US007 119118B2
`
`(12) United States Patent
`Peet et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,119,118 B2
`Oct. 10, 2006
`
`(54) HIGHLY PURIFIED ETHYL EPA AND
`OTHER EPA DERVATIVES FOR
`TREATMENT OF HUNTINGTON'S DISEASE
`
`(75) Inventors: Malcolm Peet, Sheffield (GB); Krishna
`S Vaddadi, Melbourne (AU)
`(73) Assignee: Laxdale Limited, Stirling (GB)
`(*) Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 364 days.
`(21) Appl. No.: 10/191,430
`(22) Filed:
`Jul. 10, 2002
`(65)
`Prior Publication Data
`US 20O2/O193439 A1
`Dec. 19, 2002
`
`Related U.S. Application Data
`(60) Continuation of application No. 10/014.603, filed on
`Dec. 14, 2001, now Pat. No. 6,689,812, which is a
`division of application No. 09/492.741, filed on Jan.
`27, 2000, now Pat. No. 6,384,077.
`Foreign Application Priority Data
`(30)
`Jan. 27, 1999
`(GB) ................................. 99.01809.5
`
`(51) Int. Cl.
`(2006.01)
`A6 IK 3L/202
`(52) U.S. Cl. ...................................................... 514/560
`(58) Field of Classification Search ................. 514/560
`See application file for complete search history.
`References Cited
`
`(56)
`
`U.S. PATENT DOCUMENTS
`
`5,252.333 A 10, 1993 Horrobin .................... 424/422
`5,589,508 A 12, 1996 Schlotzer et al. ........... 514,560
`5,837,731 A * 11/1998 Vaddadi ...................... 514,560
`5,840,944 A 11/1998 Furihata et al. .
`... 554,175
`6,555,700 B1 * 4/2003 Horrobin et al. ........... 554,227
`FOREIGN PATENT DOCUMENTS
`
`
`
`EP
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`EP
`GB
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`JP
`WO
`
`2, 1989
`O3O2482 A2
`O 460 917. A 12/1991
`O 606 012. A
`T 1994
`O 610 506 A
`8, 1994
`214.8713 A
`6, 1985
`2 229 363 A
`9, 1990
`O4 182426 A
`6, 1992
`WO 97 397.59 A 10, 1997
`
`WO
`WO
`
`WO98, 16216
`WO99 29316 A
`
`4f1998
`6, 1999
`
`OTHER PUBLICATIONS
`Malcolm Peet et al. Phospholipid Spectrum Disorder in Psychiatry
`pp. 1-19, 1999.
`Brian E. Leonard, Fundamentals of Psychopharmacology, pp. 186
`187, 1997.
`Diagnostic and Statistical Manual of Mental Disorders, 4" Ed.,
`published by the American Psychiatric Assoc., p. 285 (1995).
`Martin A. Samuels, M.D. et al. Office Practice of Neurology,
`Chapter 122, Huntington's Disease, pp. 654-655 (1996).
`S. Leucht et al. Schizophrenia Research, vol. 35. “Efficacy and
`extrapyramidal side-effects . . .
`. pp. 51-68, 1999.
`Nina Willumsen et al. Biochimica et Biophysica Acta, vol. 1369,
`“On the effect of 2-deuterium- . .
`.
`. pp. 193-203, 1998.
`E. Mayatepek et al. The Lancet, vol. 352, "Leukotriene C4-synthe
`sis deficiency . . .
`. pp. 1514-1517, Nov. 7, 1998.
`Atsushi Yamashita et al. J. Biochem... vol. 122, No. 1. “Acyl
`transferases and Transacylases . . .
`. pp. 1-16, 1997.
`Yang Cao et al. Genomics, vol. 49. “Cloning. Expression, and
`Chromosomal Localization . . .
`. pp. 327-331, 1998.
`Monica Piccini et al. Genomics, vol. 47, "FACL4, a New Gene
`En-coding Long-Chain Acyl-CoA. . .
`. pp. 350-358, 1998.
`Michael J. Finnen et al. Biochemical Society Trans., “Purifi-cation
`and characterisation . . .
`. p. 19, 1991.
