Dapansutrile (OLT1177) is an inhibitor of the

NLRP3 NLR family pyrin domain containing 3 (NLRP3) (previously known as NACHT, LRR and PYD domains-containing protein 3 ALP3and cryopyrin), is a protein that in humans is encoded by the ''NLRP3'' gene located on the long arm of chromosome 1. NLRP3 is ...

(nucleotide-binding domain leucine-rich repeat and pyrin domain containing receptor 3)

inflammasome Inflammasomes are cytosolic multiprotein oligomers of the innate immune system responsible for the activation of inflammatory responses. Activation and assembly of the inflammasome promotes proteolytic cleavage, maturation and secretion of pro-in ...

. An

can be defined as an immune system

receptor Receptor may refer to: * Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a ...

that induces inflammation through the activation of

caspase 1 Caspase-1/Interleukin-1 converting enzyme (ICE) is an evolutionarily conserved enzyme that proteolytically cleaves other proteins, such as the precursors of the inflammatory cytokines interleukin 1β and interleukin 18 as well as the pyroptosis ...

and

caspase 11 Murine caspase-11, and its human homologs caspase-4 and caspase-5, are mammalian intracellular receptor proteases activated by TLR4 and TLR3 signaling during the innate immune response. Caspase-11, also termed the non-canonical inflammasome, ...

when it is triggered by damaged cells, microbial pathogens, and stress.

is a canonical

. The NLRP3 inflammasome comprises NLRP3, the apoptosis spec-like protein (ASC) and the caspase-1 (Figure 1). The NLRP3 inflammasome forms by binding to pattern recognition receptors (PRRs) and damage associated molecular patterns (DAMPS) that activate

which then signals for the secretion of pro-inflammatory cytokines

IL-1β Interleukin-1 beta (IL-1β) also known as leukocytic pyrogen, leukocytic endogenous mediator, mononuclear cell factor, lymphocyte activating factor and other names, is a cytokine protein that in humans is encoded by the ''IL1B'' gene."Catabolin" ...

and IL-18 resulting in

pyroptosis Pyroptosis is a highly inflammatory form of Lysis, lytic programmed cell death that occurs most frequently upon infection with intracellular pathogens and is likely to form part of the antimicrobial response. This process promotes the rapid clearanc ...

Constant activation of the NLRP3

is believed to play a direct or indirect role in acute arthritis,

atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheroma, atheromatous plaque. At onset there are usu ...

and various

neurodegenerative diseases A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic ...

such as

multiple sclerosis Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...

(MS),

Alzheimer's disease Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...

(AD), and

Parkinson's Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...

disease (PD)^,^,. This drug was developed by Olactec Therapeutics with the purpose of decreasing

peripheral

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

by binding to the NLRP3 protein and inhibiting the formation of the NLRP3

. Interestingly, dapansutrile has also been found to reduce levels of pro inflammatory cytokines IL-18 without interfering with TNF-α levels. Stressed cells in the system can ignite the

NLRP3 inflammasome Inflammasomes are cytosolic multiprotein oligomers of the innate immune system responsible for the activation of inflammatory responses. Activation and assembly of the inflammasome promotes proteolytic cleavage, maturation and secretion of pro-in ...

which in turn produces the secretion inflammatory

cytokine Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...

s such as

and IL-18. Dapansutrile has tested in clinical trials and has been proposed as a beneficial compound for the remedy of

osteoarthritis Osteoarthritis (OA) is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone which affects 1 in 7 adults in the United States. It is believed to be the fourth leading cause of disability in the w ...

, and gouty arthritis. Nevertheless, other preclinical research has proposed dapansutrile to be potentially beneficial for

heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...

and

Molecular Structure and Properties

Dapansutrile is a β-sulfonyl nitrile compound with four carbon, seven hydrogen, one nitrogen, two oxygen, and one sulfur atom (Figure 2). The molecular formula of this compound is C₄H₇NO₂S, and it carries a

molecular weight A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...

of 133.7 g/mol. Compound acknowledged by the names of dapansutrile, OLT1177, and 3-(methylsulfonyl)propanenitrile.

