Compounds and their uses

Abstract

This invention relates to compounds, pharmaceutical compositions, and methods of using the disclosed compounds for inhibiting PARP.

Description

[0001] This application claims benefit of U.S. Provisional Application No. 60 / 250,132, filed Dec. 1, 2000, and U.S. Provisinal Application No. 60 / 310,274, filed Aug. 9, 2001, the entire contents of each of which is incorporated herein by reference.[0002] The present invention relates to inhibitors of the nuclear enzyme poly(adenosine 5′-diphospho-ribose) polymerase [“poly(ADP-ribose) polymerase” or “PARP”, which is also referred to as ADPRT (NAD:protein (ADP-ribosyl transferase (polymersing)) and PARS (poly(ADP-ribose) synthetase) and provides compounds and compositions containing the disclosed compounds. Moreover, the present invention provides methods of using the disclosed PARP inhibitors to prevent and / or treat tissue damage resulting from cell damage or death due to necrosis or apoptosis; neural tissue damage resulting from, for example, ischemia and reperfusion injury, such as cerebral ischemic stroke, head trauma or spinal cord injury; neurological disorders and neurodegenera...

AI Technical Summary

Benefits of technology

[0002] The present invention relates to inhibitors of the nuclear enzyme poly(adenosine 5′-diphospho-ribose) polymerase [“poly(ADP-ribose) polymerase” or “PARP”, which is also referred to as ADPRT (NAD:protein (ADP-ribosyl transferase (polymersing)) and PARS (poly(ADP-ribose) synthetase) and provides compounds and compositions containing the disclosed compounds. Moreover, the present invention provides methods of using the disclosed PARP inhibitors to prevent and / or treat tissue damage resulting from cell damage or death due to necrosis or apoptosis; neural tissue damage resulting from, for example, ischemia and reperfusion injury, such as cerebral ischemic stroke, head trauma or spinal cord injury; neurological disorders and neurodegenerative diseases, such as, for example, Parkinson's or Alzheimer's diseases and multiple sclerosis; to prevent or treat vascular stroke; to treat or prevent cardiovascular disorders, such as, for example, myocardial infarction; to treat other conditions and / or disorders such as, for example, age-related muscular degeneration, AIDS and other immune senescence diseases, inflammation, arthritis, gout, atherosclerosis, cachexia, cancer, degenerative diseases of skeletal muscle involving replicative senescence, diabetes (such as diabetes mellitus), inflammatory bowel disorders (such as colitis and Crohn's disease), acute pancreatitis, mucositis, hemorrhagic shock, splanchnic artery occlusion shock, multiple organ failure (such as involving any of the kidney, liver, renal, pulmonary, retinal, pancreatic and / or skeletal muscle systems), acute autoimmune thyroiditis, muscular dystrophy, osteoarthritis, osteoporosis, chronic and acute pain (such as neuropathic pain), renal failure, retinal ischemia, septic shock (such as endotoxic shock), local and / or remote endothelial cell dysfunction (such are recognized by endo-dependent relaxant responses and up-regulation of adhesion molecules), inflammation and skin aging; to extend the lifespan and proliferative capacity of cells, such as, for example, as general mediators in the generation of oxidants, proinflammatory mediators and / or cytokines, and general mediators of leukocyte infiltration, calcium ion overload, phospholipid peroxidation, impaired nitric oxide metabolism and / or reduced ATP production; to alter gene expression of senescent cells; or to radiosensitize hypoxic tumor cells.

[0004] Extensive PARP activation leads to severe depletion of NAD in cells suffering from massive DNA damage. The short life of poly(ADP-ribose) (half-life<1 min) results in a rapid turnover rate. Once poly(ADP-ribose) is formed, it is quickly degraded by the constitutively active poly(ADP-ribose) glycohydrolase (PARG), together with phosphodiesterase and (ADP-ribose) protein lyase. PARP and PARG form a cycle that converts a large amount of NAD to ADP-ribose. In less than an hour, over-stimulation of PARP can cause a drop of NAD and ATP to less than 20% of the normal level. Such a scenario is especially detrimental during ischaemia when deprivation of oxygen has already drastically compromised cellular energy output. Subsequent free radical production during reperfusion is assumed to be a major cause of tissue damage. Part of the ATP drop, which is typical in many organs during ischaemia and reperfusion, could be linked to NAD depletion due to poly(ADP-ribose) turnover. Thus, PARP or PARG inhibition is expected to preserve the cellular energy level to potentiate the survival of ischaemic tissues after insult.

