RESUMO
The Fourth Expert Meeting of the Mesenchymal Stem Cells in Solid Organ Transplantation (MiSOT) Consortium took place in Barcelona on October 19 and 20, 2012. This meeting focused on the translation of preclinical data into early clinical settings. This position paper highlights the main topics explored on the safety and efficacy of mesenchymal stem cells as a therapeutic agent in solid organ transplantation and emphasizes the issues (proper timing, concomitant immunossupression, source and immunogenicity of mesenchymal stem cells, and oncogenicity) that have been addressed and will be followed up by the MiSOT Consortium in future studies.
Assuntos
Transplante de Células-Tronco Mesenquimais , Ensaios Clínicos como Assunto , Humanos , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Transplante de Células-Tronco Mesenquimais/legislação & jurisprudênciaRESUMO
BACKGROUND: Cellular therapy after organ transplantation is emerging as an intriguing strategy to achieve dose reduction of classical immunosuppressive pharmacotherapy. Here, we introduce a new scoring system to assess treatment-emergent adverse events (TEAEs) of adherent stem cell therapies in the clinical setting of allogeneic liver transplantation (for example, the MiSOT-I trial Eudract CT: 2009-017795-25). METHODS: The score consists of three independent modalities (set of parameters) that focus on clinically relevant events early after intravenous or intraportal stem cell infusion: pulmonary toxicity, intraportal-infusional toxicity and systemic toxicity. For each modality, values between 0 (no TEAE) and 3 (severe TEAE) were defined. The score was validated retrospectively on a cohort of n=187 recipients of liver allografts not receiving investigational cell therapy between July 2004 and December 2010. These patients represent a control population for further trials. Score values were calculated for days 1, 4, and 10 after liver transplantation. RESULTS: Grade 3 events were most commonly related to the pulmonary system (3.5% of study cohort on day 4). Almost no systemic-related TEAEs were observed during the study period. The relative frequency of grade 3 events never exceeded 5% over all modalities and time points. A subgroup analysis for grade 3 patients provided no descriptors associated with severe TEAEs. CONCLUSION: The MiSOT-I score provides an assessment tool to score specific adverse events that may occur after adherent stem cell therapy in the clinical setting of organ transplantation and is thus a helpful tool to conduct a safety study.
Assuntos
Técnicas de Apoio para a Decisão , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias/etiologia , Transplante de Células-Tronco/efeitos adversos , Adulto , Distribuição de Qui-Quadrado , Intervalo Livre de Doença , Feminino , Rejeição de Enxerto/etiologia , Humanos , Imunossupressores/efeitos adversos , Estimativa de Kaplan-Meier , Transplante de Fígado/imunologia , Transplante de Fígado/mortalidade , Pneumopatias/etiologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/imunologia , Complicações Pós-Operatórias/mortalidade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Transplante de Células-Tronco/mortalidade , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Liver transplantation is the definitive treatment for many end-stage liver diseases. However, the life-long immunosuppression needed to prevent graft rejection causes clinically significant side effects. Cellular immunomodulatory therapies may allow the dose of immunosuppressive drugs to be reduced. In the current protocol, we propose to complement immunosuppressive pharmacotherapy with third-party multipotent adult progenitor cells (MAPCs), a culture-selected population of adult adherent stem cells derived from bone marrow that has been shown to display potent immunomodulatory and regenerative properties. In animal models, MAPCs reduce the need for pharmacological immunosuppression after experimental solid organ transplantation and regenerate damaged organs. METHODS: Patients enrolled in this phase I, single-arm, single-center safety and feasibility study (n = 3-24) will receive 2 doses of third-party MAPCs after liver transplantation, on days 1 and 3, in addition to a calcineurin-inhibitor-free "bottom-up" immunosuppressive regimen with basiliximab, mycophenolic acid, and steroids. The study objective is to evaluate the safety and clinical feasibility of MAPC administration in this patient cohort. The primary endpoint of the study is safety, assessed by standardized dose-limiting toxicity events. One secondary endpoint is the time until first biopsy-proven acute rejection, in order to collect first evidence of efficacy. Dose escalation (150, 300, 450, and 600 million MAPCs) will be done according to a 3 + 3 classical escalation design (4 groups of 3-6 patients each). DISCUSSION: If MAPCs are safe for patients undergoing liver transplantation in this study, a phase II/III trial will be conducted to assess their clinical efficacy.