Note: Descriptions are shown in the official language in which they were submitted.
WO96/01645 PCT/GB95/01619
21 9~67~
USE OF MURAMYL PEPTIDE COMPOUNDS _ =
The present invention relates to the treatment of
inflammatory dermatological conditions and in particular
to the treatment of psoriasis.
Psoriasis is a non-infective, usually chronic
;nfl. -tory skin disease occurring in about 2~ of the
population. It has a number of clinical manifestations,
the most common of which is raised, red, rongh~n~
plaques covered by silvery scales. The nails are
involved in about 50~ of cases, and arthritic involvement
may occur. The ~t~rnAl changes in the skin are
associated with histological changes in the disposition
of the epidermis, and vascularisation of sub-epidermal
tissues. Infiltration of lymphocytes commonly occurs.
The occurrence of psoriasis results from a combination of
envi,l ~1 and genetic factors. Numerous studies have
demonstrated a range of changes in functionality of the
epidermis and immune system of psoriatics, but no
comprehensive theory yet exists which can accounts for
all the observed abnormalities.
Current therapy for psoriasis can be topical (;n~ln~ing
steroids, coal tar, dithranol, vitamin ~3 derivatives)
oral (including retinoids, methotrexate, cyclosporine) or
phototherapy (W13 alone, or W A with psoralen).
Unfortunately, the more effective preparations (eg.
steroids, methotrexate, cyclosporine) have the potential
to cause severe side effects. The less potent,
palliative preparations, which tend to be topical,
although being less dangerous, are frequently messy and
inconvenient to use.
WO96101645 2 1 9 4 6 7 8 PCTIGB95/01619
.
It is therefore evident that an effective, safe, oral
treatment for psoriasis i9 a very desirable medication
and would have extreme utility.
It has now been discovered that various muramyl peptide
derivatives are useful in the treatment of psoriasis.
It has long been known that non-specific 8t; l~tinn of
the immune system can be brought about by exposure to
bacteria, ~or components extracted from bacterial cell
walls. The specific .~ _ ~ntc responsible for this
activity were identified as sugar-cnnt~;n;ng peptides of
the cell wall, and further biochemical analysis of the
peptide identified then as the peptidoglycan ~ ~nt of
the cell wall. The smallest effective synthetic molecule
was found to be an N-acetylmuramyl-~-alanyl-D-
isoglutamine (Merser et al, Biochem. Piophys. Pes. Comm.
66 1316 (1975)). The ability of this ~ ~ ' lnow
fre~uently referred to as ~prototype muramyl dipeptide"
or "prototype MDP") to protect mice against bacterial
infection_ (~lebsiella pn~n~nni~) has been described
(Chedid et al, Proc. Nat'l. Acad. Sci. USA, 74 2089
(1977)).
Subseauently, a wide variety of analogues of prototype
muramyl dipeptide were synthesised, some of which have
been proposed as treatments for the restnr~t;nn of immune
function or the non-specific st;~nlst;nn of the immune
system. These analogues, and prototype MDP itself, are
muramyl peptide compounds.
Various authors have dealt with the use of muramyl
peptides and analogues thereof as adjuvants, including
Azuma et al (Adv. Exp. Med. i3iol. 319, 253-263 tl992)),
WO96/01645 2 1~ ~ 6 7 8 r, ~ ~1619
.
who teach that MDPs are effective for use as
1 n~juvants for the potentiation of antiyenicity of
recombinant or component vaccines.
Allison et al (Semin. Immunol. 2(5) 369-374 ~1990)) teach
that an adjuvant formulation consisting of a synthetic
MDP analogue in a squalane-Pluronic polymer ~mlllcinn
elicits cell-mediated immunity and ~nt;ho~;es Of
protective isotypes and ~nr,~~ntq responses to various
antigens.
Burke (Rev. Infect. Dis., 13, Suppl. 11, pS906-911, Nov-
Dec 1991) teaches that MTP-PE was found to be
particularly useful as an adjuvant with a Herpes simplex
virus subunit vaccine.
Allison et al (~ol. Immunol., 28~3) 279-284 (1991))
relates to the use of MDP analogues with antigens to
elicit cell mediated immunity in influenza, hepatitis B
virus, herpes simplex virus, lentivirus and tumour
vaccines.
Muramyl peptides have also been proposed for use as anti
viral agents (Ikeda et al, Anti~iral ~es 5:207-15 (1985))
and in the treatment of cancers (Phillips NC and Tsao, M-
S, Cancer Immunol Immunother. 33:85-90 (1991)).
