The glutamine antagonist 6-diazo-5-oxo-l-norleucine (DON) exhibits remarkable anticancer efficacy; however, its therapeutic potential is hindered by its toxicity to gastrointestinal (GI) tissues. We recently reported the discovery of DRP-104, a tumor-targeted DON prodrug with excellent efficacy and tolerability, which is currently in clinical trials. However, DRP-104 exhibits limited aqueous solubility, and the instability of its isopropyl ester promoiety leads to the formation of an inactive M1-metabolite, reducing overall systemic prodrug exposure. Herein, we aimed to synthesize DON prodrugs with various ester and amide promoieties with improved solubility, GI stability, and DON tumor delivery. Twenty-one prodrugs were synthesized and characterized in stability and pharmacokinetics studies. Of these, P11, tert-butyl-(S)-6-diazo-2-((S)-2-(2-(dimethylamino)acetamido)-3-phenylpropanamido)-5-oxo-hexanoate, showed excellent metabolic stability in plasma and intestinal homogenate, high aqueous solubility, and high tumor DON exposures and preserved the ideal tumor-targeting profile of DRP-104. In conclusion, we report a new generation of glutamine antagonist prodrugs with improved physicochemical and pharmacokinetic attributes.

• MeSH
• diazooxonorleucin farmakokinetika   MeSH
• estery terapeutické užití   MeSH
• glutamin MeSH
• lidé MeSH
• nádory * farmakoterapie   MeSH
• prekurzory léčiv * chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

6-Diazo-5-oxo-l-norleucine (DON) is a glutamine antagonist that suppresses cancer cell metabolism but concurrently enhances the metabolic fitness of tumor CD8+ T cells. DON showed promising efficacy in clinical trials; however, its development was halted by dose-limiting gastrointestinal (GI) toxicities. Given its clinical potential, we designed DON peptide prodrugs and found DRP-104 [isopropyl(S)-2-((S)-2-acetamido-3-(1H-indol-3-yl)-propanamido)-6-diazo-5-oxo-hexanoate] that was preferentially bioactivated to DON in tumor while bioinactivated to an inert metabolite in GI tissues. In drug distribution studies, DRP-104 delivered a prodigious 11-fold greater exposure of DON to tumor versus GI tissues. DRP-104 affected multiple metabolic pathways in tumor, including decreased glutamine flux into the TCA cycle. In efficacy studies, both DRP-104 and DON caused complete tumor regression; however, DRP-104 had a markedly improved tolerability profile. DRP-104's effect was CD8+ T cell dependent and resulted in robust immunologic memory. DRP-104 represents a first-in-class prodrug with differential metabolism in target versus toxicity tissue. DRP-104 is now in clinical trials under the FDA Fast Track designation.

• MeSH
• CD8-pozitivní T-lymfocyty metabolismus   MeSH
• diazooxonorleucin farmakologie   terapeutické užití   MeSH
• glutamin metabolismus   MeSH
• inhibitory enzymů terapeutické užití   MeSH
• lidé MeSH
• nádory * farmakoterapie   MeSH
• prekurzory léčiv * farmakologie   terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The carbon and nitrogen components of glutamine are used for multiple biosynthetic processes by tumors. Glutamine metabolism and the therapeutic potential of glutamine antagonists (GA), however, are incompletely understood in malignant peripheral nerve sheath tumor (MPNST), an aggressive soft tissue sarcoma observed in patients with neurofibromatosis type I. We investigated glutamine dependence of MPNST using JHU395, a novel orally bioavailable GA prodrug designed to circulate inert in plasma, but permeate and release active GA within target tissues. Human MPNST cells, compared with Schwann cells derived from healthy peripheral nerve, were selectively susceptible to both glutamine deprivation and GA dose-dependent growth inhibition. In vivo, orally administered JHU395 delivered active GA to tumors with over 2-fold higher tumor-to-plasma exposure, and significantly inhibited tumor growth in a murine flank MPNST model without observed toxicity. Global metabolomics studies and stable isotope-labeled flux analyses in tumors identified multiple glutamine-dependent metabolites affected, including prominent effects on purine synthesis. These data demonstrate that glutamine antagonism is a potential antitumor strategy for MPNST.

• MeSH
• glutamin antagonisté a inhibitory   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory nervové pochvy farmakoterapie   MeSH
• prekurzory léčiv farmakologie   MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Neutral sphingomyelinase 2 (nSMase2) catalyzes the cleavage of sphingomyelin to phosphorylcholine and ceramide, an essential step in the formation and release of exosomes from cells that is critical for intracellular communication. Chronic increase of brain nSMase2 activity and related exosome release have been implicated in various pathological processes, including the progression of Alzheimer's disease (AD), making nSMase2 a viable therapeutic target. Recently, we identified phenyl (R)-(1-(3-(3,4-dimethoxyphenyl)-2,6-dimethylimidazo[1,2-b]pyridazin-8-yl)pyrrolidin-3-yl)carbamate 1 (PDDC), the first nSMase2 inhibitor that possesses both favorable pharmacodynamics and pharmacokinetic (PK) parameters, including substantial oral bioavailability, brain penetration, and significant inhibition of exosome release from the brain in vivo. Herein we demonstrate the efficacy of 1 (PDDC) in a mouse model of AD and detail extensive structure-activity relationship (SAR) studies with 70 analogues, unveiling several that exert similar or higher activity against nSMase2 with favorable pharmacokinetic properties.

