Overcoming resistance to arginine deprivation therapy using GC7 in pleural mesothelioma.

Pleural mesothelioma is a highly chemotherapy-resistant cancer. Approximately 50% of mesotheliomas do not express argininosuccinate synthetase 1 (ASS1), the rate-limiting enzyme in arginine biosynthesis, making arginine depletion with pegylated arginine deiminase (ADI-PEG20) an attractive therapeutic strategy. We investigated whether combinatory treatment composed of ADI-PEG20 and polyamine inhibitors constitutes a promising novel therapeutic strategy to overcome ADI-PEG20 resistance in mesothelioma patients.

Arginine deprivation/citrulline augmentation with ADI-PEG20 as novel therapy for complications in type 2 diabetes.

Objective: Chronic inflammation and oxidative stress mediate the pathological progression of diabetic complications, like diabetic retinopathy (DR), peripheral neuropathy (DPN) and impaired wound healing. Studies have shown that treatment with a stable form of arginase 1 that reduces l-arginine levels and increases ornithine and urea limits retinal injury and improves visual function in DR. We tested the therapeutic efficacy of PEGylated arginine deiminase (ADI-PEG20) that depletes l-arginine and elevates l-citrulline on diabetic complications in the db/db mouse model of type 2 diabetes (T2D).

Pegargiminase Plus First-Line Chemotherapy in Patients With Nonepithelioid Pleural Mesothelioma: The ATOMIC-Meso Randomized Clinical Trial.

Importance: Arginine deprivation using ADI-PEG20 (pegargiminase) combined with chemotherapy is untested in a randomized study among patients with cancer. ATOMIC-Meso (ADI-PEG20 Targeting of Malignancies Induces Cytotoxicity-Mesothelioma) is a pivotal trial comparing standard first-line chemotherapy plus pegargiminase or placebo in patients with nonepithelioid pleural mesothelioma.

Objective: To determine the effect of pegargiminase-based chemotherapy on survival in nonepithelioid pleural mesothelioma, an arginine-auxotrophic tumor.

A role for macrophages under cytokine control in mediating resistance to ADI-PEG20 (pegargiminase) in ASS1-deficient mesothelioma.

Background: Pegylated arginine deiminase (ADI-PEG20; pegargiminase) depletes arginine and improves survival outcomes for patients with argininosuccinate synthetase 1 (ASS1)-deficient malignant pleural mesothelioma (MPM). Optimisation of ADI-PEG20-based therapy will require a deeper understanding of resistance mechanisms, including those mediated by the tumor microenvironment. Here, we sought to reverse translate increased tumoral macrophage infiltration in patients with ASS1-deficient MPM relapsing on pegargiminase therapy.

Role of 3'-Deoxy-3'-[F] Fluorothymidine Positron Emission Tomography-Computed Tomography as a Predictive Biomarker in Argininosuccinate Synthetase 1-Deficient Thoracic Cancers Treated With Pegargiminase.

Introduction: Pegargiminase (ADI-PEG 20I) degrades arginine in patients with argininosuccinate synthetase 1-deficient malignant pleural mesothelioma (MPM) and NSCLC. Imaging with proliferation biomarker 3'-deoxy-3'-[F] fluorothymidine (F-FLT) positron emission tomography (PET)-computed tomography (CT) was performed in a phase 1 study of pegargiminase with pemetrexed and cisplatin (ADIPemCis). The aim was to determine whether FLT PET-CT predicts treatment response earlier than CT.

Pilot Trial of Arginine Deprivation Plus Nivolumab and Ipilimumab in Patients with Metastatic Uveal Melanoma.

Metastatic uveal melanoma (UM) remains challenging to treat, with objective response rates to immune checkpoint blockade (ICB) being much lower than in primary cutaneous melanoma (CM). Besides a lower mutational burden, the overall immune-excluded tumor microenvironment of UM might contribute to the poor response rate. We therefore aimed at targeting deficiency in argininosuccinate synthase 1, which is a key metabolic feature of UM.

A Phase 1 study of ADI-PEG20 (pegargiminase) combined with cisplatin and pemetrexed in ASS1-negative metastatic uveal melanoma.

Metastatic uveal melanoma (UM) is a devastating disease with few treatment options. We evaluated the safety, tolerability and preliminary activity of arginine depletion using pegylated arginine deiminase (ADI-PEG20; pegargiminase) combined with pemetrexed (Pem) and cisplatin (Cis) chemotherapy in a phase 1 dose-expansion study of patients with argininosuccinate synthetase (ASS1)-deficient metastatic UM. Eligible patients received up to six cycles of Pem (500 mg/m ) and Cis (75 mg/m ) every 3 weeks plus weekly intramuscular ADI (36 mg/m ), followed by maintenance ADI until progression (NCT02029690).

Arginine deprivation alters microglial polarity and synergizes with radiation to eradicate non-arginine-auxotrophic glioblastoma tumors.