In the t~srh;nr of these documents, little is disclosed
cnnrr~n;ng the use of muramyl peptide ~ , ~c for
diseases of the skin, and none of these have involved
psoriasis or other ; nfl; tory conditions. Most skin
applications have involved the potential anti-cancer
benefits of this class of compound. For example,
Talmadge, JE et al ~Cancer Res 46:1160-3 (1986)) found
2 1 946 7
~,
that tke muramyl pepeide analcsue ~TP-?E ~as a~le to
retard -he grcw~:l of pri~ary skin cancers. In anos..er
study (Gree nals;. D and Gamelli, RL, Jourual of ~rauma
27:5;0-L !lga7)), the use of .~DP was ~YA~in~ n wound
healing. Howel~er, in this case neither br~triA7 nor
deleterious ef-ects ~ere seen. Elsewhere, the local
injection of ~DP with an antigen has been shown to
enhance the subsequent cutaneous ~delayed type
hypersensitivit~'' response to that antigen (Tsu~imoto, M
et al, Mic-obiol l~unol. 23:933-936 (1979)).
US-A-4357322 tiCrlos~ the use of various muramyl and
desmethylmuramyl dipeptides in treating ;nfl tt~n. ~0
. mention, however. is made o_ GMDP or psoriasis.
Azneimittel Forschung Drug Research, 38, 7A: 1002-lO09
(1988) provides a review of the phArmArologica
properties of Muroctasin.
EP-A-0406175 discloses a compound, 3-0-[N-acetyl-muramyl
-L-threonyl-D-isoglutaminyl~-1,2-di-0-palmitoyl-sn-
glycerol, which is disclosed as having immune-~nhAnr~ng
actlvity.
DE-A-3129759 discloses the use o~ certain muramyl peptide
compounds as anti-inflammatory agents.
~O-A-93/10148 discloses the use o~ muramyl peptide
cu~yuunds in the treatment of septic shock.
- In a fi5sr aspec of the present invention there is
provided the use of a muramyl peptlde ~ ~ ' in the
prepara~ion of an agen~ for the treatment or prophylaxis
of an ; nf~ ~ory dermatoiogica~ condition.
~MENDEDSHEET
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _, _ _ _ _
21 94678
4a
Many muramyl pep~ide compounds useful in this invention
fall within general formula I:
R lo CH~
F-' ~OR~
\ NHCOR~
P~CHCOR
wherein:
R' represents a hydrogen atom or a C,-C~ acyl group;
~MEhDED SHEET
WO96/01645 2 ~ 9 4 6 7 8 PCT/GB9S/01619
.
R2 represents a hydrogen atom or a Cl-C2l acyl group;
R3 represents a hydrogen atom or a Cl-C6 alkyl group;
R4 represents a Cl-C2l alkyl group or a Cs or C,~ aryl
group;
Rs represents a hydrogen atom; and
R represents the residue of an amino acid or a
linear peptide built up of from 2 to 6 amino acid
residues, at least one of the residues being optionally
substituted with a lipophilic group;
other than prototype muramyl dipeptide and
desmethylmuramyl dipeptide.
Preferred acyl groups for Rl and R2 are Cl-Cs acyl groups
such as acetyl; it will be appreciated that the carbon
count in the acyl group does not include the carbonyl
moiety. Preferred alkyl groups for R3 are Cl-C~ alkyl
groups such as methyl and ethyl. Preferred alkyl groups
for R~ and Cl-C6 alkyl groups, particularly Cl-Cc alkyl
groups, such as methyl or ethyl; phenyl is a preferred
aryl group.
R preferably represents a mono-, di- or tri-peptide. The
proximal peptide residue ~or the only peptide residue, if
there is only one) is preferably that of an L-amino acid.
Examples include:
L-alanyl L-tryptophanyl
L-valyl L-lysyl
L-leucyl L-ornithyl
L-isoleucyl L-arginyl
L-~-aminobutyryl L-histidyl
L-seryl L-glutamyl
L-threonyl L-glutaminyl
WO96/016~5 2 1 ~ 4 6 78 PCT/GB9~/01619
L-methionyl L-aspartyl
L-cysteinyl L-asparaginyl
L-phenylalanyl L-prolyl
L-tyrosyl L-hydroxyprolyl
L-alanyl is preferred, as is D-threonyl.
The next amino acid from the proximal end of the peptide
is preferably of the D-configuration~ It is preferably
acidic a~a may be D-glutamic or D-aspartic acid or a
mono-, di- or mixed C1-C22 (preferably C,-Cs) alkyl ester,
amide or -C1-C~ alkyl amide thereof. ~The expression
~'mixed" is illustrated when one carboxyl group is
amidated and the other esterified. D-isoglutamine and D-
gl~1t~m~te ~are preferred.
A third amino acid -esidue from the proximal end of the
chain, if there is one. is preferably of the L-
configuration, as indicated above in relation to the
proximal amino acid residue. L-alanyl and L-lysyl are
preferred_
The amino acid residue or linear peptide is optionally
substituted with at least one li porh; l; c group. The
lipophilic group may be a C10-C22 acyl group such as
stearoyl or a di-(C1o-Cz2 acyl)-sn-glycero-3~-hydroxy-
phn5phPryloxy-group wherein for example each of the C10-C22
acyl groups can be a palmitoyl group. The l; rorh; l; c
group may alternatively (or in addition, as more than one
substitution may be present) be a C1-C10 ester group, such
as a C,-C6ièster group: a butyl ester is an example.
