Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHODS FOR TREATING HOT FLASHES AND GYNAECOMASTIA
Background of the Invention
Menopausal women frequently experience a variety of symptoms which have
been attributed to estrogen deprivation due to ovarian failure. Occurring in
up to 85% of
menopausal women, the most common and most characteristic symptom of menopause
is an episodic disturbance consisting of sudden flashing and perspiration,
referred to as
the "hot flash." Vasomotor hot flashes are also the most frequent side effect
associated
with the anti estrogen drug Tamoxifen, used in the treatment of breast cancer.
Non-
hormonal related causes of hot flashes also exist even though they are not
very common.
One example is a deficiency or low level of alcohol dehydrogenase. People with
such
deficiency may be particularly prone to flushing with alcohol intake. Other
rare causes
of hot flashes include carcinoid syndrome or pheochromocytoma.
Although hot flashes are most commonly treated by estrogen replacement
therapy (orally, transdermally, or via an implant), some women cannot tolerate
estrogen
treatment. In addition, estrogen is usually not recommended for women with
hormonally sensitive cancers (e.g. breast cancer). Other options have been
studied for
the treatment of hot flashes, including steroids, alpha-adrenergic agonists,
and beta-
blockers, with varying degree of success. Progestins, like Megestrol acetate
and
Medroxyprogesterone, have been shown to reduce hot flashes to 25-85 % and 75-
100 %,
respectively, but the long-term effects of progestin therapy have not been
studied. It is
possible that side effects like thromboembolic disorders, edema, weight gain,
lipid
changes, and death due to cardiovascular disease make the use of this
treatment
unattractive.
Central nor adrenergic activity is believed to play a a role in the initiation
of hot
flashes. Therefore, agents that inhibit the release of nor epinephrine have
also been used
to ameliorate hot flashes. CLONIDINETM (administered transdermally) reduced
the
frequency and severity of hot flashes due to Tamoxifen, but the results for
orally
administered clonidine varied. Side effects associated with the clonidine
treatment
included drowsiness, constipation, orthostatic hypotension, dry mouth,
headache,
nausea, fatigue, and decreased libido. Methyldopa was shown to decrease hot
flashes by
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30%, but it was associated with fatigue, weakness, dizziness, and nausea.
Mixed reports
exist for the use of Naproxen beta-blockers, VERALIPRIDETM and NAXOLONETM.
Gynaecomastia is the development of excess breast tissue in the male. There
may be a physiological (puberty, aging) or a pathological (drugs, tumors,
liver and renal
failure, hormonal imbalances) basis to it. Whatever the aetiology, the
ultimate cause of
gynaecomastia is an increase in the estrogen : testosterone ratio. Surgical
correction
(mastectomy) is a common method of treatment, although a rather costly one.
Recently,
liposuction has also been used as a method of treatment. This method, however,
does
not completely cure true gynaecomastia, because it removes fat rather than
breast tissue.
Anti-estrogens have also been tried. Tamoxifen and DANAZOLTM have been shown
to
reduce gynaecomastia in approximately 70% of middle aged men (Parker LN et aI,
Metabolism, 1986, 35: 705-8, Jones DJ et al, Ann Roy Coll Surg, 1990, 72:286-
8).
CLOMIPHENETM proved to be unsuccessful and was associated with adverse side-
effects (Ploudre PV et al, Am. J. Dis. Child., 1983, 137: 1080-2).
Accordingly, treatment methods are needed for patients suffering from hot
flashes or gynaecomastia, which are effective and will not result in adverse
side-effects.
Suramary of the Invention
This invention provides effective treatments for inhibiting hot flashes or
gynaecomastia in subjects suffering from these disorders. In general, the
treatment
methods of the invention involve administering an LHRH antagonist to a subject
suffering from, or at risk for suffering from, hot flashes or gynaecomastia
such that the
hot flashes or gynaecomastia are inhibited in the subject.
