title: Initial experience in the treatment of inherited mitochondrial disease with EPI-743.
abstract: Inherited mitochondrial respiratory chain disorders are progressive, life-threatening conditions for which there are limited supportive treatment options and no approved drugs. Because of this unmet medical need, as well as the implication of mitochondrial dysfunction as a contributor to more common age-related and neurodegenerative disorders, mitochondrial diseases represent an important therapeutic target. Thirteen children and one adult with genetically-confirmed mitochondrial disease (polymerase γ deficiency, n=4; Leigh syndrome, n=4; MELAS, n=3; mtDNA deletion syndrome, n=2; Friedreich ataxia, n=1) at risk for progressing to end-of-life care within 90 days were treated with EPI-743, a novel para-benzoquinone therapeutic, in a subject controlled, open-label study. Serial measures of safety and efficacy were obtained that included biochemical, neurological, quality-of-life, and brain redox assessments using technetium-99m-hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) radionuclide imaging. Twelve patients treated with EPI-743 have survived; one polymerase γ deficiency patient died after developing pneumonia and one patient with Surf-1 deficiency died after completion of the protocol. Of the 12 survivors, 11 demonstrated clinical improvement, with 3 showing partial relapse, and 10 of the survivors also had an improvement in quality-of-life scores at the end of the 13-week emergency treatment protocol. HMPAO SPECT scans correlated with clinical response; increased regional and whole brain HMPAO uptake was noted in the clinical responders and the one subject who did not respond clinically had decreased regional and whole brain HMPAO uptake. EPI-743 has modified disease progression in >90% of patients in this open-label study as assessed by clinical, quality-of-life, and non-invasive brain imaging parameters. Data obtained herein suggest that EPI-743 may represent a new drug for the treatment of inherited mitochondrial respiratory chain disorders. Prospective controlled trials will be undertaken to substantiate these initial promising observations. Furthermore, HMPAO SPECT imaging may be a valuable tool for the detection of central nervous system redox defects and for monitoring response to treatments directed at modulating abnormal redox.
authors: Department of Pediatrics, Division of Medical Genetics, Lucile Packard Children's Hospital, Stanford University, Stanford, CA 94305-5208, USA. greg.enns@stanford.edu
authors: Gregory M
authors: GM
authors: Enns
authors: Stephen L
authors: SL
authors: Kinsman
authors: Susan L
authors: SL
authors: Perlman
authors: Kenneth M
authors: KM
authors: Spicer
authors: Jose E
authors: JE
authors: Abdenur
authors: Bruce H
authors: BH
authors: Cohen
authors: Akiko
authors: A
authors: Amagata
authors: Adam
authors: A
authors: Barnes
authors: Viktoria
authors: V
authors: Kheifets
authors: William D
authors: WD
authors: Shrader
authors: Martin
authors: M
authors: Thoolen
authors: Francis
authors: F
authors: Blankenberg
authors: Guy
authors: G
authors: Miller
mesh_terms: D000293:Adolescent; D000328:Adult; D016227:Benzoquinones / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation / Q000187:drug effects; D030342:Genetic Diseases, Inborn / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D008297:Male; D028361:Mitochondrial Diseases / Q000000981:diagnostic imaging / Q000188:drug therapy*; D018384:Oxidative Stress; D010091:Oximes; D015899:Tomography, Emission-Computed, Single-Photon; D014451:Ubiquinone / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D016227:Benzoquinones; D010091:Oximes; C068296:hexamethylpropyleneamine oxime; D014451:Ubiquinone; C571746:alpha-tocotrienol quinone