New approaches for the management of glioblastoma (GBM) are an urgent and unmet clinical need. Here, we illustrate that the efficacy of radiotherapy for GBM is strikingly potentiated by concomitant therapy with the arginine-depleting agent ADI-PEG20 in a non-arginine-auxotrophic cellular background (argininosuccinate synthetase 1 positive). Moreover, this combination led to durable and complete radiological and pathological response, with extended disease-free survival in an orthotopic immune-competent model of GBM, with no significant toxicity.

Pegylated arginine deiminase drives arginine turnover and systemic autophagy to dictate energy metabolism.

Obesity is a multi-systemic disorder of energy balance. Despite intense investigation, the determinants of energy homeostasis remain incompletely understood, and efficacious treatments against obesity and its complications are lacking. Here, we demonstrate that conferred arginine iminohydrolysis by the bacterial virulence factor and arginine deiminase, , promotes mammalian energy expenditure and insulin sensitivity and reverses dyslipidemia, hepatic steatosis, and inflammation in obese mice.

Expansion Phase 1 Study of Pegargiminase Plus Pemetrexed and Cisplatin in Patients With Argininosuccinate Synthetase 1-Deficient Mesothelioma: Safety, Efficacy, and Resistance Mechanisms.

Introduction: Pegargiminase (ADI-PEG 20; ADI) degrades arginine and potentiates pemetrexed (Pem) cytotoxicity in argininosuccinate synthetase 1 (ASS1)-deficient malignant pleural mesothelioma (MPM). We conducted a phase 1 dose-expansion study at the recommended phase 2 dose of ADI-PEG 20 with Pem and cisplatin (ADIPemCis), to further evaluate arginine-lowering therapy in ASS1-deficient MPM and explore the mechanisms of resistance.

Methods: A total of 32 patients with ASS1-deficient MPM (11 epithelioid; 10 biphasic;11 sarcomatoid) who were chemonaive received weekly intramuscular pegargiminase (36 mg/m) with Pem (500 mg/m) and cisplatin (75 mg/m) intravenously, every 3 weeks (six cycles maximum).

Assessment of pegylated arginine deiminase and modified FOLFOX6 in patients with advanced hepatocellular carcinoma: Results of an international, single-arm, phase 2 study.

Background: Arginine starvation depletes the micronutrients required for DNA synthesis and interferes with both thymidylate synthetase activity and DNA repair pathways in preclinical models of hepatocellular carcinoma (HCC). Pegylated arginine deiminase (ADI-PEG 20), an arginine degrader, potentiates the cytotoxic activity of platinum and pyrimidine antimetabolites in HCC cellular and murine models.

Methods: This was a global, multicenter, open-label, single-arm, phase 2 trial of ADI-PEG 20 and modified 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) in patients who had HCC with Child-Pugh A cirrhosis and disease progression on ≥2 prior lines of treatment.

Phase 1, pharmacogenomic, dose-expansion study of pegargiminase plus pemetrexed and cisplatin in patients with ASS1-deficient non-squamous non-small cell lung cancer.

Introduction: We evaluated the arginine-depleting enzyme pegargiminase (ADI-PEG20; ADI) with pemetrexed (Pem) and cisplatin (Cis) (ADIPemCis) in ASS1-deficient non-squamous non-small cell lung cancer (NSCLC) via a phase 1 dose-expansion trial with exploratory biomarker analysis.

Methods: Sixty-seven chemonaïve patients with advanced non-squamous NSCLC were screened, enrolling 21 ASS1-deficient subjects from March 2015 to July 2017 onto weekly pegargiminase (36 mg/m ) with Pem (500 mg/m ) and Cis (75 mg/m ), every 3 weeks (four cycles maximum), with maintenance Pem or pegargiminase. Safety, pharmacodynamics, immunogenicity, and efficacy were determined; molecular biomarkers were annotated by next-generation sequencing and PD-L1 immunohistochemistry.

Phase 1b study of pegylated arginine deiminase (ADI-PEG 20) plus Pembrolizumab in advanced solid cancers.

Background: Pegylated arginine deiminase (ADI-PEG 20) is a metabolism-based strategy that depletes arginine, resulting in tumoral stress and cytotoxicity. Preclinically, ADI-PEG 20 modulates T-cell activity and enhances the therapeutic efficacy of programmed death-1 (PD-1) inhibition.

Methods: A phase 1b study, including a dose-escalation cohort and an expansion cohort, was undertaken to explore the effects of ADI-PEG 20 in combination with pembrolizumab, an anti-PD-1 antibody, for safety, pharmacodynamics, and response.

Phase I study of ADI-PEG20 plus low-dose cytarabine for the treatment of acute myeloid leukemia.

Most acute myeloid leukemia (AML) cells are argininosuccinate synthetase-deficient. Pegylated arginine deiminase (ADI-PEG20) monotherapy depletes circulating arginine, thereby selectively inducing tumor cell death. ADI-PEG20 was shown to induce complete responses in ~10% of relapsed/refractory or poor-risk AML patients.