Synthesis

OLT1177 is synthesized by

alkylation Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting ...

of sodium methanesulfinate with 3-bromopropionitrile. This reaction produces crude methylsulfonylpropionitrile which is then purified through dissolution into

acetone Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscib ...

, filtration of the sodium bromide bi-product, solvent exchange via distillation, and recrystallization from

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...

Dapansutrile's Mechanism of Action

Dapansutrile's Reaction Pathways

Dapansutrile denoted as a β-sulfonyl nitrile molecule. Its mechanism of action induces a

Pinner reaction The Pinner reaction refers to the acid catalysed reaction of a nitrile with an alcohol to form an imino ester salt (alkyl imidate salt); this is sometimes referred to as a Pinner salt. The reaction is named after Adolf Pinner, who first described ...

which is initiated by reacting with

thiol In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl gro ...

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

s and

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ...

s. Thus, leading to the formation of thiomidates, imidates and amidines respectively. The

nitrile group In organic chemistry, a nitrile is any organic compound that has a functional group. The prefix ''cyano-'' is used interchangeably with the term ''nitrile'' in industrial literature. Nitriles are found in many useful compounds, including meth ...

of OLT1177 is still not denoted as a

covalent A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms ...

noncovalent In chemistry, a non-covalent interaction differs from a covalent bond in that it does not involve the sharing of electrons, but rather involves more dispersed variations of electromagnetic interactions between molecules or within a molecule. The c ...

, irreversible or non-reversible inhibitor as there are currently no studies about its reactivity. Nevertheless, some researchers believe that dapansutrile promotes inhibition of

through

covalent bond A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms ...

s (Figure 4).

Summary Biological Effects of Dapansutrile

Pharmacokinetics

Selectivity

Dapansutrile targets the inhibition of the

ATPase and thus blocks the activation of the

's ASC, and

caspase-1 Caspase-1/Interleukin-1 converting enzyme (ICE) is an evolutionarily conserved enzyme that proteolytically cleaves other proteins, such as the precursors of the inflammatory cytokines interleukin 1β and interleukin 18 as well as the pyroptosis ...

interaction; thereby preventing the assembly of the

and inflammatory signals such as

and IL-18. This drug also inhibits

. Nevertheless, the drug does not impact the

mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is ...

levels of the

, ASC, caspase-1, IL-1β, and IL-18

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

s. Research of dapansutrile presents that the compound solely inhibits the

Murine The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. Members of this subfamily are called murines. In terms of species richness, this subfamily is larger than all mammal families excep ...

macrophage Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cel ...

s were used and stimulated with

lipopolysaccharide Lipopolysaccharides (LPS) are large molecules consisting of a lipid and a polysaccharide that are bacterial toxins. They are composed of an O-antigen, an outer core, and an inner core all joined by a covalent bond, and are found in the outer m ...

s and either

flagellin Flagellin is a globular protein that arranges itself in a hollow cylinder to form the filament in a bacterial flagellum. It has a mass of about 30,000 to 60,000 daltons. Flagellin is the principal component of bacterial flagella, and is present ...

or the dsDNA analog Poly(dA:dT) to activate

s such as

NLRC4 NLR family CARD domain-containing protein 4 is a protein that in humans is encoded by the ''NLRC4'' gene. Structure The NLRC4 protein is highly conserved across mammalian species. It bears homology to the ''C. elegans'' Ced4 protein. It contai ...

and AIM 2 respectively. When Dapansutrile was added they found no difference in the release of

TNF-α Tumor necrosis factor (TNF, cachexin, or cachectin; formerly known as tumor necrosis factor alpha or TNF-α) is an adipokine and a cytokine. TNF is a member of the TNF superfamily, which consists of various transmembrane proteins with a homolog ...

and

s to when these

s were activated.

Other Drug Targets

Other known targets of dapansutrile include several

phosphorylated In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, whi ...

kinase In biochemistry, a kinase () is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule don ...

s such as Src;

Fyn Funen ( da, Fyn, ), with an area of , is the third-largest island of Denmark, after Zealand and Vendsyssel-Thy. It is the 165th-largest island in the world. It is located in the central part of the country and has a population of 469,947 as of ...

