Targeting Acute Myelogenous Leukemia Using Potent Human Dihydroorotate Dehydrogenase Inhibitors Based on the 2-Hydroxypyrazolo[1,5-a]pyridine Scaffold: SAR of the Biphenyl Moiety.

Stefano Sainas,Alice Passoni,Giuseppe Saglio,Paola Circosta,Salam Al-Karadaghi,Mariia Mishina,Barbara Canepa,Alessandro Bona,Cristina Ramondetti,Marco Piccinini,Donatella Boschi,Mohammad Houshmand,Enrico Giraudo,Renzo Bagnati,Alessandro Cignetti,Davide Bonanni,Carina Florina Cojocaru,Barbara Buccinnà,Valentina Gaidano,Marta Giorgis,Barbara Rolando,Agnese Chiara Pippione ,Yueming Qiu ,Marco Lucio Lolli

doi:10.1021/acs.jmedchem.0c01549

Abstract

The connection with acute myelogenous leukemia (AML) of dihydroorotate dehydrogenase (hDHODH), a key enzyme in pyrimidine biosynthesis, has attracted significant interest from pharma as a possible AML therapeutic target. We recently discovered compound 1, a potent hDHODH inhibitor (IC50 = 1.2 nM), able to induce myeloid differentiation in AML cell lines (THP1) in the low nM range (EC50 = 32.8 nM) superior to brequinar’s phase I/II clinical trial (EC50 = 265 nM). Herein, we investigate the 1 drug-like properties observing good metabolic stability and no toxic profile when administered at doses of 10 and 25 mg/kg every 3 days for 5 weeks (Balb/c mice). Moreover, in order to identify a backup compound, we investigate the SAR of this class of compounds. Inside the series, 17 is characterized by higher potency in inducing myeloid differentiation (EC50 = 17.3 nM), strong proapoptotic properties (EC50 = 20.2 nM), and low cytotoxicity toward non-AML cells (EC30(Jurkat) > 100 μM).

Highlights

Human dihydroorotate dehydrogenase is a flavin-dependent enzyme that plays a fundamental role in de novo pyrimidine biosynthesis
HDHODH has been validated as a therapeutic target in diseases that involve wide cellular proliferation, such as autoimmune diseases and cancer.2−4 Small molecules that can interfere with hDHODH enzymatic activity by targeting the host’s pyrimidine synthesis may show great potential in reducing viral replication against a broad spectrum of viruses.5,6 hDHODH was initially included in the list of therapeutic options to be tested against SARS-CoV-2 infected cells
As the most common acute leukemia in adults, acute myelogenous leukemia (AML) affects the myeloid lineage of white blood cells; if left untreated, it is typically fatal within weeks or months, while current chemotherapies give an over-five-year survival rate of only around 25%

Summary

Introduction

Human dihydroorotate dehydrogenase (hDHODH, EC 1.3.99.11) is a flavin-dependent enzyme that plays a fundamental role in de novo pyrimidine biosynthesis. HDHODH has been validated as a therapeutic target in diseases that involve wide cellular proliferation, such as autoimmune diseases and cancer.− Small molecules that can interfere with hDHODH enzymatic activity by targeting the host’s pyrimidine synthesis may show great potential in reducing viral replication against a broad spectrum of viruses. hDHODH was initially included in the list of therapeutic options to be tested against SARS-CoV-2 infected cells.. HDHODH has been validated as a therapeutic target in diseases that involve wide cellular proliferation, such as autoimmune diseases and cancer.− Small molecules that can interfere with hDHODH enzymatic activity by targeting the host’s pyrimidine synthesis may show great potential in reducing viral replication against a broad spectrum of viruses. hDHODH was initially included in the list of therapeutic options to be tested against SARS-CoV-2 infected cells.7 It was validated as a target for COVID-198,9 and became one of the most interesting therapeutic options for this disease.−. The mechanism that associates hDHODH inhibition with myeloid differentiation had not been fully under-

Methods

Results

Conclusion