Thus, one aspect of the invention features a method of inhibiting hot flashes
in a
subject by administering an LHRH antagonist to the subject such that hot
flashes are
inhibited in the subject. In another embodiment, the invention provides a
method of
treating a subject for hot flashes in which a subject in need of treatment for
hot flashes is
first selected for treatment and then an LHRH antagonist is administered to
the subject
such that the subject is treated for hot flashes. The subject in need of
treatment for hot
flashes can be a subject currently suffering from hot flashes or a subject
that is at risk for
suffering from hot flashes. In an especially preferred embodiment, the
invention
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provides a method of treating a subject for menopause-related hot flashes. In
this
method, a subject in need of treatment for menopause-related hot flashes is
selected and
an LHRH antagonist is administered to the subject such that the subject is
treated for
menopause-related hot flashes. The subj ect in need of treatment for menopause-
related
hot flashes can be a subject currently suffering from menopause-related hot
flashes or a
subject at risk for suffering from menopause-related hot flashes. In addition
to treatment
for menopause-related hot flashes, the methods of the invention can be used to
treat hot
flashes that result from other disorder or treatments, such as hot flashes
that are the result
of prostate cancer treatment, tamoxifen acetate treatment, alcohol
dehydrogenase
deficiency or carcinoid syndrome/pheochromocytoma.
Another aspect of the invention pertains to a method of inhibiting
gynaecomastia
in a subject by administering an LHRH antagonist to the subject such that
gynaecomastia is inhibited in the subject. In another embodiment, the
invention
provides a method of treating a subject for gynaecomastia in which a subject
in need of
treatment for gynaecomastia is first selected for treatment and then an LHRH
antagonist
is administered to the subject such that the subject is treated for
gynaecomastia. The
subject in need of treatment for gynaecomastia can be a subject currently
suffering from
gynaecomastia or a subject that is at risk for suffering from gynaecomastia.
In a
preferred embodiment, gynaecomastia in the subject is the result of a hormonal
balance.
Any LHRH antagonist that effectively inhibits the activity of the LHRH-R
receptor can be used in the methods of the invention. However, in a
particularly
preferred embodiment, the LHRH antagonist has the structure: Ac-D-Nal~, 4-Cl-D-
Phe2,
D-Pal3, N-Me-Tyrs, D-Asn6, Lys(iPr)g, D-Alal~-LHRH (referred to herein as PPI-
149).
In another preferred embodiment of the invention, the subject is a mammal,
e.g.,
most preferably a human.
In yet another preferred embodiment, the LHRH antagonist is administered to
the
subject by a parenteral route, preferably by injection, most preferably by
intramuscular
or subcutaneous/ intradermal injection.
In still another preferred embodiment, the LHRH antagonist is administered to
the subject in a pharmaceutically acceptable formulation. The pharmaceutically
acceptable formulation can be a dispersion system. For example, the
formulation can be
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lipid-based (e.g., a liposome formulation) or polymer-based (e.g., a polymeric
microsphere). In a particularly preferred embodiment, the formulation
comprises the
LHRH antagonist in an insoluble complex with an anionic carrier macromolecule
(e.g.,
carboxymethylcellulose).
In preferred embodiments, the LHRH antagonist is administered at, for example,
a dosage of about 15-300 pg/kg/day, 15-200 pg/kg/day or I S-100 pg/kg/day. The
LHRH antagonist can be administered continuously using a sustained-release
formulation, e.g., a formulation in an osmotic pump or a formulation that
allows for
slow-release of the LHRH antagonist into the tissue of the subject. For
sustained
treatment of a subject, the LHRH antagonist can be administered to the subject
for at
least one month, preferably three and more months and even more preferably six
months. To achieve sustained treatment for extended periods of time, it may be
necessary to readminister a sustained release formulation. For example, a
sustained
release formulation that delivers the LHRH antagonist for a period of one
month can be
1 S readministered on a monthly basis to achieve sustained treatment for
several months
(e.g., 6 months). Similarly, a sustained release formulation that delivers the
LHRH
antagonist for a period of one week can be readministered on a weekly basis to
achieve
sustained treatment for several weeks. The sustained release formulations
provided
herein (see e.g., Example 3) can deliver an LHRH antagonist for a period of at
least
about one month and thus can be readministered on a monthly basis to achieve
extended
treatment.
The LHRH antagonist can be administered to the subject alone or in combination
with at least one other therapeutic agent. Examples of other therapeutic
agents that may
be administered with the LHRH antagonist include LHRH agonists, antiandrogens,
antiestrogens and inhibitors of sex steroid biosynthesis.
In another embodiment, the LHRH antagonist is administered in combination
with a sex hormone, such as estrogen or testosterone. For example, estrogen
replacement therapy is often used during (and after) menopause to reduce
certain
symptoms associated with menopause and thus one in embodiment of the
invention, a
subject is treated with both estrogen (and/or other related female sex
hormone(s), such as
progesterone) and an LHRH antagonist. The use of an LHRH antagonist in
combination
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with the estrogen (and/or other related female sex hormone(s)) may allow for
the use of
lower dosages of the hormone than when the hormone is used alone. Similar
combination therapy can be used in disorders where testosterone (and/or other
related
male sex hormone(s)) is administered.