Examples of muramyl dipeptides within the scope of
general formula I include:
WO9610164S 2 1 9 4 6 7 ~ P~ 3i l6~9
muroctasin, otherwise known as MDP-Lys (L18) IN2-(N-
acetylmuramyl-L-alanyl-D-isoglutaminyl)-N6-stearoyl-
L-lysine);
MTP-PE (N-acetyl-muramyl-L-alanyl-D-isogllltA~inyl-L-
alanyl-2-(1',2~-dipalmitoyl-sn-glycero-3'-hydroxy-
phosphoryloxy)ethylamide, monosodium);
murabutide (N-acetylmuramyl-L-alanyl-D-glutamine-~-
N-butyl ester); and
t-MDP (N-acetylmuramyl-L-threonyl-D-isoglutamine).
The preparation of muroctasin is disclosed in EP-A-
0021367 and US-A-4317771. The preparation of MTP-PE i8
disclosed in EP-A-0025495. The preparation of murabutide
i8 described in ~,~frAnrler et al, ~. Med. Chem., 25 87
(1982). The preparation of t-MDP can be prepared by
methods known in the art. Patent publications which give
details of the preparations of muramyl peptide s ,,~ ds
generally include BE-A-0834753, BE-A-0834754, BE-
A-0847103, BE-A-0849214, DE-A-2710455, DE-A-2922533, DE-
A-2747379, DE-A-2912865, FR-A-2355505, FR-A-2358159, FR-
A-2375249, EP-A-0004512, EP-A-0002677, JP-A-54063016, JP-
A-54073729, JP-A-55019236, US-A-4082735 and US-A-4082736.
(The preparation of prototype muramyl dipeptide is
disclosed in DE-A-2450355 and US-A-4235771.) All the
~r~ ' C referred to in this specification are
incorporated herein by reference.
Not all muramyl dipeptides useful in the present
invention fall within general formula I. Many fall
within general formula II, which represents a very much
preferred group of compounds for use in the invention:
WO 96/01645 2 1 9 4 6 7 8 ~ c cl6l9
~OCH~ --
~ ~ ~ OH
1~ \NHAc
~ ~¦ H3CCHCOR
H ~
~HAc n
wherein:
R represents a residue of an amino acid or a linear
peptide built of from 2 to 6 amino acid residues, at
least one of the residueg being opt;nn~lly
substituted with a l;rnrhil;c group; and
n is l or 2.
Preferred values for R are as described above in relation
to general formula I. It is particularly yLefeLL~d that
the peptide R correspond to the peptide in prototype MDP
~L-Ala-D-isoGln). Alternatively, in another yLefe
'_'; , R may Leylese.-L h-Ala-D-Glu.
The preferred value for n is 1.
~c __ '~ of general formula II are ~; ~rl o~r~ in US-A-
4395399 and the preferences set out in that c'~ are
equally preferred in the present invention.
Additionally, in this invention, the group R may be
substituted l irorh; l; cally as described above.
One of the most preferred I _ ~ for use in the
W096/01645 2 1 9~678 F~~ .'Cl619
present invention falls within general formula II and i8
N-acetyl-D-gl ucor--; nyl - (~1-4)-N-acetylmuramyl-L-alanyl-
D-;co~ cm;n~ (GMDP), the structure of which is:
HG Ch-
~ ~
HOCH_ ~ ! \!lHAc
~ sl ,HC0-L-Alo-D-isoGln
11~ 'H_
~J HAc
1 0 Gr~mP
This ~ ol1n~ II in US-A-4395399), also known
as glycopin, has already nn~rcJnn~ pre~l ;n;r~l toxicity
testing and phcrr-nok;n~;c investigations required for
licensing for ~l;n;r~l use in the USSR (as it then was).
The acute toxicity in mice, measured by the LDso test is
7 g/kg. This figure shows the I ~_ ' to be almost an
order of magnitude less toxic than muroctasin which has
an LDso value in mice of 625 mg/kg.
While the pyrogenicity of GMDP is sllff;~;~ntly low to
make it suitable for use in the present invention, and
not to have prevented its rl ;n;~l eV~ln~tinn for other
purposes, it may in some circumstances be preferable to
use an even less pyrogenic AnllOcJu~ Such an ~nclo~l~ is
available, and is N-acetyl-D-glll~ nyl- (~1-4)-N-
acetylmuramyl-L-alinyl-D-glutamic acid ~GMDP-A), which is
~ ~ ' III in ~S-A-4395399, and whose structure is as
follows:
.