• MeSH
• Alzheimerova nemoc farmakoterapie   patologie   MeSH
• exozómy metabolismus   MeSH
• inhibitory enzymů chemie   metabolismus   farmakologie   terapeutické užití   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• mozek metabolismus   MeSH
• myši transgenní MeSH
• myši MeSH
• pyridaziny chemie   metabolismus   terapeutické užití   MeSH
• sfingomyelinfosfodiesterasa antagonisté a inhibitory   metabolismus   farmakologie   MeSH
• tělesná hmotnost účinky léků   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

2-(Phosphonomethyl)-pentanedioic acid (2-PMPA) is a potent (IC50 = 300 pM) and selective inhibitor of glutamate carboxypeptidase II (GCPII) with efficacy in multiple neurological and psychiatric disease preclinical models and more recently in models of inflammatory bowel disease (IBD) and cancer. 2-PMPA (1), however, has not been clinically developed due to its poor oral bioavailability (<1%) imparted by its four acidic functionalities (c Log P = -1.14). In an attempt to improve the oral bioavailability of 2-PMPA, we explored a prodrug approach using (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl (ODOL), an FDA-approved promoiety, and systematically masked two (2), three (3), or all four (4) of its acidic groups. The prodrugs were evaluated for in vitro stability and in vivo pharmacokinetics in mice and dog. Prodrugs 2, 3, and 4 were found to be moderately stable at pH 7.4 in phosphate-buffered saline (57, 63, and 54% remaining at 1 h, respectively), but rapidly hydrolyzed in plasma and liver microsomes, across species. In vivo, in a single time-point screening study in mice, 10 mg/kg 2-PMPA equivalent doses of 2, 3, and 4 delivered significantly higher 2-PMPA plasma concentrations (3.65 ± 0.37, 3.56 ± 0.46, and 17.3 ± 5.03 nmol/mL, respectively) versus 2-PMPA (0.25 ± 0.02 nmol/mL). Given that prodrug 4 delivered the highest 2-PMPA levels, we next evaluated it in an extended time-course pharmacokinetic study in mice. 4 demonstrated an 80-fold enhancement in exposure versus oral 2-PMPA (AUC0-t: 52.1 ± 5.9 versus 0.65 ± 0.13 h*nmol/mL) with a calculated absolute oral bioavailability of 50%. In mouse brain, 4 showed similar exposures to that achieved with the IV route (1.2 ± 0.2 versus 1.6 ± 0.2 h*nmol/g). Further, in dogs, relative to orally administered 2-PMPA, 4 delivered a 44-fold enhanced 2-PMPA plasma exposure (AUC0-t for 4: 62.6 h*nmol/mL versus AUC0-t for 2-PMPA: 1.44 h*nmol/mL). These results suggest that ODOL promoieties can serve as a promising strategy for enhancing the oral bioavailability of multiply charged compounds, such as 2-PMPA, and enable its clinical translation.

• MeSH
• aplikace orální MeSH
• biologická dostupnost MeSH
• jaterní mikrozomy metabolismus   MeSH
• myši MeSH
• organofosforové sloučeniny aplikace a dávkování   chemie   metabolismus   farmakokinetika   MeSH
• prekurzory léčiv aplikace a dávkování   chemie   metabolismus   farmakokinetika   MeSH
• psi MeSH
• tkáňová distribuce MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

6-Diazo-5-oxo-l-norleucine (DON) is a glutamine antagonist with robust anticancer efficacy; however, its therapeutic potential was hampered by its biodistribution and toxicity to normal tissues, specifically gastrointestinal (GI) tissues. To circumvent DON's toxicity, we synthesized a series of tumor-targeted DON prodrugs designed to circulate inert in plasma and preferentially activate over DON in tumor. Our best prodrug 6 (isopropyl 2-(6-acetamido-2-(adamantane-1-carboxamido)hexanamido)-6-diazo-5-oxohexanoate) showed stability in plasma, liver, and intestinal homogenates yet was readily cleaved to DON in P493B lymphoma cells, exhibiting a 55-fold enhanced tumor cell-to-plasma ratio versus that of DON and resulting in a dose-dependent inhibition of cell proliferation. Using carboxylesterase 1 knockout mice that were shown to mimic human prodrug metabolism, systemic administration of 6 delivered 11-fold higher DON exposure to tumor (target tissue; AUC0- t = 5.1 nmol h/g) versus GI tissues (toxicity tissue; AUC0- t = 0.45 nmol h/g). In summary, these studies describe the discovery of a glutamine antagonist prodrug that provides selective tumor exposure.

• MeSH
• acetylace MeSH
• antitumorózní látky aplikace a dávkování   MeSH
• diazooxonorleucin aplikace a dávkování   farmakokinetika   MeSH
• karboxylesterhydrolasy genetika   MeSH
• lidé MeSH
• lysin chemie   MeSH
• myši knockoutované MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• plocha pod křivkou MeSH
• prasata MeSH
• prekurzory léčiv chemie   MeSH
• systémy cílené aplikace léků * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH