including AKT, pERK, RAF-1, c-MYC, c-KIT, IGF1R, hTERT and EWS-FLI1 in Ewing cell lines. Our results indicated that Ewing sarcoma tumor growth and the metastatic burden were significantly reduced in the mice injected with PU-H71 compared to the control mice. We also investigated the effects of bortezomib, a proteasome inhibitor, alone and in combination with PU-H71 in Ewing sarcoma. Combination index (CI)-Fa plots and normalized isobolograms indicated synergism between PU-H71 and bortezomib. Ewing sarcoma xenografts were significantly inhibited when mice were treated with the combination compared to vehicle or either drug alone. This provides a strong rationale for clinical evaluation of PU-H71 alone and in combination with bortezomib in Ewing sarcoma.
•PU-H71, a novel HSP90 inhibitor shows activity in Ewing sarcoma models.•PU-H71 treatment results in depletion of critical oncoproteins in Ewing sarcoma.•PU-H71 and bortezomib combination leads to accumulation of ubiquitinated proteins.•Combination of PU-H71 and bortezomib exhibits synergism in Ewing sarcoma models.
There is an unmet clinical need for improved tissue and liquid biopsy tools for cancer detection. We investigated the proteomic profile of extracellular vesicles and particles (EVPs) in 426 human ...samples from tissue explants (TEs), plasma, and other bodily fluids. Among traditional exosome markers, CD9, HSPA8, ALIX, and HSP90AB1 represent pan-EVP markers, while ACTB, MSN, and RAP1B are novel pan-EVP markers. To confirm that EVPs are ideal diagnostic tools, we analyzed proteomes of TE- (n = 151) and plasma-derived (n = 120) EVPs. Comparison of TE EVPs identified proteins (e.g., VCAN, TNC, and THBS2) that distinguish tumors from normal tissues with 90% sensitivity/94% specificity. Machine-learning classification of plasma-derived EVP cargo, including immunoglobulins, revealed 95% sensitivity/90% specificity in detecting cancer. Finally, we defined a panel of tumor-type-specific EVP proteins in TEs and plasma, which can classify tumors of unknown primary origin. Thus, EVP proteins can serve as reliable biomarkers for cancer detection and determining cancer type.
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•Proteomic profiles of extracellular vesicles and particles (EVPs) from 426 human samples•Identification of pan-EVP markers•Characterization of tumor-derived EVP markers in human tissues and plasma•EVP proteins can be useful for cancer detection and determining cancer type
A comprehensive proteomic analysis of extracellular vesicles and particles (EVPs) from 426 human samples identifies pan-EVP markers, biomarkers for EVP isolation, for cancer detection and determining cancer type.
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