[0013] Evidence also exists that PARP inhibitors are useful for treating inflammatory bowel disorders, such as colitis. Salzman et al., “Role of Peroxynitrite and Poly(ADP-Ribose)Synthase Activation Experimental Colitis,” Japanese J. Pharm., 75, Supp. I: 15 (1997). Specifically, Colitis was induced in rats by intraluminal administration of the hapten trinitrobenzene sulfonic acid in 50% ethanol. Treated rats received 3-aminobenzamide, a specific inhibitor of PARP activity. Inhibition of PARP activity reduced the inflammatory response and restored the morphology and the energetic status of the distal colon. See also, Southan et al., “Spontaneous Rearrangement of Aminoalkylithioureas into Mercaptoalkylguanidines, a Novel Class of Nitric Oxide Synthase Inhibitors with Selectivity Towards the Inducible Isoform”, Br. J. Pharm., 117:619-32 (1996); and Szabó et al., “Mercaptoethylguanidine and Guanidine Inhibitors of Nitric Oxide Synthase React with Peroxynitrite and Protect Against Peroxynitrite-induced Oxidative Damage”, J. Biol. Chem., 272:9030-36 (1997).

[0017] PARP inhibitors have been used to treat cancer. Suto et al., “Dihydroisoquinolinones: The Design and Synthesis of a New Series of Potent Inhibitors of Poly(ADP-Ribose) Polymerase”, Anticancer Drug Des., 7:107-17 (1991). In addition, Suto et al., U.S. Pat. No. 5,177,075, discusses several isoquinolines used for enhancing the lethal effects of ionizing radiation or chemotherapeutic agents on tumor cells. Weltin et al., “Effect of 6(5H)-Phenanthridinone, an Inhibitor of Poly(ADP-ribose) Polymerase, on Cultured Tumor Cells”, Oncol. Res., 6:9, 399-403 (1994), discusses the inhibition of PARP activity, reduced proliferation of tumor cells, and a marked synergistic effect when tumor cells are co-treated with an alkylating drug.

[0023] There continues to be a need for effective and potent PARP inhibitors which produce minimal side-effects. The present invention provides compounds, compositions for, and methods of, inhibiting PARP activity for treating and / or preventing cellular, tissue and / or organ damage resulting from cell damage or death due to, for example, necrosis or apoptosis. The compounds and compositions of the present invention are specifically useful in ameliorating, treating and / or preventing neural tissue or cell damage, including that following focal ischemia and reperfusion injury. Generally, inhibition of PARP activity spares the cell from energy loss, preventing irreversible depolarization of the neurons and, thus, provides neuroprotection. While not wishing to be bound by any mechanistic theory, the inhibition of PARP activity by use of the compounds, compositions and methods of the present invention is believed to protect cells, tissue and organs by protection against the ill-effects of reactive free radicals and nitric oxide. The present invention therefore also provides methods of treating and / or preventing cells, tissue and / or organs from reactive free radical and / or nitric oxide induced damage or injury. SUMMARY OF THE INVENTION

Problems solved by technology

However, DNA damage causes an immediate activation of PARP by up to 500-fold.

Extensive PARP activation leads to severe depletion of NAD in cells suffering from massive DNA damage.

The short life of poly(ADP-ribose) (half-life<1 min) results in a rapid turnover rate.

Such a scenario is especially detrimental during ischaemia when deprivation of oxygen has already drastically compromised cellular energy output.

Subsequent free radical production during reperfusion is assumed to be a major cause of tissue damage.

During major cellular stresses the extensive activation of PARP can rapidly lead to cell damage or death through depletion of energy stores.

This excess release of glutamate in turn causes over-stimulation (excitotoxicity) of N-methyl-D-aspartate (NMDA), AMPA, Kainate and MGR receptors, which open ion channels and permit uncontrolled ion flow (e.g., Ca2+ and Na+ into the cells and K+ out of the cells) leading to overstimulation of the neurons.

The over-stimulated neurons secrete more glutamate, creating a feedback loop or domino effect which ultimately results in cell damage or death via the production of proteases, lipases and free radicals.

Attempts to prevent excitotoxicity by blocking NMDA, AMPA, Kainate and MGR receptors have proven difficult because each receptor has multiple sites to which glutamate may bind and hence finding an effective mix of antagonists or universal antagonist to prevent binding of glutamate to all of the receptor and allow testing of this theory, has been difficult.

Moreover, many of the compositions that are effective in blocking the receptors are also toxic to animals.

As such, there is presently no known effective treatment for glutamate abnormalities.

However, effective use of these PARP inhibitors, in the ways discussed above, has been limited by the concurrent production of unwanted side-effects (Milam et al., “Inhibitors of Poly(Adenosine Diphosphate-Ribose) Synthesis; Effect on Other Metabolic Processes”, Science, 223:589-91 (1984)).

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