;

HcK Tyrosine-protein kinase HCK is an enzyme that in humans is encoded by the ''HCK'' gene. Function The protein encoded by this gene is a protein-tyrosine kinase that is predominantly expressed in hemopoietic cell types, and belongs to the Src f ...

;

STAT3 Signal transducer and activator of transcription 3 (STAT3) is a transcription factor which in humans is encoded by the ''STAT3'' gene. It is a member of the STAT protein family. Function STAT3 is a member of the STAT protein family. In respons ...

. Human monocyte derived macrophages (HMDM) cells were stimulated with

, and

nigericin Nigericin is an antibiotic derived from '' Streptomyces hygroscopicus''. Its isolation was described in the 1950s, and in 1968 the structure could be elucidated by X-ray crystallography. The structure and properties of nigericin are similar to th ...

. Dapansutrile was then added and they found a 26%, 35%, 43% and 33% reduction of these

s respectively.

Dosages

In vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

:'' Human derived macrophages were cultured to study the effect of dapansutrile

production. It was found that dapansutrile at a 1 µM dose inhibited secretion of

by 60%, and IL-18 levels by 70%. The drug was also found to selectively inhibit

at 10 µM. ''

In vivo Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...

:'' A phase one

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...

of 35 subjects was conducted to establish the safety of dapansutrile. The daily mean plasma concentration maximum (C_max) for a single oral dose of dapansutrile was 2,700 ng/mL for the 100-mg dose, 9,800 ng/mL for the 300 mg dose and 32,00 ng/mL for the 1,000 mg dose (Figure 5). Dapansutrile was also studied if given repeatedly once per day for 8 days with a dose of either 100 mg, and 300 mg, or 1,000 mg. The subjects mean plasma concentration on day 8 were 4,800 ng/mL for the 100 mg dose, 15,800 ng/mL for the 300 mg dose and 41,400 ng/mL for the 1,000 mg dose. Plasma Concentration after a Single Dose of OTL1177

Plasma Concentration after a Single Dose of OTL1177

Pharmacodynamics

Safety and Efficacy of Dapansutrile

In the Marchetti et al. study, seven of the 35 subjects reported

adverse events An adverse event (AE) is any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. An adverse event can ther ...

. Five of the cases were in the single dose study while two cases were in the multi-regimen group. However, the adverse effects were considered unrelated to dapansutrile. Subjects presented no changes in

blood pressure Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" r ...

(systolic and diastolic),

urinalysis Urinalysis, a portmanteau of the words ''urine'' and ''analysis'', is a panel of medical tests that includes physical (macroscopic) examination of the urine, chemical evaluation using urine test strips, and microscopic examination. Macroscopic e ...

heart rate Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excr ...

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

function

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

s or

acute phase proteins Acute-phase proteins (APPs) are a class of proteins whose concentrations in blood plasma either increase (positive acute-phase proteins) or decrease (negative acute-phase proteins) in response to inflammation. This response is called the ''acute-p ...

in the cohort after an 8-day trial with up to daily 1,000 mg dosing of dapansutrile.

Potential Therapeutic Applications

Neurodegenerative diseases

Multiple Sclerosis: Multiple sclerosis (MS) is a

neurodegenerative disease A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic ...

characterized by the

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...

deteriorating

myelin Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be ...

Myelin Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be ...

damage leads to the disruption of neuronal signaling, and dysregulrated inflammatory levels. Dapansutrile was used in the Experimental Autoimmune Encephalomyelitis (EAE) mouse model to understand its possible underlying effects for MS. It was found that mice fed with the dapansutrile diet protected the mice from

demyelination A demyelinating disease is any disease of the nervous system in which the myelin sheath of neurons is damaged. This damage impairs the conduction of signals in the affected nerves. In turn, the reduction in conduction ability causes deficiency i ...

in the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spi ...

as well as decreased their levels of

interleukin Interleukins (ILs) are a group of cytokines (secreted proteins and signal molecules) that are expressed and secreted by white blood cells (leukocytes) as well as some other body cells. The human genome encodes more than 50 interleukins and related ...

and IL-18. Currently, it is unclear whether the drug could inhibit

microglia Microglia are a type of neuroglia (glial cell) located throughout the brain and spinal cord. Microglia account for about 7% of cells found within the brain. As the resident macrophage cells, they act as the first and main form of active immune de ...

l reactivity, but currently it has no known benefits to aid in the prevention of

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

and

cognitive function Cognitive skills, also called cognitive functions, cognitive abilities or cognitive capacities, are brain-based skills which are needed in acquisition of knowledge, manipulation of information and reasoning. They have more to do with the mechanisms ...

