Macrophage-mediated Antibody-dependent Phagocytosis Research Articles

IgG antibodies mediated gold nanoparticles conjugated to methotrexate as targeted chemotherapy for lung cancer

Vincamine, a natural chemical, was used as a reducing agent in the synthesis of IgG antibodies mediated biogenic gold nanoparticles (IgGAuNPs). Eventually, the synthesised IgGAuNPs were bioconjugated with the chemotherapeutic drug methotrexate (MTX-IgGAuNPs). The IgG isotype can target cancer cells through polymorphic Fc gamma receptors (FcγRs) and have therapeutic effects. They can restrict cell division by inhibiting different intracellular signal transduction pathways and activating NK cells and macrophages through antibody-dependent cellular cytotoxicity and macrophage-mediated antibody-dependent phagocytosis, respectively. Further, IgGAuNPs and MTX-IgGAuNPs were characterised by physical techniques. Moreover, 3D conformational changes in the structure of IgG were analysed by fluorescence spectroscopy during and after the synthesis of IgGAuNPs. Furthermore, the IgGAuNPs and MTX-IgGAuNPs were effective against lung cancer (A549 cells), while they were found to be non-toxic against normal cells (NRK cells). The effectiveness of IgGAuNPs and MTX-IgGAuNPs was examined by MTT cytotoxicity assay, DCFDA method for the production of ROS, and release of Cyt-c from the mitochondria for caspase-3-mediated apoptosis. Moreover, the confirmation of internalisation of particles into the nucleus was examined under the DAPI assay, and it was found that particles caused nuclear fragmentation, which was also an indication of apoptosis.

Abstract 2957: CD127 is expressed by acute lymphoblastic leukemias and is efficiently targeted by the IL7R-antagonist OSE-127 through macrophage-mediated antibody dependent phagocytosis

Abstract Acute lymphoblastic leukemia (ALL) arises from the uncontrolled proliferation of precursor B or T cells (B- or T-ALL). Novel immunotherapies are urgently needed to reduce polychemotherapy-related toxicities and to target relapsed/refractory disease. The Interleukin 7 receptor (IL7R) plays a pivotal role in the development of ALL through mutations leading to constitutive activation of the oncogenic IL7R pathway or through overexpression of the receptor. The IL7Rα chain (CD127)-targeting antibody OSE-127 is a full antagonist of the IL7R pathway with an excellent safety profile (NCT03980080), currently evaluated in phase 2 trials in inflammatory and autoimmune diseases (NCT04882007, NCT04605978). We previously reported in vivo efficacy of OSE-127 in CD127+ ALL patient-derived xenografts (PDXs) and synergy with standard of care polychemotherapy, but we had not evaluated CD127 protein expression in ALL patient cells. Moreover, the mechanism of action underlying OSE-127’s anti-leukemic activity remained to be fully elucidated. Here we show that CD127 is expressed by >84% ALL patients and that OSE-127 efficiently targets CD127 not only via its IL7R antagonist activity but also through macrophage-mediated antibody dependent phagocytosis (ADCP). First, CD127 surface expression was prospectively measured by flow cytometry in 372 diagnostic ALL patient samples. We detected CD127-positivity (defined as ≥10% CD127+ blasts) in 84.4% (314/372) cases, of which 39.5% (147/372) were CD127hi (≥ 50% CD127+ blasts). CD127 expression was higher in T- than in B-ALL. Among B-ALL, highest expression was detected in E2A-PBX1+ and BCR-ABL-like ALLs. Mechanistically, OSE-127 blocked STAT5 phosphorylation in IL7-responsive ALL-PDX cells, leading to decreased cell survival and proliferation. Surprisingly, we detected high in vivo efficacy of OSE-127 therapy in IL7-unresponsive PDXs (e.g., unable to induce phosphorylation of STAT5 upon ex vivo IL7 stimulation or with IL7R mutation-induced constitutive phosphorylation of STAT5). We uncovered that OSE-127 induced macrophage-mediated ADCP of CD127+ ALL cells in vitro. Accordingly, treatment of IL7-unresponsive, but OSE-127-sensitive models with an OSE-127-LALAPG variant (conserving IL7R-antagonistic properties but lacking ADCP activity due to Fc-inactivating mutations) did not impact leukemia development, thereby substantiating that ADCP contributes to the anti-leukemic efficacy of OSE-127. In fact, ADCP levels induced by OSE-127 treatment in vitro correlated with its capacity to reduce ALL blasts in the blood of PDX mice in vivo. Altogether, through its dual mode of action, OSE-127 may represent a powerful novel immunotherapy option for ALL patients, including cases with dysregulated IL7R signaling, particularly in combination with standard of care polychemotherapy. Citation Format: Irene Baccelli, Lennart Lenk, Anna Laqua, Dorothee Winterberg, Anna Dietterle, Frederique Corallo, Julien Taurelle, Emma Narbeburu, Beat Bornhauser, Jean-Pierre Bourquin, Fotini Vogiatzi, Simon Raffel, Martin Schrappe, Gunnar Cario, Monika Brüggemann, Denis M Schewe, Nicolas Poirier. CD127 is expressed by acute lymphoblastic leukemias and is efficiently targeted by the IL7R-antagonist OSE-127 through macrophage-mediated antibody dependent phagocytosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2957.

