Fibroblasts Activation Protein (FAP) is a type 2 transmembrane serine protease overexpressed by cancer-associated fibroblasts (CAFs). CAFs are predominant stromal cells within the tumor microenvironment involved in numerous activities promoting its development. In particular, the overexpression of FAP occurs in 90% of epithelial carcinomas, while in healthy adult tissues the expression is very low if not absent. For this reason, the FAP enzyme represents a new and interesting teragnostic target in the oncology field. In recent years, several molecules have been developed that are able to specifically bind the enzyme; among these, quinolinic-based inhibitors of the fibroblast activating protein have been synthesized, called FAPI, which are bound to 68Ga or 177Lu radionuclides respectively for use in diagnostics and in radiometabolic therapy. The purpose of this work was the study of the manual labeling process of the radiopharmaceutical 68Ga-FAPI-46 and the implementation of the method for carrying out quality controls. Methods: the synthesis of 68Ga-FAPI-46 was carried out by mixing 50 µg of precursor FAPI-46 in a suitable buffer with a 68GaCl3 solution obtained by elution from a pharmaceutical grade 68Ge / 68Ga generator. After incubation at a controlled temperature, the reaction mixture was analyzed for all purity parameters required by the European Pharmacopoeia (visual appearance, pH, RCP, RNP, stability, sterility and apyrogenicity). Results: a reproducible manual labeling method was developed which allows to obtain the radiopharmaceutical 68Ga-FAPI-46 suitable for administration to the patient with high purity (> 95%) and stable in vitro for the time of use. Conclusions: the present work allowed to validate the labeling and quality control processes of the experimental radiopharmaceutical 68Ga-FAPI-46 that will be used for a clinical protocol.
Fibroblasts Activation Protein (FAP) è una serin proteasi transmembrana di tipo 2 sovraespressa dai fibroblasti associati al cancro (CAFs), cellule stromali predominanti all’interno del microambiente tumorale coinvolte in numerose attività promotrici del suo sviluppo. In particolare, la sovraespressione di FAP si presenta nel 90% dei carcinomi epiteliali, mentre nei tessuti adulti sani l’espressione è molto bassa se non assente. Per questa ragione, l’enzima FAP rappresenta un nuovo e interessante target teragnostico in ambito oncologico. Negli ultimi anni sono stati sviluppati diverse molecole in grado di legare in modo specifico l’enzima; tra queste, sono stati sintetizzati degli inibitori a base chinolinica della proteina attivante i fibroblasti che prendono il nome di FAPI, i quali vengono legati ai radionuclidi 68Ga o 177Lu rispettivamente per l’utilizzo in diagnostica e in terapia radiometabolica. Lo scopo di questo lavoro è stato lo studio del processo di marcatura manuale del radiofarmaco 68Ga-FAPI-46 e l’implementazione della metodica per l’esecuzione dei controlli di qualità. Metodi: la sintesi del 68Ga-FAPI-46 è stata effettuata miscelando 50 µg di precursore FAPI-46 in opportuno tampone con una soluzione di 68GaCl3 ottenuta per eluizione da un generatore 68Ge/68Ga di grado farmaceutico. Dopo incubazione a temperatura controllata, la miscela di reazione è stata analizzata per tutti i parametri di purezza previsti dalla Farmacopea Europea (aspetto visivo, pH, RCP, RNP, stabilità, sterilità e apirogenicità). Risultati: è stata sviluppata una metodica di marcatura manuale riproducibile che consente di ottenere il radiofarmaco 68Ga-FAPI-46 idoneo per la somministrazione al paziente con elevata purezza (>95%) e stabile in vitro per il tempo di utilizzo. Conclusioni: il presente lavoro ha permesso di convalidare i processi di marcatura e controllo qualità del radiofarmaco sperimentale 68Ga-FAPI-46 che verrà utilizzato per un protocollo clinico.
Il nuovo radiofarmaco sperimentale 68Ga-FAPI-46: convalida del processo di sintesi e controllo qualità presso la Radiofarmacia dell’Istituto Europeo di Oncologia
VALSESIA, FEDERICA
2021/2022
Abstract
Fibroblasts Activation Protein (FAP) is a type 2 transmembrane serine protease overexpressed by cancer-associated fibroblasts (CAFs). CAFs are predominant stromal cells within the tumor microenvironment involved in numerous activities promoting its development. In particular, the overexpression of FAP occurs in 90% of epithelial carcinomas, while in healthy adult tissues the expression is very low if not absent. For this reason, the FAP enzyme represents a new and interesting teragnostic target in the oncology field. In recent years, several molecules have been developed that are able to specifically bind the enzyme; among these, quinolinic-based inhibitors of the fibroblast activating protein have been synthesized, called FAPI, which are bound to 68Ga or 177Lu radionuclides respectively for use in diagnostics and in radiometabolic therapy. The purpose of this work was the study of the manual labeling process of the radiopharmaceutical 68Ga-FAPI-46 and the implementation of the method for carrying out quality controls. Methods: the synthesis of 68Ga-FAPI-46 was carried out by mixing 50 µg of precursor FAPI-46 in a suitable buffer with a 68GaCl3 solution obtained by elution from a pharmaceutical grade 68Ge / 68Ga generator. After incubation at a controlled temperature, the reaction mixture was analyzed for all purity parameters required by the European Pharmacopoeia (visual appearance, pH, RCP, RNP, stability, sterility and apyrogenicity). Results: a reproducible manual labeling method was developed which allows to obtain the radiopharmaceutical 68Ga-FAPI-46 suitable for administration to the patient with high purity (> 95%) and stable in vitro for the time of use. Conclusions: the present work allowed to validate the labeling and quality control processes of the experimental radiopharmaceutical 68Ga-FAPI-46 that will be used for a clinical protocol.È consentito all'utente scaricare e condividere i documenti disponibili a testo pieno in UNITESI UNIPV nel rispetto della licenza Creative Commons del tipo CC BY NC ND.
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https://hdl.handle.net/20.500.14239/14609