Deulinoleate ethyl (also known as di-deuterated ethyl linoleate, di-deuterated linoleic acid ethyl ester, 11,11-d2-ethyl linoleate, or ethyl 11,11-d2-linoleate)[1] is an experimental, orally-bioavailable synthetic deuteratedpolyunsaturated fatty acid (PUFA), a part of reinforced lipids. It is an isotopologue of linoleic acid, an essentialomega-6 PUFA. The deuterated compound, while identical to natural linoleic acid except for the presence of deuterium, is resistant to lipid peroxidation which makes studies of its cell-protective properties worthwhile.
An animated illustration of a chain reaction with slow elements
Deulinoleate ethyl is recognized by cells as identical to normal linoleic acid. But when taken up, it is converted into 13,13-d2-arachidonic acid, a heavy isotope version of arachidonic acid, that gets incorporated into lipid membranes. The deuterated compound resists the non-enzymatic lipid peroxidation (LPO) through isotope effect — a non-antioxidant based mechanism that protects mitochondrial, neuronal and other lipid membranes, thereby greatly reducing the levels of numerous LPO-derived toxic products such as reactive carbonyls.[2][3]
Deulinoleate ethyl inhibits ferroptosis by stopping the autoxidation process through the kinetic isotope effect. The protective effect of D-PUFAs was verified in erastin- and RSL3-induced ferroptosis models, with demonstrated efficacy in various disease models, particularly neurodegenerative disorders and clinical trials of deulinoleate ethyl begun in 2018.[4]
Clinical development
Friedreich's ataxia
A double-blind comparator-controlled Phase I/II clinical trial for Friedreich's ataxia, sponsored by Retrotope and Friedreich's Ataxia Research Alliance, was conducted to determine the safety profile and appropriate dosing for consequent trials.[5] Deulinoleate ethyl was promptly absorbed and was found to be safe and tolerable over 28 days at the maximal dose of 9 g/day. It improved peak workload and peak oxygen consumption in the test group compared to the control group who received the equal doses of normal, non-deuterated ethyl linoleate.[6] Another randomized, double-blind, placebo-controlled clinical study began in 2019.[7]
Infantile neuroaxonal dystrophy
An open-label clinical study for infantile neuroaxonal dystrophy evaluating long-term evaluation of efficacy, safety, tolerability, and pharmacokinetics of deulinoleate ethyl, which, when taken with food, can protect the neuronal cells from degeneration, started in the Summer 2018.[8]
In 2020, the FDA granted orphan drug designation deulinoleate ethyl for the treatment of patients with progressive supranuclear palsy (PSP). PSP is a disease involving modification and dysfunction of tau protein; mechanism of action of deulinoleate ethyl both lowers lipid peroxidation and prevents mitochondrial cell death of neurons which is associated with disease onset and progression.[11]
Preclinical research
Alzheimer's disease
Deulinoleate ethyl has been shown to be effective in a model of Alzheimer's disease in mice.[12]
^Clinical trial number NCT02445794 for "A First in Human Study of RT001 in Patients With Friedreich's Ataxia" at ClinicalTrials.gov
^Zesiewicz T, Heerinckx F, De Jager R, Omidvar O, Kilpatrick M, Shaw J, Shchepinov MS (July 2018). "Randomized, clinical trial of RT001: Early signals of efficacy in Friedreich's ataxia". Movement Disorders. 33 (6): 1000–1005. doi:10.1002/mds.27353. PMID29624723. S2CID4664990.
^Clinical trial number NCT04102501 for "A Study to Assess Efficacy, Long Term Safety and Tolerability of RT001 in Subjects With Friedreich's Ataxia" at ClinicalTrials.gov
^Clinical trial number NCT03570931 for "A Study to Assess Efficacy and Safety of RT001 in Subjects With Infantile Neuroaxonal Dystrophy" at ClinicalTrials.gov