Augmented antibody-based anticancer therapeutics boost neutrophil cytotoxicity.

Most clinically used anticancer mAbs are of the IgG isotype, which can eliminate tumor cells through NK cell-mediated antibody-dependent cellular cytotoxicity and macrophage-mediated antibody-dependent phagocytosis. IgG, however, ineffectively recruits neutrophils as effector cells. IgA mAbs induce migration and activation of neutrophils through the IgA Fc receptor (FcαRI) but are unable to activate NK cells and have poorer half-life. Here, we combined the agonistic activity of IgG mAbs and FcαRI targeting in a therapeutic bispecific antibody format. The resulting TrisomAb molecules recruited NK cells, macrophages, and neutrophils as effector cells for eradication of tumor cells in vitro and in vivo. Moreover, TrisomAb had long in vivo half-life and strongly decreased B16F10gp75 tumor outgrowth in mice. Importantly, neutrophils of colorectal cancer patients effectively eliminated tumor cells in the presence of anti-EGFR TrisomAb but were less efficient in mediating killing in the presence of IgG anti-EGFR mAb (cetuximab). The clinical application of TrisomAb may provide potential alternatives for cancer patients who do not benefit from current IgG mAb therapy.

Single-Arm Phase II Study of MOR208 Combined with Lenalidomide in Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma: L-Mind