WO96101645 2 ~ 9 4 6 7 8 PCT1GB95101619
HCi CH~
~' ' jri
\ . IHAc
H~ ,HCO- L--Al o--[)--Glu
NHAc
GMDE -A
Other preferred _ '- within the scope of general
formula II include:
N-acetyl-D-gl~ R~minyl-(~l-4)-N acetylmuramyl-L-alanyl-
L-isoglut~m;n~ (GMDP-LL) which has the structure:
HOCH2
,~OOH
HOClH2 o l
HO~ CHCO--L--Alo-L-i~oGln
NHAc
GMDP - LI,
N-acetyl-D-gl 7l~R~m; nyl - (~l-4)-N acetylmuramyl-L-alanyl-
D-gl ut~m; n~ n-~utyl ester (GMDP-OBu) which has the
~LLU~;LULI:::
WO 96101645 2 i 9 4 6 7 8 ~ 619
HO CH~
k~OOH
\W
~ \ CHCO--L--Ala-D--Gln--OElu
HO~ CH3
NHAc
GMDP - OBu
1~
N-acetyl-D-glucosaminyl-(~1-4)-N acetylmuramyl-L-alanyl-
D-isoglutaminyl-L-lysine (GMDP-Lys) which has the
structure:
HOCH~
o~HOAc
HO CH2
~-- I CHCO--L--Alo--D-isoGln-L--Lys
HO~ CH3
NHAc
GMDP - Ly~
2~ D~-[N-acetyl-D-glucosaminyl-(~1-4)-N-acetylmuramyl-L-
alanyl-D-isoglutaminyl]-N'-stearoyl-L-lysine (GMDP-
Lys(St)) which has the structure:
WO 96101645 2 1 9 ~ 6 7 ~ r~ 6l9
12
HO CH2
~OOH
~$~
HOCH O \NHAc
HO~ CHCO-L-Alc-D-isoGln-L-Lys-COC1 7H35 Na+
NHAc
GMDP-Lys ~St~
Other useful compounds include:
N~-[N-Acetyl-D-glucosaminyl-(~1--4)-N-acetyl-muramyl-L-
alanyl-~-D-glutamyl]-N'-stearoyl-L-lysine which has the
structure:
HO CH.,
~OOH
\S~
HOCH2 ( ) ~NHAc
Ho$~ CHCO-L--Ac--C--Gll--L-Ly~--COC~7H35
NHAc
GMDPA-Lys(St)
N-Acetyl-D-glncnc~;nyl-(~1--4)-N-acetylmuramyl-L-alanyl-
D-glutamic acid dibenzyl ester which has the structure:
WO96/0164~i 2 1 9 4 6 7 8 PCT/GB9Y01619
.
HOCll2
~OOH
)~HA
HO~ CHCO--L--Alc--û--Clu--(OB11)2
1~ HAc
GMDPA~OBzl)z
N-Acetyl-D-glurmr~m~nyl-(~1--4)-N-acetylmuramyl-N-methyl-
~-alanyl-D-isoglutamine which has the structure:
H0 CH2
~OOH
HOCH 0 \NHAc
Ho$~ CHC0-MeAI~I-D-isoGln
NHAc
Me-~MDP
N-Acetyl-D-glucosaminyl-(~1--4)-N-acetylmuramyl-(~1--4)-
N-acetyl-D-glucosaminyl-(~1--4)-N-acetylmuramyl-bis-(~-
alanyl-D-isoglutamine) which has the structure:
WO96/01645 2 1 ~ 4 6 7 8 PCT/GB9S/01619
.
HO CH2
~OOH
~NHAc
~~¦ CHCO--L--Alo-D--isoCln
~ CH3
HOCH2 ~ NHAc
HOCH ~ \
r~ I CHCO--L-Ac-D-isoGln
HO~ CH3
N HAc
(GMDP) 2
N-Acetyl-D-gls~.q~mi nyl- (~1- -4)-X-acetylmuramyl-(~ 4)-
N-acetyl-D-glucosaminyl-(~1--4)-N-acetylmuramyl-bis-(L-
alanyl-D-glutamic acid) which has the structure:
HO CH2
,~OOH
~5~
HOCH2 ( ) ~NHAc
,~o\l CHCO-L-~Ja-D-Glu
=~ ~ ~ CH3
O NHAc
HO~ ~
1~
HOCH ~ \NHAc
~0 ¦ CHCO--L--Alo--D--Glu
HO~ CH3
NHAc
(GMDPA),
WO961016~5 2 1 9 4 6 7 8 . ~I~Dg il~l6l9
N-Acetyl-D-gl~l~ns~m;~yl-(~1--4)-N-acetylmuramyl-(~1--4)-
N-acetyl-D-glucosaminyl-(~~1--4)-N-acetylmuramyl-bis-(L-
alanyl-D-isoglutaminyl-L-lysine) which has the structure:
HO CH2
~OH
HO~ \CHCO L Alo-D-lsoGln-L-Lys
HOCH2 ~ NHAc
HOC~ O \NHAc
HO~ CHCO-L-Alo--D-isoGln-L-LYs
NHAc
(GMDP Lys) 2
N-acetyl-D-glucosaminyl-(~1--4)-N-acetylmuramyl-(p~1--4)-
