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Phase 1 Dose-Escalation Study of Pegylated Arginine Deiminase, Cisplatin, and Pemetrexed in Patients With Argininosuccinate Synthetase 1-Deficient Thoracic Cancers

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Spicer, J 
Chan, PY 
Khadeir, R 
Corbacho, JG 



Pegylated arginine deiminase (ADI-PEG 20) depletes essential amino acid levels in argininosuccinate synthetase 1 (ASS1) –negative tumors by converting arginine to citrulline and ammonia. The main aim of this study was to determine the recommended dose, safety, and tolerability of ADI-PEG 20, cisplatin, and pemetrexed in patients with ASS1-deficient malignant pleural mesothelioma (MPM) or non–small-cell lung cancer (NSCLC).

Patients and Methods

Using a 3 + 3 + 3 dose-escalation study, nine chemotherapy-naïve patients (five MPM, four NSCLC) received weekly ADI-PEG 20 doses of 18 mg/m2, 27 mg/m2, or 36 mg/m2, together with pemetrexed 500 mg/m2 and cisplatin 75 mg/m2 which were given every three weeks (maximum of six cycles). Patients achieving stable disease or better could continue ADI-PEG 20 monotherapy until disease progression or withdrawal. Adverse events were assessed by Common Terminology Criteria for Adverse Events version 4.03, and pharmacodynamics and immunogenicity were also evaluated. Tumor response was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 for NSCLC and by modified RECIST criteria for MPM.


No dose-limiting toxicities were reported; nine of 38 reported adverse events (all grade 1 or 2) were related to ADI-PEG 20. Circulating arginine concentrations declined rapidly, and citrulline levels increased; both changes persisted at 18 weeks. Partial responses were observed in seven of nine patients (78%), including three with either sarcomatoid or biphasic MPM.


Target engagement with depletion of arginine was maintained throughout treatment with no dose-limiting toxicities. In this biomarker-selected group of patients with ASS1-deficient cancers, clinical activity was observed in patients with poor-prognosis tumors. Therefore, we recommend a dose for future studies of weekly ADI-PEG 20 36 mg/m2 plus three-weekly cisplatin 75 mg/m2 and pemetrexed 500 mg/m2.



Aged, Antineoplastic Combined Chemotherapy Protocols, Argininosuccinate Synthase, Carcinoma, Non-Small-Cell Lung, Cisplatin, Dose-Response Relationship, Drug, Female, Humans, Hydrolases, Lung Neoplasms, Male, Mesothelioma, Mesothelioma, Malignant, Middle Aged, Pemetrexed, Pleural Neoplasms, Polyethylene Glycols

Journal Title

Journal of Clinical Oncology

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American Society of Clinical Oncology
Cancer Research UK (C37096/A16673)
We thank the Department of Health, England, for financial support via the National Institute for Health Research (NIHR) Biomedical Research Centre, and Guy’s and St Thomas’ NHS Foundation Trust in partnership with King’s College London and the King’s College Hospital NHS Foundation Trust (and NIHR Clinical Research Facility). Barts, Cambridge, and King’s College London are Experimental Cancer Medicine Centers supported by Cancer Research UK and the Department of Health, England. Patients were treated using the facilities provided by the Welcome Trust, Addenbrookes Centre for Clinical Investigations.