`Andrew L. Stoll et al. Arch. Gen. Psychiatry, vol. 56, "Omega 3
`Fatty Acids in Bipolar Disorder', pp. 407-412, May 1999.
`B. Puri et al. Archives of General Psychiatry, No. 55, "Sustain-ed
`remission of positive and . . .
`. pp. 188-189, 1998.
`Stephen T. Warren, Science, vol. 271, “The Expanding World of
`Trinucleotide Repeats”, pp. 1374-1375. Mar. 8, 1996.
`Victor O. Ona et al. NATURE. vol. 399, "Inhibition of caspase-1
`slows disease progression .
`. .
`. pp. 263-267. May 20, 1999.
`Philippe Dijan et al. Proc. Natl. Acad. Sci., vol. 93, "Codon repeats
`in genes associated . . .
`. pp. 417-421, Jan. 1996.
`M. Flint Beal, MD, Annals of Neurology, vol. 38, No. 3, "Aging,
`Energy, and Oxidative Stress in . . .
`. pp. 357-366, Sep. 1995.
`(Continued)
`Primary Examiner Phyllis G. Spivack
`(74) Attorney, Agent, or Firm—Jacobson Holman PLLC
`(57)
`ABSTRACT
`A pharmaceutical preparation comprising EPA in an appro
`priately assimilable form where of all the fatty acids present
`in the preparation at least 90%, and preferably at least 95%,
`is in the form of EPA and where less than 5%, and preferably
`less than 3%, is in the form of DHA is provided for the
`treatment of a psychiatric or central nervous disorder. The
`preparation may be administered with conventional drugs to
`treat psychiatric or central nervous disorders to improve
`their efficacy or reduce their side effects.
`
`20 Claims, 3 Drawing Sheets
`
`Hikma Pharmaceuticals
`
`IPR2022-00215
`
`Ex. 1042, p. 1 of 15
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`

`

`US 7,119,118 B2
`Page 2
`
`OTHER PUBLICATIONS
`S. L. McElroy et al., “Clozapine in the Treatment of Psychotic
`Mood Disorders, Schizoaffective Disorder, and Schizophrenia'.
`Journal of Clinical Psychiatry, vol. 52, No. 10, Oct. 1991, pp.
`411-414.
`K.L. Black et al., “Effect of intravenous eicosapentaenoic acid on
`cerebral blood flow, edema, and brain prostaglandins in ischemic
`gerbils'. Prostaglandins (1984), 28(4), pp. 545-546.
`M. Sato et al., “General Pharmacological Studies on 58 11 14 17
`Eicosapentaenoic Acid Ethyl Ester EPA-E'. Folia Pharmacol JPN,
`(1989) 94(1), 35-48.
`N. Madhavi et al., “Effect of n-6 and n-3 fatty acids on the survival
`of Vincristine sensitive and resistant human cervical carcinoma cells
`in vitro'. Cancer Letters, vol. 84, No. 1, 1994, pp. 31-41.
`Katsuya Yamazaki et al., “Changes in fatty acid composition in rat
`blood and organs after infusion of eicosapentaenoic acid ethyl
`ester, Biochim. Biophys. ACTA (1992), 1128(1), 35-43.
`
`Effects of highly purified
`Toshihiro Yoshimura et al.
`eicosapentaenoic acid on plasma beta thromboglobulin level and
`vascular reactivity to angiotensin II, Artery (1987) 14(5) pp. 295
`303.
`emulsified
`of
`“Infusion
`al.,
`et
`Urakaze
`Masaharu
`trieicosapentaenoylglycerol into rabbits. The effects on platelet
`aggregation, polymorphonuclear leukocyte adhesion, and fatty acid
`composition in plasma and platelet phospholpids'. Thromb. Res.
`(1986) 44(5), pp. 673-682.
`Ikuyoshi Watanabe et al., “Usefulness of EPA-E (eicosapentaenoic
`acid ethyl ester) in preventing neointimal formation after vascular
`injury”, Kokyu to Junkan (1994), 42(7), pp. 673-677.
`S. Shah et al., “Eicosapentaenoic Acid (EPA) as an Adjunct in the
`Treatment of Schizophrenia'. Schizophrenia Research, vol. 29, No.
`1/02, Jan. 1998.