N-acetyl-D-gln~s~mlnyl-(~1--4)-N-acetylmuramyl-bis-[L
alanyl-D-isoglutaminyl-N~-stearoyl-L-lysine~:
HO CH2
/~ CHCO-----Alo--D--isoGln L LycCOC17 j5
HOCH
3 0 Ho CH2
Ho~ CLICO-L-AIo--D--~soGln--L--4sCOC17H~5 Nc
NLAc
[GMDP-Lys(St)] 2
WO96101645 2~ 9~678 ~ 5cl6l9
N-Acetyl-D-glucosaminyl-(~1--4)-N-acetylmuramyl-L
alanyl-D-isoglutamine l-adamantyl ester which has the
structure-
HO CH2
~OOH
HO CH O \NHAc
Ho$~ CHCO--L--Alo--D-isoGln--OAd
N HAc
GMDP-Ad
L-Threonyl-N'-[N-Acetyl-D-glllrrs~m1nyl-(~ 4)-N-acetyl-
muramyl-L-alanyl-~-D-isoglutaminyl]-L-lysyl-L-prolyl-L-
arginine ~hich has the structure:
HO CH,7
,~OOH
\~O~
2'i I \ ~
HOCH ~ ) \NHAc
H~ CHCO-L--Alo--D-isoGln-Lys(rnr)--Pro-Arg
NHAc
GMDP-tuftsin E
N-Acetyl-D-glucosaminyl-(~1--4)-N-acetyl-muramyl-L-
alanyl-~-D-isoglutaminyl-L-threonyl-L-lysyl-~-prolyl-L-
WO96101645 21 94678 r~ J~ 1619
.
17
arginine which has the structure:
HO CH2
5 ~O~ H
HO CH O \NHAC
~ ~I CHCO-L-Ala-D--isoGln-Thr-Lys-Pro-Arq
HO~ CH3
NHAc
GMDP-tuftsin A
N-Acetyl-D-gl u~r C,~m; nyl- ~1- -4~-N-acetylmuramyl-L-alanyl-
~-D-glutamyl-L-lysyl-L-threonyl-N'-stearoyl-L-lysyl-L-
prolyl-L-arginine which has the structure:
H0 CH2
~OOH
1'~
HOCH o \NHAC
H0~ cHco-L-Ala-D-Glu-Thr-Lys(cocl7H3s)-pro-Arr
NHAC
GMDPA-tuftsin lipophilic
N'-[N-Acetyl-D-glllrr~a~minyl-(~1--4)-N-acetyl-muramyl-L-
alanyl-v-D-isoglutaminyl]-L-lysyl-L-histidyl-L-glycine
amide which has the structure:
WO 96101645 2 1 9 ~ 6 7 8 P~ JI S3 ~I619
18
HO CH2
~OOH
\ NHAc
HOCH2 ( )
./~~ CHCO-L-AlrJ-D-isoGln-Lys-His-Gly-NH2
Ht~ CH3
N HAc
GMDPA-bursin
N-Acetyl-D-gll-nns~m;nyl-(~1--4)-N-acetylmuramyl-L-alanyl-
D-isoglutaminyl-L-glutamyl-L-try~tophan which has the
structure:
HO CH2
~OOH
HOCH o ~NHAc
~ ~¦ CHC0-L-AkJ-D-isoGIn-GIu-Trp
HO~ CH3
NHAc
GMDP-thymogen I
N-Acetyl-D-gl--rn.sr~minyl-(~1--4)-N-acetylmuramyl-L-alanyl-
D-isoglutaminyl-~-aminohexanoyl-L-glutamyl-L-tryptophan
which has the structure:
WO96/016~5 219 4 67~ r .~ 1619
19
H0 CH
,k~OOH
0 C 2
~ ~¦ CHC0-L-Alo-D--isoGln-Ahx--Glu--Trp
H0~ CH~
NHAc
GMDP-thymogen II
N~-[N-Acetyl-D-glucosaminyl-(~1--4)-N-acetyl-muramyl-L-
alanyl-D-isoglutaminyl]-N'-stearoyl-L-lysyl-L-glutamyl-L-
tryptophan which has the structure:
HO CH2
~OOH
HO CH ~ \NHAC
HO~ CHCO--L--Alo--D--icoGln--Lyc(COC1 ~H35)--Glu--rSp
N HAc
2 5 GMDP-thymogen III
N-acetylmuramyl-L-threonyl-D-isoglutamine which has the
structure:
WO96101645 2 I q~78 r~ 1619
HOCH2
~O OH
OH~NHAc
CHCO- L--~hr-D -isoGln
CH3
Thr-MDP
N-acetylmuramyl-L-alanyl-D-glutamine n-butyl ester which
has the structure:
HO CH2
,~OOH
~5~
bH~NHAc
CHCO-L--Ala-D-Gln--OC, Hg
CH3
Murabutide
In the above structures, the following abbreviations are
used:
Bzl - benzyl;
Me - methyl;
Ahx - ~-Am;n~An~yl
The most preferred compound ~s GMJP followed by GMDP-A,
and murrbutide.