Other features and advantages of the invention will be apparent from the
following detailed description, and from the claims.
Detailed Description of the Invention
The present invention provides a method of inhibiting hot flashes or
gynaecomastia in a subject. The methods of the invention generally feature
administering an LHRH antagonist to a subject such that hot flashes or
gynaecomastia
are inhibited in the subject. In certain embodiments, the methods of the
invention
involve selecting a subject in need of treatment for hot flashes or
gynaecomastia and
administering an LHRH antagonist to the subject such that the subject is
treated for hot
flashes or gynaecomastia. The methods of the invention for treating hot
flashes can be
used to treat hot flashes that result from, for example, menopause, tamoxifen
acetate
treatment, prostate cancer treatment, alcohol dehydrogenase deficiency, or
carcinoid
syndrome/pheochromocytoma. The methods of the invention for treating
gynaecomastia
can be used to treat gynaecomastia that results from, for example, a hormone
imbalance.
Although the exact pathophysiology of the hot flash is unknown, it appears to
be
related to an alteration in the set point of the thermoregulatory center
located in the
hypothalamus. Blood sampling in women experiencing hot flashes, has documented
that
the onset of a hot flash is correlated with the release of gonadotropin
releasing hormone
(GnRH} in the hypothalamus, and a subsequent luteinizing hormone (LH) pulse.
This
rise in the levels of LH is thought to cause a decrease in the set point of
the
thermoregulatory center. In an attempt to restore equilibrium, a hot flash is
produced.
Although not intending to be limited by mechanism, the ability of the LHRH
antagonists
of the invention to inhibit hot flashes is thought to result, at least in
part, from its
inhibition of the LH pulse that decreases the set point of the
thermoregulatory center.
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As used herein, the term "LHRH antagonist", refers to a compound that inhibits
the luteinizing hormone releasing hormone receptor, such that release of
luteinizing
hormone is inhibited. The term "LHRH antagonist" rnay be used interchangeably
with
the term "LHRH-R antagonist" to refer to compounds that inhibit LHRH-R such
that
release of LH is inhibited. LHRH antagonists have been described in the art;
see e.g.,
U.S. Patent 5,470,947 to Folkers et al.; Folkers et al., U.S. Patent 5,843,901
to Roeske et
al.; U.S. Patent 5,413,990 to Haviv; U.S. Patent 5,300,492 to Haviv; U.S
Patent
5,371,070 to Koerber et al.; U.S. Patent 5,296,468 to Hoeger et al.; U.S.
Patent
5,171,835 to Janaky et al.; U.S. Patent 5,003,011 to Coy et al.; U.S. Patent
4,431,635 to
Coy; U.S. Patent 4,992,421 to De et al.; U.S. Patent 4,851,385 to Roeske; U.S.
Patent
4,801,577 to Nestor, Jr. et al.; and U.S. Patent 4,689,396 to Roeske et al.
For example, preferred LHRH-R antagonists which can be used in the methods
of the invention include peptides comprising a structure:
A-B-C-D-E-F-G-H-I-J
wherein
A is pyro-Glu, Ac-D-Nal , Ac-D-Qal, Ac-Sar, or Ac-D-Pal
B is His or 4-Cl-D-Phe
C is Trp, D-Pal, D-Nal, L-Nal-D-Pal(N-O), or D-Trp
D is Ser
E is N-Me-Ala, Tyr, N-Me-Tyr, Ser, Lys(iPr), 4-Cl-Phe, His, Asn, Met, Ala, Arg
or Ile;
F is
X Y
\N
R
wherein
R and X are, independently, H or alkyl; and
Y comprises a dipolar moiety;
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_ 'j
G is Leu or Trp;
H is Lys(iPr), Gln, Met, or Arg
I is Pro; and
J is Gly-NH2 or D-Ala-NH2;
or a pharmaceutically acceptable salt thereof. In preferred embodiments, Y is
selected
from the group consisting of ylids, tertiary amine oxides, nitrite oxides,
pyridine-N
oxides, and pyridinium zwitterions. In particularly preferred embodiments, Y
is an ylid,
a pyridine-N-oxide or a pyridinium zwitterion. In a preferred embodiment, the
peptide
comprises a structure:
Ac-D-Nal-4-Cl-Phe-D-Pal-Ser-Tyr-D-Pal(N-O)-Leu-Lys(iPr)-Pro-D-Ala-NH2.
