Lenzilumab (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

; development code KB003) is a

humanized monoclonal antibody Humanized antibodies are antibodies from non-human species whose protein sequences have been modified to increase their similarity to antibody variants produced naturally in humans. The process of "humanization" is usually applied to monoclonal an ...

(class IgG1 kappa) that targets colony stimulating factor 2 (CSF2)/granulocyte-macrophage colony stimulating factor (

GM-CSF Granulocyte-macrophage colony-stimulating factor (GM-CSF), also known as colony-stimulating factor 2 (CSF2), is a monomeric glycoprotein secreted by macrophages, T cells, mast cells, natural killer cells, endothelial cells and fibroblasts that ...

). Pre-clinical evidence and clinical data implicate GM-CSF as a crucial initiator in the systemic inflammatory pathway driving the serious and life-threatening

chimeric antigen receptor T cell In biology, chimeric antigen receptors (CARs)—also known as chimeric immunoreceptors, chimeric T cell receptors or artificial T cell receptors—are receptor proteins that have been engineered to give T cells the new ability to target a specifi ...

(CAR-T) associated

cytokine release syndrome Cytokine release syndrome (CRS) is a form of systemic inflammatory response syndrome (SIRS) that can be triggered by a variety of factors such as infections and certain drugs. It refers to cytokine storm syndromes (CSS) and occurs when large numb ...

(CRS). GM-CSF is produced by CAR-T cells upon recognition of target cells, which activates myeloid cells and compels them to produce monocyte chemoattractant protein 1 (MCP-1) and its receptor (CCR2). GM-CSF knockout CAR-T cells protect mice from CRS; however, IL-6 knockout mice receiving wild-type CAR-T cells were not protected from CRS. Moreover, mice infused with GM-CSF knockout CAR-T cells have significantly lower serum levels of MCP-1, IL-6, MIG, and MIP-1 than mice receiving wild-type CAR-T cells, demonstrating the role of GM-CSF signaling early in the inflammatory cascade. Administration of Lenzilumab in a patient-derived xenograft model significantly reduced CRS and neurotoxicity in mice, while preserving anti-leukemic efficacy. A multi-center phase I/II trial including the

MD Anderson Cancer Center The University of Texas MD Anderson Cancer Center (colloquially MD Anderson Cancer Center) is a comprehensive cancer center in Houston, Texas. It is the largest cancer center in the U.S. and one of the original three comprehensive cancer centers ...

will evaluate lenzilumab as prophylaxis for CRS and neurotoxicity in collaboration with Kite and is currently in recruitment. Additionally, GM-CSF has been shown to be instrumental in donor T-cell licensing of host and donor-derived myeloid cells in

graft versus host disease Graft-versus-host disease (GvHD) is a syndrome, characterized by inflammation in different organs. GvHD is commonly associated with bone marrow transplants and stem cell transplants. White blood cells of the donor's immune system which remain wit ...

(GVHD) following hematopoietic allotransplantation. Mice receiving allografts deficient in GM-CSF have significantly reduced incidence and severity of GVHD. A Phase II study with the University of Zürich and the United Kingdom's Stem Cell Transplantation IMPACT group will be investigating the efficacy of lenzilumab in prevention of acute GVHD and is currently in active planning. In light of the recent

coronavirus disease 2019 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quickly ...

(COVID-19) pandemic, the role of GM-CSF in the cytokine-mediated immunopathology of lung injury and

acute respiratory distress syndrome Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath (dyspnea), rapid breathing (tachypnea), and bluish skin colo ...

(ARDS) has been under investigation. Plasma of hospitalized patients with confirmed COVID-19 has elevated levels of several inflammatory cytokines including IL-1B, IL-2, GM-CSF, IFN-γ, IP-10, MCP-1, MIP-1A/B, TNFα, and VEGF, indicative of a cytokine storm. Importantly, significantly higher levels of MCP-1, MIP-1A, and IP-10 (all of which are downstream of GM-CSF) were found to be significantly higher in ICU-admitted patients versus hospitalized but non-ICU admitted patients. A Phase III protocol for evaluating the efficacy of lenzilumab in the prevention and treatment of ARDS has been submitted to the FDA. Lenzilumab is under development by Humanigen Inc. and was originally designed for the treatment of

chronic myelomonocytic leukemia Chronic myelomonocytic leukemia (CMML) is a type of leukemia, which are cancers of the blood-forming cells of the bone marrow. In adults, blood cells are formed in the bone marrow, by a process that is known as haematopoiesis. In CMML, there are in ...

(CMML) and juvenile myelomonocytic leukemia (JMML).

In vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

studies on human cells have demonstrated that Lenzilumab can induce sensitivity in

myeloid Myeloid tissue, in the bone marrow sense of the word '' myeloid'' ('' myelo-'' + ''-oid''), is tissue of bone marrow, of bone marrow cell lineage, or resembling bone marrow, and myelogenous tissue (''myelo-'' + '' -genous'') is any tissue of, ...

and monocytic cells suggesting the antibody's applicability in CMML and JMML indications. As of 2017, lenzilumab is currently undergoing clinical trials for CMML. Prior to application in treating CMML, lenzilumab was assessed for use in treating inadequately controlled

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

and

rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...

Covid-19

The NIH has chosen lenzilumab for its ACTIV-5 Big Effect trial.

References

{{monoclonals for immune system Monoclonal antibodies