W096/01645 2 1 9 4 6 7 8 PCT1GB95/01619
21
,ilu-m,-~minyl-muramyl dipeptides within the scope of
general formula II can be prepared relatively cheaply and
in reasonably large quantities by the process disclosed
in ~S-A-4395399. The preparation disclosed is based on
the extraction and purification of the ~;c~c-hcride
-o~nPnt from the bacterium Micrococcu- 7ysodecticus and
its subsequent chemical linkage to a dipeptide
8ynthGc; CQ~ for example by conventional peptide
chemistry. ~owever, the disaccharide may equally well be
chemically synthesised using standard sugar chemistry.
Tnfl. tory dermatological conditions treatable, or
preventable, by means of the invention include all types
of psoriasis, including discoid or plaque psoriasis,
flexural psoriasis, scalp psoriasis, palmar/plantar
psoriasis, guttate psoriasis, erythrodermic psoriasis and
pustular psoriasis, psoriatic arthritis and changes in
the nails resulting from psoriasis.
The effect of GMDP in psoriasis has been studied in
clinical trials, which are described in more detail in
Example l below. The PASI (psoriasis area and severity
index) of treated individuals tended to fall during
treatment, and a number of individuals even showed
complete clearing of lesions. Articular symptoms of
psoriatic arthritis were also improved by GMDP.
Individuals receiving placebo tablets showed minimal
~ LOV. ', some worsening or no change.
As with many treatments for psoriasis, the exact
~ -h~ni~m by which compounds use~ul in the invention
WO96101645 2 t 9 4 6 7 8 PCT1GB95101619
causes iL~ Lt is not known. In fact, lt is
extremely surprising that muramyl peptide compounds
should have this b~n~ effect as muramyl peptides
are generally considered to be pro-inflammatory
; nstimulants, whereas regression of ;n~ d lesions
would generally be considered as re~uiring anti-
inflammatory treatment. It has even been described in
the literature that treatment with interferon, another
"immunostimulator" can in fact ~c~rha~e psoriasis
(Funk J; Langeland T; Schrumpf E; Hanssen LE Br
Dermatolo~y 12S: 463-5 (l99l), Pauluzzi P, Kokelj, F,
Perkan, V, Pozzato, ~, Moretti, M. Acta Dermatol
Venereol 73:395 (1993)).
Some experimental studies have been performed which
provide insight into the possible m~rh~n; ~m of action of
muramyl peptide compounds, particularly GMDP, ~n the
skin, and also address the potential scope cf the
invention. However, the effectiveness of the invention
is not a~fected by the relevance of these experiments or
the accuracy of their interpretation.
Thus, as is described in detail in Example 2 below, the
muramyl peptide compound GMDP was applied to the skin of
mice in solution in ethanol. At control sites, ethanol
alone was applied. Some groups of animals received
irradiatlon with ultra violet light (UVB) or received an
application of cis urocanic acid (cUCA), both treatments
known to provoke changes in the cutaneous immune system.
Like UVL3 and cUCA, GMDP treatment caused a loss of ATPase
staining and retraction of dendritic processes of the
epidermal dendritic cells, which is generally associated
with a loss of immunological function. i.e., the GMDP
WO96101645 2 ~ 9 4 6 ?~ r~ ,5,~1619
.
23
reduced the potential i ~activity of the skin. In
this respect, it is observed that W 3 phototherapy alone
is a treatment for psoriasis, thereby supporting the
efficacy of muramyl peptide compounds in the invention.
In other experiments, it was determined that unlike ~3,
GMDP does not cause migration of dendritic cells from the
epidermis to draining lymph nodes.
From these experiments it can be ~n~ P~ that GMDP i8
having a fnn~ t~l effect on dendritic Langerhans
cells, which are the primary immune component of the
epidermis. Since there is evidence to support a role for S
Langerhans cells in the pathogenesis of psoriasis (Placek
et al, Acta Derm Venereol (Stockh) 68:369-77 (1988)), it
is possible that a down-regulation of the activity of
these cells is able to reduce the severity of the
disease. The experiments with the mice were performed by
topical application of GMDP, but GMDP is kno~n to be
orally bioavailable, and so GMDP orally administered, as
in the clinical trial, could be expected to exert an
effect in the skin.
3ecause of the demonstrated effect on the ~ut~nPovq
immune system on the one hand and an immune system-
related human skin disease (psoriasis) on the other, it
can be expected that muramyl peptides will have utility
in the treatment of a range of immunologically based
;nfl. tory skin diseases for which it has never
previously been proposed. Moreover, as the mucous
membranes lining the buccal cavity, the vagina and the
uterine cervix also contain T,~ngPrh~nq cells, these too
are target organs for muramyl peptide treatment.