`* cited by examiner
`
`Hikma Pharmaceuticals
`
`IPR2022-00215
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`Ex. 1042, p. 2 of 15
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`

`

`U.S. Patent
`
`Oct. 10, 2006
`
`Sheet 1 of 3
`
`US 7,119,118 B2
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`Figure 1. The synthesis of eicosapentaenoic acid from alpha-linolenic acid
`
`18:31-3
`
`Alpha-linolenic acid
`
`Delta-6-desaturation
`
`8:4n-3
`
`Stearidonic acid
`
`Elongation
`
`20:4-3
`
`Eicosatetraenoic acid, n-3
`
`20:5n-3
`
`Eicosapentaenoic acid
`
`Hikma Pharmaceuticals
`
`IPR2022-00215
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`Ex. 1042, p. 3 of 15
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`

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`Hikma Pharmaceuticals
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`IPR2022-00215
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`Ex. 1042, p. 4 of 15
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`

`

`U.S. Patent
`
`US 7,119,118 B2
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`
`
`
`
`
`
`NOILOTICISN\/>| L. TV/N5)|S CII d'ITIOHCHSOHd
`
`— »
`
`Hikma Pharmaceuticals
`
`IPR2022-00215
`
`Ex. 1042, p. 5 of 15
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`

`

`US 7,119,118 B2
`
`1.
`HIGHLY PURIFED ETHYL EPA AND
`OTHER EPA DERVATIVES FOR
`TREATMENT OF HUNTINGTON'S DISEASE
`
`2
`98/16216 disclosed the use of EPA and its derivatives for the
`treatment of psychiatric disorders.
`The present invention provides a pharmaceutical prepa
`ration comprising EPA in an appropriately assimilable form
`where of all the fatty acids present in the preparation at least
`90%, and preferably at least 95%, is in the form of EPA and
`where less than 5%, and preferably less than 3%, is in the
`form of docosahexaenoic acid. Such preparations are for the
`treatment of any disorder except peripheral vascular disease
`and hyper-triglyceridaemia.
`Preferably, among the other fatty acids present there are
`less than 5%, and preferably less than 3%, of each of AA or
`DPA-n-3, individually. The same preferably applies for any
`other fatty acids which might compete with the EPA.
`It is preferred that the aggregate DHA. AA and/or DPA
`n-3 content is less than 10%, of the total fatty acids present,
`and preferably less than 5%.
`The EPA may be in the form of ethyl-EPA, lithium EPA,
`mono-, di- or triglyceride EPA or any other ester or salt of
`EPA, or the free acid form of EPA. The EPA may also be in
`the form of a 2-substituted derivative or other derivative
`which slows down its rate of oxidation but does not other
`wise change its biological action on psychiatric or brain
`disorders to any substantial degree (N. Willumsen et al.,
`Biochimica Biophysica Acta, 1998, 1369: 193–203).
`Such pharmaceutical preparations may be used for the
`treatment of a psychiatric or central nervous system disor
`der, including: Schizophrenia, Schizoaffective disorder or a
`Schizotypal disorder, depression or manic-depression (bipo
`lar disorder); anxiety or panic disorder or Social phobia, or
`a sleep disorder or an attention deficit, conduct, hyperactiv
`ity or personality disorder; autism; Alzheimer's disease,
`vascular dementia or another dementia, including multi
`infarct dementia, Lewy body disease and diseases attribut
`able to prion disorders: Parkinson's disease, or other motor
`system disorder, multiple Sclerosis; stroke; epilepsy; and
`Huntington's disease or any other neuro-degenerative dis
`order.
`The present invention further provides formulations for is
`use in psychiatric and neurological disorders in which a drug
`which acts primarily on neurotransmitter metabolism or
`receptors is prepared for co-administration with a pharma
`ceutical preparation according to the first aspect of the
`invention, as well as pharmaceutical formulations compris
`ing a preparation according to the first aspect of the inven
`tion together with a drug which acts primarily on neurotrans
`mitter metabolism or receptors. The conventional drug may
`administered in conventional dosage, and the EPA formu
`lations according to the first aspect of the invention admin
`istered to the patient separately. The conventional drug may
`be combined with the EPA preparations of the first aspect of
`the invention in a combination formulation, or the two may
`be provided in separate individual formulations but in a
`combination pack.