Introduction: The CD19 antigen is broadly and homogeneously expressed across different B-cell malignancies, including diffuse large B-cell lymphoma (DLBCL). MOR208 is an Fc-enhanced, humanized, monoclonal antibody that targets CD19, leading to natural killer (NK) cell-mediated antibody-dependent cytotoxicity, macrophage-mediated antibody-dependent phagocytosis and direct cytotoxicity. The immunomodulatory drug, lenalidomide (LEN), has both antiproliferative and antiangiogenic effects, and can stimulate the activity of immune effectors, such as NK cells. MOR208 and LEN have each shown single agent activity in patients with relapsed or refractory (R-R) DLBCL. In addition, MOR208 and LEN have shown synergy in in vitro and in vivo lymphoma models. We present results of an ongoing, multicenter phase II study designed to assess the safety and efficacy of MOR208 combined with LEN in patients with R-R DLBCL (NCT02399085).Methods:Patients >18 years of age diagnosed with DLBCL, an Eastern Cooperative Oncology Group performance status 0-2, and adequate organ function, who had relapsed after or were refractory to at least one but not more than three prior systemic therapies, including at least one CD20-targeting regimen, and who were not candidates for high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT), were eligible. Patients with primary refractory disease (defined as no response to or progression during or within 6 months after completion of frontline therapy for DLBCL) were excluded. Treatment comprises up to twelve 28-day cycles of MOR208, administered intravenously at a dose of 12 mg/kg weekly during cycles 1-3 (plus a loading dose on day 4 of cycle 1), and every second week during cycles 4-12. LEN was administered orally at a daily dose of 25 mg on days 1-21 of each cycle, for up to 12 cycles. Patients who were progression-free after 12 cycles received MOR208 every second week until progression. The primary endpoint is the objective response rate (ORR), centrally assessed, as per the International Working Group criteria 2007, incorporating PET-based imaging. Secondary endpoints include ORR as per investigator assessment, duration of response (DoR), progression-free survival (PFS) and overall survival (OS), safety, and analysis of outcomes by cell of origin and other biomarkers.Results: As of November 2017, 81 patients had been enrolled and recruitment is complete. We report here updated preliminary results with a data cutoff of 5 June 2018. Median age was 72 years (range 41-87); 40 (49%) patients had received ≥2 prior lines of therapy (median 2, range 1-4); 31 (38%) had rituximab refractory disease; 33 (41%) were refractory to the previous line of therapy, 43 (53%) had Ann Arbor stage ≥III disease; and 42 (52%) had an International Prognostic Index of 3-5 at study entry, indicating poor prognosis. The most common treatment-emergent adverse events (any grade/grade ≥3) were neutropenia in 39/35 (48%/43%) patients, thrombocytopenia in 26/14 (32%/17%), anemia in 25/7 (31%/9%), diarrhea in 24/1 (30%/1%), pyrexia in 18/1 (22%/1%) and asthenia in 16/2 (20%/2%) patients. Thirty-four (42%) patients required dose reduction with LEN, 58 (72%) patients overall could stay on a daily LEN dose of 20 mg or higher. Based on investigator assessments, complete and partial responses were observed in 27 (33%) and 20 (25%) patients, respectively, resulting in an ORR of 58%. A further 12 (15%) patients had stable disease. With a median follow-up of 12 months, the median PFS was 16.2 months (95% CI: 6.3-not reached [NR]). Responses were durable with a median DoR not reached (95% CI: NR-NR) and 70% of responding patients were without progression at 12 months (Kaplan-Meier estimate). A significant proportion of patients (37/81; 46%) are still on study treatment, with 19 having been treated for over 12 months. Median OS has not been reached (95% CI: 18.6-NR); the 12-month OS rate was 73% (95% CI: 63-85).Conclusions: MOR208 in combination with LEN has shown highly encouraging activity in patients with R-R DLBCL who were ineligible for HDC and ASCT and who had a poor prognosis. These results indicate a significant improvement in outcome for these patients who have very limited treatment options. MOR208 plus LEN was well tolerated in this population, without evidence of additive toxicity. Treatment and follow-up are currently ongoing, as are cell of origin and other biomarker analyses. DisclosuresSalles:Novartis: Consultancy, Honoraria; Epizyme: Honoraria; Gilead: Honoraria; Janssen: Honoraria; Merck: Honoraria; Morphosys: Honoraria; Pfizer: Honoraria; Servier: Honoraria; Takeda: Honoraria; Amgen: Honoraria; Acerta: Honoraria; AbbVie: Honoraria; Celgene: Honoraria, Research Funding; Roche: Honoraria, Research Funding. González-Barca:Roche: Speakers Bureau; Celtrion: Consultancy; Gilead: Consultancy; janssen: Consultancy, Speakers Bureau. Jurczak:Pharmacyclics: Research Funding; MorphoSys: Research Funding; Merck: Research Funding; Nordic Nanovector: Research Funding; Janssen: Research Funding; Epizyme: Research Funding; Celgene: Research Funding; Beigene: Research Funding; Bayer: Research Funding; Afimed: Research Funding; Sandoz-Novartis: Consultancy; Janssen: Consultancy; European Medicines Agency: Consultancy; AstraZeneca: Consultancy; Acerta: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Servier: Research Funding; Roche: Research Funding; TG Therapeutics: Research Funding. Gaidano:Morphosys: Honoraria; AbbVie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Kalakonda:Celgene: Research Funding. Dreyling:Bayer: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Acerta: Consultancy; Roche: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Sandoz: Consultancy. Zinzani:Janssen: Honoraria, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Honoraria, Speakers Bureau; SERVIER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees. Dirnberger-Hertweck:MorphoSys: Employment. Weirather:MorphoSys: Employment. Ambarkhane:MorphoSys: Employment. Maddocks:Pharmacyclics: Research Funding; Novartis: Research Funding; Pharmacyclics/Janssen: Honoraria; AstraZeneca: Honoraria; Teva: Honoraria; Merck: Research Funding; BMS: Research Funding.