In another preferred embodiment, the peptide comprises a structure:
Ac-D-Nal-4-Cl-D-Phe-D-Pal-Ser-Tyr-D-Pal(CH2C00-)-Leu-Lys(iPr)-Pro-Ala-
NH2;
or a pharmaceutically acceptable salt thereof.
1 S In another aspect, an LHRH-R antagonist used in the methods of the
invention
includes a peptide comprising a structure:
A-B-C-D-E-F-G-H-I-J
wherein
A is pyro-Glu, Ac-D-Nal , Ac-D-Qal, Ac-Sar, or Ac-D-Pal
B is His or 4-Cl-D-Phe
C is Trp, D-Pal, D-Nal, L-Nal-D-Pal(N-O), or D-Trp
D is Ser
E is N-Me-Ala, Tyr, N-Me-Tyr, Ser, Lys(iPr), 4-Cl-Phe, His, Asn, Met, Ala, Arg
or Ile;
F is D-Arg, D-Lys(iPr), D-Pal(iPr), D-Cit or Q, wherein Q has a structure
X Z
~N
R O
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_g_
wherein
R and X are, independently, H or alkyl; and
Z comprises a cationic moiety selected from the group consisting
of cationic pyridinium moieties and sulfonium moieties, with the proviso that
the
cationic moiety is not N-methyl pyridinium;
G is Leu or Trp;
H is Lys(iPr), Gln, Met, Arg or Q;
I is Pro; and
J is Gly-NH2 or D-Ala-NH2;
with the proviso that at least one of F and H is Q;
or a pharmaceutically acceptable salt thereof.
In preferred embodiments, F is Q and Z is a cationic pyridinium moiety. In
preferred embodiments, Z is an N-benzyl pyridinium moiety. In other preferred
embodiments, F is Q and Z is a sulfonium moiety. In yet other preferred
embodiments,
I S H is Q and Z is a sulfonium moiety. In a particularly preferred
embodiment, the peptide
comprises a structure
Ac-Sar-4-Cl-D-Phe-D-Nal-Ser-Tyr-D-Pal(Bzl)-Leu-Lys(iPr)-Pro-Ala-NH2;
or a pharmaceutically acceptable salt thereof. In another particularly
preferred
embodiment, the peptide comprises a structure:
Ac-D-Nal-4-Cl-D-Phe-D-Trp-Ser-Tyr-D-Met(S+Me)-Leu-Arg-Pro-Ala-NH2;
or a pharmaceutically acceptable salt thereof. In a particularly preferred
embodiment,
the peptide comprises a structure:
Ac-D-Nal-4-Cl-D-Phe-D-Pal-Ser-Tyr-D-Arg-Leu-Met(S+Me)-Pro-Ala-NH2;
or a pharmaceutically acceptable salt thereof.
In another aspect, an LHRH-R antagonist used in the methods of the invention
includes a peptide comprising a structure:
A-B-C-D-E-F-G-H-I-J
wherein
A is p-Glu, Ac-D-Nal , Ac-D-Qal, Ac-Sar, or Ac-D-Pal
B is His or 4-CI-D-Phe
C is Trp, D-Pal, D-Nal, L-Nal-D-Pal(N-O), or D-Trp
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D is Ser
E is N-Me-Ala, Tyr, N-Me-Tyr, Ser, Lys(iPr), 4-Cl-Phe, His, Asn, Met, Ala, Arg
or Ile;
F is
X T
\N
R i
wherein
R and X are, independently, H or alkyl; and
T comprises a receptor-modifying moiety;
G is Leu or Trp;
H is Lys(iPr), Gln, Met, or Arg
I is Pro; and
J is Gly-NH2 or D-Ala-NH2;
or a pharmaceutically acceptable salt thereof.
In preferred embodiments, T is selected from the group consisting of ylids,
sulfonium moieties, a-halocarbonyls, sulfates, sulfonates, alkyl halides and
benzyl
halides. In a particularly preferred embodiment, T is an a-halocarbonyl.
