Befiradol (F-13,640; NLX-112) is an experimental drug being studied for the treatment of levodopa-induced dyskinesia. It is a potent and selective 5-HT_1A receptor

full agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...

Pharmacology

In recombinant cell lines expressing human

5-HT1A receptor The serotonin 1A receptor (or 5-HT1A receptor) is a subtype of serotonin receptor, or 5-HT receptor, that binds serotonin, also known as 5-HT, a neurotransmitter. 5-HT1A is expressed in the brain, spleen, and neonatal kidney. It is a G protei ...

s, befiradol exhibits high agonist efficacy for a variety of signal transduction read-outs, including ERK phosphorylation,

G-protein G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. Their act ...

activation,

receptor internalization Receptor-mediated endocytosis (RME), also called clathrin-mediated endocytosis, is a process by which cells absorb metabolites, hormones, proteins – and in some cases viruses – by the inward budding of the plasma membrane (invagination). This ...

and

adenylyl cyclase Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction: :A ...

inhibition. In rat hippocampal membranes it preferentially activates GalphaO proteins. In neurochemical experiments, befiradol activated 5-HT1A autoreceptors in rat dorsal Raphe nucleus as well as 5-HT1A heteroreceptors on pyramidal neurons in the frontal cortex. It has powerful

analgesic An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It ...

and antiallodynic effects comparable to those of high doses of

opioid Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid us ...

painkillers, but with fewer and less prominent side effects, as well as little or no development of

tolerance Tolerance or toleration is the state of tolerating, or putting up with, conditionally. Economics, business, and politics * Toleration Party, a historic political party active in Connecticut * Tolerant Systems, the former name of Veritas Software ...

with repeated use. A

structure–activity relationship The structure–activity relationship (SAR) is the relationship between the chemical structure of a molecule and its biological activity. This idea was first presented by Crum-Brown and Fraser in 1865. The analysis of SAR enables the determination o ...

(SAR) study revealed that replacement of the dihalophenyl moiety by 3- benzothienyl increases maximal

efficacy Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as ''effectiveness'', and it has often been used synonymously, although in pharmacology a pragmatic clinical trial#Efficacy versu ...

from 84% to 124% (K_i=2.7 nM).

History

Befiradol was discovered and developed by Pierre Fabre Médicament, a French pharmaceuticals company. In September 2013, befiradol was out-licensed to Neurolixis, a California-based biotechnology company. Neurolixis announced that it intends to re-purpose befiradol for the treatment of levodopa-induced dyskinesia in

Parkinson's disease 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 ...

. In support of this indication, Neurolixis received several research grants from the

Michael J. Fox Foundation The Michael J. Fox Foundation for Parkinson's Research is dedicated to finding a cure for Parkinson's disease (PD) established in 2000 by Michael J. Fox. It concentrates on funding research and ensuring the development of improved therapies for ...

and preclinical data was published describing the activity of befiradol in animal models of Parkinson's disease. In January 2018, the British charity Parkinson's UK announced that it had awarded Neurolixis a grant to advance development of befiradol up to clinical phase in Parkinson's disease patients. In March 2019, Neurolixis announced that the US

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

(FDA) gave a positive response to Neurolixis' Investigational New Drug (IND) application for NLX-112 to be tested in a Phase 2 clinical study in Parkinson's disease patients with troublesome levodopa-induced dyskinesia. Studies published in 2020 using non-human primate models of Parkinson's disease, ( MPTP-treated marmosets and MPTP-treated macaques), found that befiradol potently reduced Levodopa-induced dyskinesia at oral doses as low as 0.1 to 0.4 mg/kg. On 22 November 2020,

The Sunday Times ''The Sunday Times'' is a British newspaper whose circulation makes it the largest in Britain's quality press market category. It was founded in 1821 as ''The New Observer''. It is published by Times Newspapers Ltd, a subsidiary of News UK, whi ...

reported that the two charities, Parkinson's UK and

, were jointly investing $2 million to support a clinical trial on befiradol in Parkinson's disease patients with troublesome Levodopa-induced dyskinesia, a potentially "life changing" drug. On 23 November 2020, Parkinson's UK and

, confirmed their funding in an official announcement. Neurolixis announced on 30 November 2021 the start of patient recruitment in the clinical trial. The trial is listed on the U.S. National Library of Medicine clinical trials register.

References

{{Serotonergics Analgesics Pyridines Secondary amines Piperidines Benzamides Chlorobenzenes Fluoroarenes

Pharmacology

History

See also

References