RESUMEN
We have conjugated the murine monoclonal anti-CD19 antibody B43 to the tyrosine kinase inhibitor genistein to construct an effective immunoconjugate against CD19 antigen positive hematologic malignancies. The scaled-up production and purification of B43 antibody, genistein, and B43-Genistein immunoconjugate permitted the manufacturing of a highly purified clinical-grade B43-Genistein preparation. In clonogenic assays, B43-Genistein elicited selective and potent cytotoxicity against CD19 antigen positive human leukemia cells. To our knowledge, this work represents the first effort of producing a clinical-grade genistein immunoconjugate for treatment of B-lineage leukemia and lymphoma.
Asunto(s)
Anticuerpos Monoclonales , Antineoplásicos , Genisteína , Inmunoconjugados/química , Antineoplásicos/uso terapéutico , Genisteína/uso terapéutico , Humanos , Inmunoconjugados/uso terapéutico , Leucemia/terapia , Linfoma/terapia , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
We have conjugated the murine monoclonal anti-CD7 antibody TXU to the plant hemitoxin pokeweed antiviral protein (PAP) to construct an effective immunotoxin against CD7 antigen positive hematologic malignancies. The scaled-up production and purification of TXU antibody, PAP toxin, and TXU-PAP immunotoxin permitted the manufacturing of a highly purified clinical-grade TXU-PAP preparation. In clonogenic assays, TXU-PAP elicited selective and potent cytotoxicity against CD7 antigen positive human leukemia cells and killed primary clonogenic leukemic cells from T-lineage acute lymphoblastic leukemia (ALL) patients. To our knowledge, this pre-IND work represents the first effort of producing a clinical-grade PAP immunotoxin for treatment of T-lineage ALL. Since the CD7 antigen is also expressed on AML cells, TXU-PAP could also be useful for the treatment of CD7 positive acute myeloid leukemia (AML) patients.
Asunto(s)
Antígenos CD7/inmunología , Antineoplásicos Fitogénicos/uso terapéutico , Inmunotoxinas/uso terapéutico , Leucemia-Linfoma de Células T del Adulto/tratamiento farmacológico , N-Glicosil Hidrolasas , Proteínas de Plantas/inmunología , Anticuerpos Monoclonales , Ensayos Clínicos como Asunto , Humanos , Inmunotoxinas/aislamiento & purificación , Control de Calidad , Proteínas Inactivadoras de Ribosomas Tipo 1RESUMEN
The investigational biotherapeutic agent, B43(anti-CD19)-pokeweed antiviral protein (PAP) immunotoxin, has shown substantial anti-leukemic activity in SCID mouse models of human B-lineage leukemia and lymphoma. In this report, we describe the results of a comprehensive preclinical toxicity study which determined the toxicity profile of B43-PAP in BALB/c mice. Administration of unconjugated B43 monoclonal antibody was not associated with any toxicity, whereas B43-PAP caused dose-limiting and cardiac and renal toxicities which were fatal. In addition, B43-PAP also caused multifocal skeletal myofiber necrosis, which was associated with abnormal gait and lethargy. Notably, parenteral administrations of methylprednisolone, pentoxyphylline, or dopamine were able to markedly reduce B43-PAP related toxicity. This study provides a basis for further evaluation of the toxicity of B43-PAP in monkeys and humans.
