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Other names | encukalner, azetukalner |
Routes of administration | By mouth |
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Formula | C23H29FN2O |
Molar mass | 368.496 g·mol−1 |
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XEN1101 (encukalner) is an experimental small molecule anticonvulsant and selective Kv7.2/Kv7.3 potassium channel opener being investigated as a treatment for refractory focal onset seizures [1] [2] [3] [4] [5] and major depressive disorder. [5]
XEN1101 works by selectively opening the KCNQ2/3 (Kv7.2/Kv7.3) voltage-gated potassium channels via positive allosteric modulation. The opening of these voltage-gated potassium channels, which are critical regulators of neuronal excitability, leads to an increase in the flow of potassium ions out of neurons. The loss of positively charged potassium ions results in the inside of the neuron becoming negatively charged and hyperpolarized. This hyperpolarized resting state reduces the ability of the neuron to fire, thereby decreasing the likelihood of seizures. [2] [3] [5]
This mechanism of action shares similarities with the medication retigabine, which was withdrawn from the market in 2017 due to its link to skin pigmentation and retinitis pigmentosa. [1] [2] [5] [6] XEN1101 has a different structure and does not appear to cause this effect or the development of the chromophoric phenazinium-type dimers that resulted in this side effect in retigabine. [1]
A seizure is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness, to shaking movements involving only part of the body with variable levels of consciousness, to a subtle momentary loss of awareness. These episodes usually last less than two minutes and it takes some time to return to normal. Loss of bladder control may occur.
Topiramate, sold under the brand name Topamax among others, is a medication used to treat epilepsy and prevent migraines. It has also been used in alcohol dependence and essential tremor. For epilepsy this includes treatment for generalized or focal seizures. It is taken orally.
Lamotrigine, sold under the brand name Lamictal among others, is a medication used to treat epilepsy and stabilize mood in bipolar disorder. For epilepsy, this includes focal seizures, tonic-clonic seizures, and seizures in Lennox-Gastaut syndrome. In bipolar disorder, lamotrigine has not been shown to reliably treat acute depression for all groups except in the severely depressed; but for patients with bipolar disorder who are not currently symptomatic, it appears to reduce the risk of future episodes of depression.
Oxcarbazepine, sold under the brand name Trileptal among others, is a medication used to treat epilepsy. For epilepsy it is used for both focal seizures and generalized seizures. It has been used both alone and as add-on therapy in people with bipolar disorder who have had no success with other treatments. It is taken by mouth.
Levetiracetam, sold under the brand name Keppra among others, is a medication used to treat epilepsy. It is used for partial-onset, myoclonic, or tonic–clonic seizures and is taken either by mouth as an immediate or extended release formulation or by injection into a vein.
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate dietary therapy that in conventional medicine is used mainly to treat hard-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates.
Stiripentol, sold under the brand name Diacomit, is an anticonvulsant medication used for the treatment of Dravet syndrome - a serious genetic brain disorder.
Rufinamide is an anticonvulsant medication. It is used in combination with other medication and therapy to treat Lennox–Gastaut syndrome and various other seizure disorders. Rufinamide, a triazole derivative, was developed in 2004 by Novartis Pharma, AG, and is manufactured by Eisai.
Dravet syndrome (DS), previously known as severe myoclonic epilepsy of infancy (SMEI), is an autosomal dominant genetic disorder which causes a catastrophic form of epilepsy, with prolonged seizures that are often triggered by hot temperatures or fever. It is very difficult to treat with anticonvulsant medications. It often begins before one year of age, with six months being the age that seizures, characterized by prolonged convulsions and triggered by fever, usually begin.
Benign familial neonatal seizures (BFNS), also referred to as benign familial neonatal epilepsy (BFNE), is a rare autosomal dominant inherited form of seizures. This condition manifests in newborns as brief and frequent episodes of tonic-clonic seizures with asymptomatic periods in between. Characteristically, seizure activity spontaneously ends during infancy and does not affect childhood development. However, some studies have reported that a minority of children with BFNS consequently develop intellectual disability. Additionally, BFNS increases lifetime susceptibility to seizures as approximately 14% of those afflicted go on to develop epilepsy later in life. There are three known genetic causes of BFNE, two being the voltage-gated potassium channels KCNQ2 (BFNC1) and KCNQ3 (BFNC2) and the third being a chromosomal inversion (BFNC3). There is no obvious correlation between most of the known mutations and clinical variability seen in BFNE.