`The EPA-containing preparations of the present invention
`may be administered with any drug known to have an effect
`on the treatment of psychiatric or central nervous system
`disorders to improve the efficacy of the drug or reduce its
`side effects.
`Suitable drugs for co-administration with the EPA prepa
`rations of the first aspect of the invention are clozapine; and
`any one of the class of typical or atypical neuroleptics,
`including chlorpromazine, haloperidol, risperidone, olanza
`pine, sertindole, Ziprasidone, Zotepine or amisulpiride. Oth
`ers are mentioned below.
`The present invention still further provides a method of
`treating or preventing the side effects of a drug used in
`
`10
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`30
`
`This is a Continuation of application Ser. No. 10/014,603
`filed Dec. 14, 2001 now U.S. Pat. No. 6,689,812, which is
`a Divisional of U.S. Ser. No. 09/492,741, filed Jan. 27, 2000
`and issued as U.S. Pat. No. 6,384,077 on May 7, 2002.
`Even though many new drugs have been discovered over
`the past twenty years, psychiatric disorders are still rela
`tively poorly treated. With most psychiatric illnesses, drug
`treatments do not treat all patients Successfully. This is true
`of Schizophrenia, Schizoaffective and Schizotypal disorders,
`bipolar disorder (manic-depression), unipolar depression,
`dementias, panic attacks, anxiety, sleep disorders, attention,
`hyperactivity and conduct disorders, autism, personality
`disorders, and all other psychiatric conditions. For example,
`in depression, standard drugs achieve a 50% reduction in
`standard depression scores in about two thirds of patients:
`the others do not respond. In Schizophrenia, the average
`improvements are only of the order of 20–30% (S Leucht et
`al, Schizophrenia Research 1999:35:51–68) although indi
`vidual patients may do much better than this.
`The same is true of neurological disorders like Alzhe
`imer's disease and other dementias, Parkinson's disease,
`multiple Sclerosis, stroke, epilepsy and Huntington's dis
`ease. Again, many patients fail to respond to existing treat
`ments, or respond only to a limited degree. In none of these
`conditions do existing drugs reliably produce a complete
`remission of symptoms. There is therefore a great need for
`new treatments, particularly ones which have novel mecha
`nisms of action.
`In PCT filing WO98/16216 attention was drawn to the
`value of a particular fatty acid, eicosapentaenoic acid (EPA),
`and its derivatives, in the treatment of Schizophrenia, depres
`sion and dementias. EPA is a highly unsaturated fatty acid
`which can be derived from the dietary essential fatty acid,
`O-linolenic acid by a series of three reactions (FIG. 1). EPA
`is a fatty acid containing 20 carbon atoms and 5 double
`40
`bonds, all in the cis-configuration. The double bonds are
`located at the 5, 8, 11, 14 and 17 positions and the full
`chemical name is therefore all cis (or all Z) 5, 8, 11, 14,
`17-eicosapentaenoic acid (or sometimes icosapentaenoic
`acid). The abbreviation which is always used is EPA. EPA is
`45
`one of the highly unsaturated fatty acids, the main types of
`which are shown in FIG. 2. The reactions which convert
`alpha-linolenic acid to EPA are slow in humans and only a
`very Small proportion of dietary C-linolenic acid is con
`verted to EPA. EPA is also found in marine micro-organisms
`50
`and, via the food chain, makes up between 3% and 30% of
`natural marine oils derived from oily fish and marine mam
`mals. EPA is found linked to many different chemical
`structures. It can be found in the form of phospholipids, tri,
`di- and monoglycerides, amides, esters of many different
`55
`types, salts and other compounds. In each case the EPA
`moiety can normally be split from the complex molecule to
`give the free acid form which can then be linked again to
`other complex molecules.
`As described in PCT filing WO 98/16216 it was unex
`pectedly found that an oil enriched in EPA was of value in
`treating Schizophrenia, while an oil enriched in the closely
`related fatty acid, docosahexaenoic acid (DHA), was not.