Inflammation

Gouty Arthritis:

Gouty arthritis Gout ( ) is a form of inflammatory arthritis characterized by recurrent attacks of a red, tender, hot and swollen joint, caused by deposition of monosodium urate monohydrate crystals. Pain typically comes on rapidly, reaching maximal intensit ...

is an inflammatory joint disorder, partly induced to the activation of the

and excess

activation which leads to gout attacks. This is due to excess uric acid in the blood which promotes the formation of uric acid crystals in the joints. Uric acid is a known danger signal and induce the cleavage signal of the caspase-1 NLRP3 inflammasome. Animal Model Experiments: In 2018, two

murine The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. Members of this subfamily are called murines. In terms of species richness, this subfamily is larger than all mammal families excep ...

models were used to validate Dapansutrile as a drug beneficial for acute joint inflammation. They injected

zymosan Zymosan is a glucan with repeating glucose units connected by β-1,3-glycosidic linkages. It binds to TLR 2 and Dectin-1 (CLEC7A C-type lectin domain family 7 member A or Dectin-1 is a protein that in humans is encoded by the ''CLEC7A'' gene. C ...

or monosodium urate crystals in order to induce gouty arthritis in mice. OLT1177 was then either injected

intraperitoneally Intraperitoneal injection or IP injection is the injection of a substance into the peritoneum (body cavity). It is more often applied to animals than to humans. In general, it is preferred when large amounts of blood replacement fluids are needed ...

or through their diet. In essence, the drug reduced

joint A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw ...

, as well as

levels demonstrating its therapeutic benefit for this disease. Clinical Trials: As for clinical trials, Olatec Therapeutics also conducted a phase 2.a trials where Dapansutrile was given to 29 subjects with gouty arthritis.

Cardiovascular Diseases

Acute Myocardial Infarction/ Heart Attack: One of the major downstream effects of having coronary artery disease is possibility of having an acute myocardial infarction or heart attack. In mouse models, Dapansutrile was found to decrease

infarct Infarction is tissue death (necrosis) due to Ischemia, inadequate blood supply to the affected area. It may be caused by Thrombosis, artery blockages, rupture, mechanical compression, or vasoconstriction. The resulting lesion is referred to as a ...

size a dose-dependent manner. Heart Failure: Olatec Therapeutics conducted a phase 1

for Dapansutrile as a potential therapeutic for systolic heart failure. They have carried out a Phase 1 double blinded study with a total of 30 subjects to assess the drug's safety and pharmacodynamics. The drug was given in capsule form and the subjects were divided into 3 cohorts. Each cohort had 8 subjects taking an oral capsule with 100 mg Dapansutrile while 2 subjects were given the placebo capsule. Although the completion date of this clinical trial was on November 21, 2019, the results of the study have not yet been published. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) / COVID-19: Dapansutrile has been proposed by a number of scientists as a measure to reduce cardiovascular outcomes that seem to be brought on by

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December ...

. The rationale behind using Dapansutrile is to inhibit the

and reduce the chances of a

cytokine storm A cytokine storm, also called hypercytokinemia, is a physiological reaction in humans and other animals in which the innate immune system causes an uncontrolled and excessive release of pro-inflammatory signaling molecules called cytokines. Norma ...

which seems to cause multi-organ failure in

patients. Subjects with

have shown to have an increased concentration of pro-inflammatory cytokines resulting in the

, and thus producing an exhaustion of

lymphocyte A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic ad ...

not only activates cytokines but other key players that can inflict myocardial damages, and Acute Respiratory Distress Syndrome (ARDS), and its inhibition has been found to deter these outcomes. Thus, dapansutrile is proposed as a possible mediator to relief and prevent

symptoms and effects.

References

{{Reflist Sulfonyl groups Nitriles Anti-inflammatory agents