Phase 1 trial of ADI-PEG20 plus cisplatin in patients with pretreated metastatic melanoma or other advanced solid malignancies.

Background: Arginine depletion interferes with pyrimidine metabolism and DNA damage-repair pathways, and pairing arginine deiminase pegylated with 20,000-molecular-weight polyethylene glycol (ADI-PEG20) with platinum enhances cytotoxicity in vitro and in vivo in arginine auxotrophs.

Methods: This single-centre, Phase 1 trial was conducted using a 3 + 3 dose escalation designed to assess safety, tolerability and determine the recommended Phase 2 dose (RP2D) of ADI-PEG20.

Results: We enrolled 99 patients with metastatic argininosuccinate synthetase 1 (ASS1) deficient malignancies.

Phase II Study of Arginine Deprivation Therapy With Pegargiminase in Patients With Relapsed Sensitive or Refractory Small-cell Lung Cancer.

Background: Pre-clinical studies indicated that arginine-deprivation therapy using pegylated arginine deiminase (pegargiminase, ADI-PEG 20) may be effective in patients with argininosuccinate synthetase 1 (ASS1)-deficient small-cell lung cancer (SCLC).

Patients And Methods: Patients were enrolled into either a 'sensitive' disease cohort (≥ 90 days response to first-line chemotherapy) or a 'refractory' disease cohort (progression while on chemotherapy or < 90 days afterwards or ≥ third-line treatment). Patients received weekly intramuscular pegargiminase, 320 IU/m (36.

Exploiting Arginine Auxotrophy with Pegylated Arginine Deiminase (ADI-PEG20) to Sensitize Pancreatic Cancer to Radiotherapy via Metabolic Dysregulation.

Distinct metabolic vulnerabilities of cancer cells compared with normal cells can potentially be exploited for therapeutic targeting. Deficiency of argininosuccinate synthetase-1 (ASS1) in pancreatic cancers creates auxotrophy for the semiessential amino acid arginine. We explored the therapeutic potential of depleting exogenous arginine via pegylated arginine deiminase (ADI-PEG20) treatment as an adjunct to radiotherapy.

MYC-Driven Small-Cell Lung Cancer is Metabolically Distinct and Vulnerable to Arginine Depletion.

Purpose: Small-cell lung cancer (SCLC) has been treated clinically as a homogeneous disease, but recent discoveries suggest that SCLC is heterogeneous. Whether metabolic differences exist among SCLC subtypes is largely unexplored. In this study, we aimed to determine whether metabolic vulnerabilities exist between SCLC subtypes that can be therapeutically exploited.

A Phase I Study of Pegylated Arginine Deiminase (Pegargiminase), Cisplatin, and Pemetrexed in Argininosuccinate Synthetase 1-Deficient Recurrent High-grade Glioma.

Purpose: Patients with recurrent high-grade gliomas (HGG) are usually managed with alkylating chemotherapy ± bevacizumab. However, prognosis remains very poor. Preclinically, we showed that HGGs are a target for arginine depletion with pegargiminase (ADI-PEG20) due to epimutations of argininosuccinate synthetase () and/or argininosuccinate lyase ().

Efficacy of arginine depletion by ADI-PEG20 in an intracranial model of GBM.

Glioblastoma multiforme (GBM) remains a cancer with a poor prognosis and few effective therapeutic options. Successful medical management of GBM is limited by the restricted access of drugs to the central nervous system (CNS) caused by the blood brain barrier (BBB). We previously showed that a subset of GBM are arginine auxotrophic because of transcriptional silencing of ASS1 and/or ASL and are sensitive to pegylated arginine deiminase (ADI-PEG20).

A phase 1 study of ADI-PEG 20 and modified FOLFOX6 in patients with advanced hepatocellular carcinoma and other gastrointestinal malignancies.

Purpose: Arginine depletion interferes with pyrimidine metabolism as well as DNA damage repair pathways. Preclinical data indicates that pairing pegylated arginine deiminase (ADI-PEG 20) with fluoropyrimidines or platinum enhances cytotoxicity in vitro and in vivo in arginine auxotrophs.

Methods: This is a single-center, open-label, phase 1 trial of ADI-PEG 20 and modified FOLFOX6 (mFOLFOX6) in treatment-refractory hepatocellular carcinoma (HCC) and other advanced gastrointestinal tumors.

Argininosuccinate Synthetase-1 (ASS1) Loss in High-Grade Neuroendocrine Carcinomas of the Urinary Bladder: Implications for Targeted Therapy with ADI-PEG 20.

High-grade neuroendocrine carcinomas (HGNECs) of the urinary bladder encompass small cell (SCNEC) and large cell neuroendocrine carcinomas (LCNEC). Currently, recommended initial management is with systemic chemotherapy, followed by consolidative therapy with either radical cystectomy or radiotherapy in patients with localized disease. Nevertheless, survival in this setting remains poor.