`This was surprising because DHA is found in large amounts
`in human brain whereas EPA is found only in trace quanti
`ties. It was therefore anticipated that DHA would be effec
`tive but EPA would not. In fact the opposite was found. WO
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`3
`treating psychiatric or neurological disorders by administra
`tion of the drug and a pharmaceutical preparation according
`to the first aspect of the present invention.
`It is important in treatment of psychiatric disorders to use
`pure or nearly pure EPA and EPA derivatives. It is a
`Surprising conclusion that DHA and related fatty acids may
`not only be ineffective but may actually reduce the efficacy
`of EPA and its derivatives.
`Phospholipids are the main components of nerve cell
`membranes. In nerve cells the middle carbon atom of
`phospholipids, known as Sn2, is usually attached to a highly
`unsaturated fatty acid (HUFA) such as DHA, arachidonic
`acid (AA), and sometimes EPA. HUFAs are fatty acids
`containing 18–26 carbon atoms and three or more double
`bonds. When nerve cells are activated, for example by
`dopamine or serotonin, the activity of a group of enzymes
`collectively known as phospholipase A (PLA) is fre
`quently increased. PLA releases the HUFA from the Sn2
`position, giving a free molecule of HUFA and a molecule of
`what is known as a lysophospholipid (LyPL) (a phospholipid
`without a fatty acid attached to the Sn2 position) (FIG. 3).
`Both of these molecules can be highly active cell signalling
`agents themselves, and can change cell function in a number
`of different ways. In addition, the HUFA can be converted to
`prostaglandins, leukotrienes, hydroxy acids and a whole
`range of short-lived molecules which regulate neuronal
`function. For example, one of these molecules derived from
`arachidonic acid, leukotriene C4, seems to be absolutely
`required for normal nerve cell growth and development (E
`Mayatepek and B Flock, Leukotriene C4-synthesis defi
`ciency: a new inborn error of metabolism linked to a fatal
`developmental syndrome Lancet 1998; 352: 1514–7).
`If cell function is to be normal, it is important that this
`activation should be temporary and should be terminated by
`removing the free HUFA and the LyPL. Otherwise mem
`35
`brane damage may result because the LyPL can be destruc
`tive. Furthermore the free HUFAs are easily oxidised to
`highly active free radicals which can do great damage. There
`is an emerging consensus that such membrane damage is a
`fundamental pathological basis for many neurodegenerative
`40
`disorders, including Alzheimer's disease and other demen
`tias, Parkinson's disease, stroke, Huntington's disease, all
`types of ischaemic damage, and multiple Sclerosis. A range
`of initiating causative factors may all cause damage by the
`same common route. Phospholipid breakdown to LyPLs and
`free HUFAs may also be important in epilepsy.
`The signal transduction processes involving HUFAS and
`LyPLS are terminated in most cases by a two sequence
`reaction. First, the HUFA is linked to coenzyme Aby a group
`of enzymes known as fatty acid coenzyme A ligases (FA
`50
`CLS). These enzymes are also known as acyl-CoA syn
`thetases. The HUFA-coenzyme A derivative is then linked to
`the LyPL by a group of enzymes known as acyl CoA:
`lysophospholipid acyltransferases (ACLATs) which liberate
`coenzyme A in the process (A Yamashita et al. Acyltrans
`ferases and transacylases involved in fatty acid remodelling
`of phospholipids and metabolism of bioactive lipids in
`mammalian cells. J Biochem 122: 1–16, 1997). This
`sequence thus removes from the nerve cell the HUFAs and
`the LyPLs and brings to an end the events associated with
`signal transduction, so preparing the neuron for the next
`stimulus (FIG. 3).
`There is now a substantial amount of evidence which
`demonstrates that in the three major psychotic mental ill
`nesses there is increased activity of one or more of the
`phospholipase group of enzymes and particularly in one or
`more of the PLA group. These three illnesses are schizo
`
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`US 7,119,118 B2
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`4
`phrenia, bipolar disorder and major depression: the three
`disorders are often found together in the same families, and
`often have overlapping ranges of symptoms. It has long been
`thought that at least part of their biochemical basis is
`common to all three disorders and it is possible that the
`PLA abnormality constitutes that common factor. In
`Schizophrenia, there are increasing circulating levels of
`PLA in the blood. In bipolar disorder, lithium, which is the
`main established treatment, has been shown to inhibit the
`activity of PLA. In major depression, there is depletion of
`HUFAs of the n-3 series from membranes, coupled with
`activation of inflammatory responses which occurs with
`enhanced activity of PLA. Each of those illnesses, however,
`involves more than one biochemical abnormality: while a
`PLA, or related phospholipase abnormality may be common
`to all three, the other abnormalities are probably specific to
`each disease.