WO96/01645 2 t 9 4 6 7 8 PCT/GB95/01619
24
In the second aspect of the present invention there is
provided the use of muramyl peptide compound in the
preparation of an agent for the treatment or prophylaxis
of immun-e:-related diseases of the skin and mucous
S membranes. These include, but are not restricted to,
endogenous eczema (otherwise known as atopic eczema or
atopic ~ermatitis), seborrhoeic eczema, pompholyx,
contact dermatitis, urticaria, erythroderma, lichen
planus, vitiligo and alopoecia areata.
The efficacy of muramyl peptide ~ , ~c in the
invention has been demonstrated using oral
administ~a~ion. The formnl~;nn in this instance
consisted of tablets ~nnt~in;ng pharmaceutically
acceptable excipients, namely lactose, starch,
polyvidone, magnesium stearate and talc. Muramyl peptide
compounds may be formulated for sustained and/or delayed
delivery if desired. Gastric coating is another option.
The precise oral dosage for administration will always be
tha~ deemed suitable by the clinician or physician.
Subject to that, a daily oral dosage in the range of from
O.l to ~D0 mg per day (or per unit dose) may be found
acceptable, with a range of 0.5 to 50 mg being preferred.
Within this preferred range, an optimal daily doeage
would be within the range 2 to 3Q mg or indeed 2 to 20
mg.
In addition, the duration of ~m;n;qtnation may be
varied. The duration will of course depend, to some
extent, on dosage level, i.e. lower dose results in
longer required duration of dosage-. In general terms,
the duration of dosage will be in the range of 1-60 days,
prefera'oly 1-30 days and most preferably 1-14 days.
W096101645 2 1 9 4 6 7 8 A ~ 1~ ~, ~1619
.
It has been demonstrated that muramyl peptide compounds
do have an affect on the cutaneous immune system after
topical administration. Thus, despite the advantages
inherent in an oral dosage form, it may be ~tPrminod
that for certain specific instances a topical formulation
of muramyl peptide compound(s) will be preferred, when
for example functioning of thé gastrointestinal tract of
a patient is compromised by disease or surgery, or in the
case of particularly recalcitrant skin diseases where a
particularly high local concentration of muramyl peptide
compound is desired.
According to a third aspect of the invention, there is
provided a topical formulation of a muramyl peptide
compound.
The formulation, which may be presented as an o; n ~,
lotion or cream, may contain phar~cont~A7ly acceptable
excipients or carriers, with due regard being taken of
the ability of the formulation effectively to release the
muramyl peptide ir.to the skin. The formulation may even
enhance the passage of said muramyl uu,..~uu~ds by the
incorporation of so called pe~ ti~n onhAn~or~,
Muramyl peptide compounds may be used either singly or in
combination with each other in the invention. Also,
muramyl peptide compounds may be used in combination with
other ~omro-ln~c~ whether formulated together or
separately; for example, a muramyl peptide c ~ ' may
be administered orally and another _ ~ administered
topically. When ~-sed in combination, either with each
other or with other compounds, administration can be
simultaneous, separate or se~uential.
In a final aspect, the present invention provides a
method for the prophylaxis or treatment of an
Wo96tO1645 2 ~ 9 ~ ~ 7 g PCT/GB9~01619
26
in~1 tory dermatological condition, comprising
administering to a patient a muramyl peptide compound.
Preferred features of each aspec~ of the invention are as
for each other aspect, mutatis mutandis.
The invention will now be illustrated by the following
non-limiting examples and drawings, in which:
FIGURE l: is a plot showing changes in psoriasis
severity and area index (PASI) during the course of
treatment with GMDP or placebo.
EXA~P~E 1
The use of GMDP i~ the treatment of psoriasis.
A Open label trial
A preliminary trial in the use of GMDP for psoriasis was
conducted in 8 patients who received GMDP in doses of lO
or 20 mg for a period of 9 to 18 days. In general,
effective reduction of the cutaneous symptoms of
psoriasis was observed. One of the patients had the
variant of psoriasis known as psoriatic arthritis, and
this patient observed a reduction in ~oint paln and
morning s~iffness of joints.
s Placebo controlled trial
MET~ODS
~ineteen individuals with psoriasis (pla~ue psoriasis,
pustular psoriasis or erythrodermic psoriasis) were
r~n~ qP~ either to oral treatment with GMDP tablets (at
WO96101645 2 1 ~ ~ 6 7 ~ PCT/GB95/0l6l9
a dose of 20 mg per day for 10 days, followed by 20 mg
every other day for a further ten days, (i.e. treatment
on days 1,2,3,4,5,6,7,8,9,10,12,14,16, 8 and 20) or an
identical placebo tablet. The trial was "double blind",
in that neither the patient nor the investigator knew
which preparation (GMDP or placebo) was given to
particular patients. Common practice in modern clinical
trials, this double hl ;n~;ng is particularly important in
psoriasis trials where a strong psychological element can
cause i , UV~ t in patients who "know" they are
receiving a potential treatment.