T-type calcium channels are low voltage activated calcium channels that become inactivated during cell membrane hyperpolarization but then open to depolarization. The entry of calcium into various cells has many different physiological responses associated with it. Within cardiac muscle cell and smooth muscle cells voltage-gated calcium channel activation initiates contraction directly by allowing the cytosolic concentration to increase. Not only are T-type calcium channels known to be present within cardiac and smooth muscle, but they also are present in many neuronal cells within the central nervous system. Different experimental studies within the 1970s allowed for the distinction of T-type calcium channels from the already well-known L-type calcium channels. The new T-type channels were much different from the L-type calcium channels due to their ability to be activated by more negative membrane potentials, had small single channel conductance, and also were unresponsive to calcium antagonist drugs that were present. These distinct calcium channels are generally located within the brain, peripheral nervous system, heart, smooth muscle, bone, and endocrine system.
Kv7.2 (KvLQT2) is a voltage- and lipid-gated potassium channel protein coded for by the gene KCNQ2.
Kv7.3 (KvLQT3) is a potassium channel protein coded for by the gene KCNQ3.
Lacosamide, sold under the brand name Vimpat among others, is a medication used for the treatment of partial-onset seizures and primary generalized tonic-clonic seizures. It is used by mouth or intravenously.
Potassium voltage-gated channel subfamily KQT member 4, also known as voltage-gated potassium channel subunit Kv7.4, is a protein that in humans is encoded by the KCNQ4 gene.
A potassium channel opener is a type of drug which facilitates ion transmission through potassium channels.
Retigabine (INN) or ezogabine (USAN) is an anticonvulsant used as an adjunctive treatment for partial epilepsies in treatment-experienced adult patients. The drug was developed by Valeant Pharmaceuticals and GlaxoSmithKline. It was approved by the European Medicines Agency under the trade name Trobalt on March 28, 2011, and by the United States Food and Drug Administration (FDA), under the trade name Potiga, on June 10, 2011. Production was discontinued in June 2017.
Perampanel, sold under the brand name Fycompa, is an anti-epileptic medication developed by Eisai Co. that is used in addition to other drugs to treat partial seizures and generalized tonic-clonic seizures for people older than twelve years. It was first approved in 2012, and as of 2016, its optimal role in the treatment of epilepsy relative to other drugs was not clear. It was the first antiepileptic drug in the class of selective non-competitive antagonist of AMPA receptors.
Gene therapy is being studied for some forms of epilepsy. It relies on viral or non-viral vectors to deliver DNA or RNA to target brain areas where seizures arise, in order to prevent the development of epilepsy or to reduce the frequency and/or severity of seizures. Gene therapy has delivered promising results in early stage clinical trials for other neurological disorders such as Parkinson's disease, raising the hope that it will become a treatment for intractable epilepsy.
KCNQ2 encephalopathy typically presents with tonic seizures from the first week of life. The seizures can be frequent and often difficult to treat. Seizures can resolve within months or years but can impair the development of several domains such as motor, social, cognitive and language.
XEN1101 is a novel positive allosteric modulator ("opener") of the potassium channel KCNQ2/3 (Kv7.2/7.3) currently being developed by Xenon Pharmaceuticals Inc. for the treatment of focal epilepsy. Potentiating the open state of KCNQ2/3 channels favors a hyperpolarized resting state. This mechanism has been clinically proven effective for focal onset seizures using the KCNQ2/3 opener, retigabine.
XEN1101 (Xenon Pharmaceuticals), part of a class of chemicals called potassium-channel openers, is an investigational antiseizure medication in development for patients with focal epilepsy. This treatment is designed to avert seizures by boosting the flow of potassium out of nerves and stopping them from firing.