`In schizophrenia, it has recently been discovered that
`there is a second abnormality in the fatty acid cycle. This is
`a deficit in function of FACL-4, the enzyme which links
`HUFAs to coenzyme A in human brain (Y Cao et al.
`Cloning, expression and chromosomal localization of
`human long-chain fatty acid-CoA ligase 4 (FACL4) Genom
`ics 1998; 49:327–330). It is known that there is a defect in
`the incorporation of HUFAs into phospholipids in is schizo
`phrenia but the precise enzyme has not been known. How
`ever, FACL-4 is found in brain, is specific for HUFAs, and
`when absent produces both brain abnormalities and also
`minor physical abnormalities such as a high arched palate
`which are typical of patients with schizophrenia (M Piccini
`et al., FACL-4, a new gene encoding long-chain acyl-CoA
`synthetase 4, is deleted in a family with Alport Syndrome,
`elliptocytosis and mental retardation. Genomics 1998:47:
`350–358). It is the combined presence of both the enzyme
`abnormalities which produces the disease.
`The second or other abnormalities in bipolar disorder and
`in major depression are not yet known. Another phospholi
`pase, PLC, which acts at the Sng position to liberate inositol
`phosphates and diacylglycerol may be involved in bipolar
`disorder. Both of these molecules, like LyPL and HUFAs,
`are involved in cell signalling: overactivation of both PLC
`and PLA is likely to be related to bipolar disorder.
`In the neurodegenerative conditions there appears to be an
`uncontrolled activation of membrane degrading enzymes
`like phospholipases, coupled with increased formation of
`free radicals associated with the oxidation of HUFAs and the
`membrane damage produced by LyPL. This type of phe
`nomenon, with membrane damage associated with excess
`phospholipase activity, has been well described by many
`investigators in Alzheimer's disease and other dementias, in
`multiple Sclerosis, in Stroke and other brain disorders caused
`by ischaemia or injury, in Parkinson's disease, in epilepsy
`and in Huntington's disease. In attention deficit disorder,
`also known as hyperactivity, there are deficits in the blood
`of the highly unsaturated fatty acids which can be acted upon
`by phospholipases.
`In all of these situations, therefore, there is some evidence
`of increased phospholipase activity and signal transduction
`activity which may not be terminated in a normal way. Thus
`the phospholipases, FACLS and acyl-transferases present
`new targets for drug action. Our observation that EPA
`enriched materials are beneficial in psychiatric disorders
`may therefore be explained in several ways:
`EPA is known to inhibit phospholipase A (MJ Finnen &
`CR Lovell, Biochem Soc Transactions, 1991:19:915) and so
`will help to down regulate the initial activation process.
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`Hikma Pharmaceuticals
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`IPR2022-00215
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`Interestingly, in this assay system, the related fatty acid
`docosahexaenoic acid (DHA) had no effect.
`EPA has an unusually high affinity for the human brain
`enzyme FACL-4 (YCao et al., 1998 see above). Usually with
`enzymes which act on HUFAs, the activities with HUFAs
`like EPA, DHA and AA are similar, or very frequently, DHA
`and AA are more active than EPA. With FACL-4, however,
`activity for AA was more than twice as great as for DHA.
`whereas that for EPA was 50% greater than for AA (Y Cao
`et al., 1998). This means that EPA will more readily than
`other HUFAs enter the cycle, form an EPA-CoA derivative,
`link to LyPL and so terminate the activity of free LyPL. Thus
`EPA will, more effectively than other HUFAs, stop the
`activation once it has started.
`Because EPA will compete with AA for incorporation into
`the Sn2 position of phospholipids, EPA will also reduce the
`amount of AA incorporated into that position. This is likely
`to be particularly important in depression, where AA levels
`are relatively or absolutely abnormally high.