The severity and area of the psoriasis in all of the
patients was measured at entry to the trial and at
intervals out to about 20 days according to the
internationally recognised PASI (psoriasis area and
severity index) system (Frederiksson and Pettersson,
Dermatologica 157:238-244 (1978)). Changes in individual
patients are shown in Fig 1. In this graph, the starting
condition of patients was standardised at "100~", and
then at subse~uent ~min~tinnq the PASI score is shown
as a percent of starting score. It is clear that the
PASI of treated individuals tended to fall during
treatment, and a number of individuals even showed
complete clearing of lesions. Individuals receiving
placebo tablets showed minimal i _ uv~ ~, some
worsening or no change. At the time of last , in~t;on~
the mean score for treated patients was 6.0 and the mean
score for control patients was almost twice that, 11.7.
W096/016~5 2 1 ~ 4 ~ 7 8 PCT1GB95/01619
Z8
~PLE 2
The use of OEMDP in the treatment of psoriasis - n~d
with the Eequential use of other p30riasis treatments.
~ ~
In a double blind, placebo-controlled clinical trial of
GMDP, 14.=patients received active ~GMDP) treatment (30
mg/day for lO days). Of these, all except one subject
showed i1~1~L~V~ 1L as measured by a decrease in their
PASI score.
Following~ initial ill~L~V~ t during the lO days'
treatment with GMDP, several of the patients elected to
receive I~rther psoriasis therapy other than GMDP. This
included W irradiation, topical salicylic acid, oral
magnesium sulphate and vitamin A derivatives.
I111~L~V. o~ntin11o~ in these patients, clearly
demonstrating that GMDP tro~t~ t can be safely and
eifectively followed by other treatments, i~ that is
considered appropriate by the administering physician.
~MPLE 3
The eifect of GMDP on ~TPase expression by ~pi~or~-
dendritic cells in the mouse.
~Q~
The method used in this experiment has been described in
detail by Norval et al ~Norval, M, Gilmour, J W, and
Simpson T J, Photodermatol Phot~ ~7 Photomed 7:243-8
(1990) )
GMDP was dissolved in ethanol at l mg/ml and O.l mg/ml.
Twenty microlitres o~ this solution, or vehicle (ethanol)
WO96/01645 219467~ P~ 6l9
.
control was painted on to the dorsal sides of the ears of
mice which had previously been "stripped" with adhesive
tape to remove the superficial barrier layers. Other
mice were irradiated with a dose of W3 (144 mJ/cm2) known
to 1 nfl nPn~e Langerhans cell (LC) ATPase expression. In
another experiment of this type, the positive control was
cis-urocanic acid (cUCA), a substance generated in the
epidermis under the influence of UV5, and believed to be
implicated in the mediation of UV3-induced changes in ~C
function.
Twenty four hours later mice were killed, epidermis was
removed from the dorsal surface of the ears, and stained
to reveal ATPase activity. Cells showing staining were
counted and expressed as cells/mm2. The morphology of the
cells was also noted.
RESULTS AND DISCUSSION
Results are summarised in Tables 2 and 3. GMDP at the
two doses studied significantly reduced the number of
AT~ase positive cells as compared to vehicle controls.
The positive control treatments (UV3 irradiation and c-
UCA) also reduced cells, as expected.
TA3~E 2
Treat~ent No of ATPa~e -ve cells/mm2
(meanlSD)
Ethanol 420 (30)
GMDP 1 mg/ml 350 (20)
GMDP 0.1 mg/ml 325 (20)
UV3 160 (25)
WO96/016~5 2 ~ ~ 4 6 7 ~ . s 16l9
TABLE 3
Treatment No oL ATP~se +ve cells/~m2
(mean+SD)
Ethanol 445 (30)
GMDP 1 mg/ml 35D (30)
GMDP 0.I mg/ml 280 (20)
c-UCA 325 (30)
MPT.Ti! 4
The effect oL GMDP on the migration oL ~ri~r~ 7
dendritic cell~ to draining lymph node~.
In this example, the ability of GMDP to provoke migration
of dendritic epidermal cells wa8 ~ inr~r1,
Mice were treated with ethanol, GMDP at 1 mg/ml in
ethanol, or U~3 at g6 mJ/cm2. Forty eight hours later
mice were killed, the auricular (ndraining~) lymph nodes
excised, and dendritic cells purified and counted.
RESULTS ~Nn DIS W SSION
Results are summarised in Table 4.
Treatment No Of dendritic cells
per lyrph node (~ean_SD)
Ethanol 1750 ~400)
GMDP 1 mg/ml 2200 (250)
U~3 8000 (1800)
u~n3 signlficantly r~nh~nr r~r1 the number of dendritic cells
in lymph nodes. GMDP showed no significant effect.