`EPA itself is a HUFA which can be converted to desirable
`compounds like prostaglandin I (PGI) and prostaglandin
`E. (PGE) which have a range of anti-inflammatory and
`antithrombotic actions which may be particularly useful in
`neurodegenerative disorders and in depression. The com
`pounds derived from EPA appear to be less potentially
`25
`harmful than the equivalent compounds derived from AA.
`Replacement of AA by EPA is therefore likely to be of
`particular value in all the neurodegenerative disorders
`described above, where at least part of the damage is
`attributable to overactive phospholipases which release AA
`30
`which can then be converted to pro-inflammatory com
`pounds.
`The purification of EPA is difficult and complex. Because
`its five double bonds must all be in the right positions in the
`carbon chain and must all be in the cis configuration, EPA is
`difficult to synthesize. In nature EPA is almost always found
`mixed with other fatty acids in the forms of triglycerides and
`phospholipids. The principles of purification of EPA are well
`known to those skilled in the art and include low temperature
`crystallisation, urea fractionation, lithium crystallisation,
`fractional distillation, high pressure liquid chromatography,
`Supercritical carbon dioxide chromatography and various
`other forms of chromatography using silica gels and other
`column packings. The application of these known tech
`niques has been difficult to apply in practice on a large scale
`and only recently has pure EPA (more than 90% pure and
`preferably more than 95% pure) become available for testing
`in psychiatric and CNS disorders. In one version of the
`purification process, natural fish oil triglycerides rich in EPA
`are saponified and the fatty acids converted to the ethyl ester
`50
`form. A preparation enriched in ethyl EPA is then prepared
`by molecular distillation with collection of the appropriate
`fraction. This fraction is then converted to a preparation
`containing over 80% of ethyl EPA by urea precipitation. The
`final preparation of more than 96% pure ethyl EPA is then
`achieved by either silica gel chromatography or high pres
`Sure liquid chromatography.
`Conventionally, most studies on the uses of EPA and
`related fatty acids have used materials partially enriched in
`EPA but also containing substantial amounts of other fatty
`acids, especially docosahexaenoic acid (DHA) which is
`found alongside EPA in most natural oils. The fatty acids
`have usually been in the triglyceride or ethyl ester forms,
`and occasionally in the free acid and phospholipid forms.
`Docosapentaenoic acid (DPA n-3) is also a common com
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`ponent of such materials. The new understanding of possible
`mechanisms of action of EPA which we have developed has,
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`however, led to the realisation that the purer is the EPA the
`better is likely to be the activity. This is not just a question
`of dose, although that is indeed a valuable aspect of the
`application of pure EPA From the point of view of a patient,
`particularly a mentally disturbed patient, it is obviously
`better to give, say, 1 g of EPA as a 95% pure preparation
`than, say, 5g of a 19% pure preparation providing the same
`total amount of EPA. The patient is much more likely to
`comply with the lower volumes required with the highly
`purified compound.
`More importantly, other fatty acids such as AA, DPAn-3,
`and DHA, which are relatively similar in structure to EPA,
`but do not share the same spectrum of biological activity,
`compete with EPA for binding to the active sites of all the
`relevant enzymes. Thus these other fatty acids will compete
`with EPA for occupation of these active sites and reduce its
`activity. The purer the preparation of EPA the more likely is
`it to occupy the relevant active binding sites, and the more
`likely is it to be able to have desirable biological effects.
`Our attention was unexpectedly drawn to the importance
`of highly purified EPA by our experience with a patient, a
`depressed women aged 35 years. She had had a long history
`of depression with Hamilton Depression Rating Scale scores
`ranging from 15 to 25. Trials of several different antidepres
`sants, including traditional tricyclic compounds and newer
`selective serotonin reuptake inhibitors had failed to have an
`impact. Because of evidence of the importance of EPA in
`depression she was given a three months trial of 4 g/day of
`an EPA enriched fish oil containing 25% of EPA, together
`with 8% of DHA and 10% of other highly unsaturated fatty
`acids. At the start of this trial she had a Hamilton score in the
`20–22 range and at the end a Hamilton score in the 16–18
`range, a small but not very important improvement. She
`continued the EPA-rich oil for a further two months without
`any further change. A 96% pure preparation of ethyl-EPA
`with less than 3% DHA then became available to me and it
`was suggested that the woman should Switch from taking 4
`g/day of the 25% EPA preparation to 1 g/day of the 96%
`preparation. We expected that this would be more conve
`nient but did not expect any clinical improvement because
`the EPA daily dose remained unchanged. However, surpris
`ingly, after about 3–4 weeks she began to experience a major
`improvement with Hamilton scores falling below 6 for the
`first time for several years. As a result of this, and of thinking
`about the evidence relating to the binding of EPA to FACL-4
`and presumably to other proteins, we came to the conclusion
`that it was important for clinical efficacy to administer EPA
`in a highly purified form for maximum clinical effectiveness.
`Surprisingly, the same daily dose of EPA in a purified form
`seems considerably more effective than that dose when
`mixed with other fatty acids which may compete with EPA
`for binding to the relevant sites of action.
`This initial experience has now been confirmed by many
`other case reports in a range of psychiatric disorders. Some
`examples of the observations made include the following:
`Schizophrenia: A patient with a ten-year history had been
`well controlled by taking 16x0.5 g capsules a day of fish oil
`containing 24% of EPA and 8% of DHA. This provided
`around 1.9 g/day of EPA and 0.6 g/day of DHA. He was not
`taking other antipsychotic drugs. However, he did not like
`taking the high doses of fish oils and tried to reduce the dose.
`However, when he did this the symptoms returned and it was
`concluded that he had to take around 2 g/day of EPA to
`remain well. When the purified ethyl-EPA became available,
`he was Switched to 4x0.5 g capsules, also providing around
`2 g/day. This controlled his symptoms very well. He there
`fore dropped the dose to 1 g/day. Unlike the previous
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`Hikma Pharmaceuticals
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`IPR2022-00215
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`Ex. 1042, p. 8 of 15
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`US 7,119,118 B2
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`situation with the mixed fish oil providing 1.9 g/day of EPA
`and 0.6 g/day of DHA, reducing the ethyl-EPA dose to 1
`g/day did not lead to a recurrence of symptoms. 1 g/day in
`pure form therefore appeared as effective and possibly more
`effective than 1.9 g per day of EPA when mixed with DHA
`and other fatty acids.
`Bipolar disorder: Bipolar disorder is a condition in which
`either a depressive or a manic state is episodic, or in which
`depressive or manic States alternate. The standard treatments
`are lithium or valproate derivatives, or the antipsychotic
`neuroleptic drugs which are particularly used to control the
`manic states. Standard antidepressants are sometimes used
`but they have to be applied with caution because there is a
`risk that they may precipitate a manic state.
`Very high doses (9–10 g/day) of mixed EPA and DHA
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`have been reported to be helpful in managing bipolar
`patients, improving depression and reducing the risk of
`relapse into either a depressive or a manic episode (A Stoll
`et al. Omega-3 fatty acids in bipolar disorder. Archives of
`General Psychiatry, 1999; 56: 407-412). Prior to the avail
`ability of the pure ethyl-EPA, five patients with bipolar
`disorder, whose condition was only partially controlled by
`lithium with intermittent neuroleptics to control the manic
`episodes, were given 10–20 g/day of a fish oil containing
`18% of EPA and 12% of DHA. This provided 1.8-3.6 g of
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`EPA and 1.2-2.4 g of DHA per day. On this treatment the
`patients were less depressed, and less prone to mood Swings,
`as indicated by following their clinical course for over a
`year. They were, however, far from completely normal.
`When the pure ethyl-EPA became available, they were
`switched from the fish oil to the pure EPA at a dose of 2
`g/day in the form of four 0.5 g soft gelatin capsules. In each
`case their clinical condition improved considerably. Their
`depressions became substantially better and they showed
`less tendency to mood Swing. In particular they all noted an
`improvement in something which is difficult to measure by
`conventional psychiatric rating scales. This is a sense of
`inner tension or dysphoria, a state which is associated with
`the illness, but which may be exaggerated or changed by
`antipsychotic drugs to a state of confused tension, some
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`times described as a sense of the brain being replaced by
`cotton wool, and a difficulty of thinking clearly in a straight
`line. Remarkably, the patients reported that this sense of
`dysphoria, tension a