In another embodiment, an LHRH-R antagonist used in the methods of the
invention includes a peptide comprising a structure:
A-B-C-D-E-F-G-H-I-J
wherein
A is pyro-GIu, Ac-D-Nal , Ac-D-Qal, Ac-Sar, or Ac-D-Pal
B is His or 4-Cl-D-Phe
C is Trp, D-Pal, D-Nal, L-Nal-D-Pal(N-O), or D-Trp
D is Ser
E is N-Me-Ala, Tyr, N-Me-Tyr, Ser, Lys(iPr), 4-Cl-Phe, His, Asn, Met, Ala, Arg
or Ile;
F is
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X M
\N
R
wherein
R and X are, independently, H or alkyl; and
M comprises an N-acyl hydrophilic moiety;
G is Leu or Trp;
H is Lys(iPr), Gln, Met, or Arg
I is Pro; and
J is Gly-NH2 or D-Ala-NH2;
or a pharmaceutically acceptable salt thereof.
In another aspect, an LHRH-R antagonist used in the methods of the invention
includes a peptide comprising a structure:
A-B-C-D-E-F-G-H-I-J
wherein
A is pyro-Glu, Ac-D-Nal , Ac-D-Qal, Ac-Sar, or Ac-D-Pal
B is His or 4-Cl-D-Phe
C is Trp, D-Pal, D-Nal, L-Nal-D-Pal(N-O), or D-Trp
D is Ser
E is N-Me-Ala, Tyr, N-Me-Tyr, Ser, Lys(iPr), 4-Cl-Phe, His, Asn, Met, Ala, Arg
or Ile;
F is
X L
\N
R
wherein
R and X are, independently, H or alkyl; and
L comprises a small polar moiety;
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G is Leu or Trp;
H is Lys(iPr), Gln, Met, or Arg
I is Pro; and
J is Gly-NH2 or D-Ala-NH2;
or a pharmaceutically acceptable salt thereof.
In preferred embodiments, L is selected from the group consisting of D-Cit, D-
Asn, D-Gln, and D-Thr.
Preferred LHRH antagonists are those having good LHRH antagonist activity
and low histamine-releasing activity (e.g., an ED50 for histamine release in a
standard in
vitro histamine release assay of at least 3 pg/ml, more preferably at least S
pg/ml, and
still more preferably at least 10 pg/ml) and that exhibit water solubility.
The efficacy of
candidate LHRH antagonists in inhibiting LH release can be assayed, for
example, in an
animal model such as that described in Corbin and Beanie, Endocrine Res.
Commun. 2:1
(1975). In this assay, the LHRH antagonistic activity of a candidate compound
is
assayed by measuring the antiovulatory activity (AOA) of the compound in rats.
Preferably, histamine-releasing activity is assayed by the method described in
U.S.
Patent 4,851,385 to Roeske. Preferred LHRH antagonists with low histamine-
releasing
activity and water solubility include compounds disclosed in PCT Publication
WO
96/40757, the entire contents of which are expressly incorporated herein by
reference.
An especially preferred LHRH antagonist comprises the structure: Ac-D-Nal~, 4-
Cl-D-
Phe2, D-Pal3, N-Me-TyrS, D-Asn6, Lys(iPr)8, D-Ala»-LHRH (referred to as PPI-
149
and described further in U.S. Patent 5,843,901).
Alternatively, the methods of the invention can be used with any of a variety
of
compounds known in the art to have LHRH antagonist activity. These LHRH
antagonists typically are analogues of the LHRH decapeptide, non-limiting
examples of
which include Antide, Nal-Glu (having the structure: Ac-D-Nal(2)1, 4-Cl-D-
Phe2, D-
Pal3, ArgS, D-Glu6 (AA), D-Ala»-LHRH) and SB-75 (also known as
CETRORELIXTM) (having the structure: Ac-D-Nall, 4-Cl-D-Phe2, D-Pal3, D-Cit6, D-
Ala»-LHRH). Another example of an LHRH antagonist that can be used in the
method
of the invention has the structure: Ac-D-Nall, 4-Cl-D-Phe2, D-Pal3, N-Me-Tyrs,
D-
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Lys(N-epsilon-nicotinoyl)6, Lys(iPr)g, D-Alal ~-LHRH (described further in
European
Patent EP 400 065 B).
As used herein, the term "inhibiting" (as in "inhibiting hot flashes" or
"inhibiting
gynaecomastia") is intended to mean reducing or downregulating hot flashes or
gynaecomastia. The term "inhibiting" is intended to include both partial and
complete
inhibition.
As used herein, the term "treating" refers to exposing a subject to a specific
therapeutic regimen for the purpose of relieving a symptom, or preventing a
particular
condition.
As used herein, the term "subject" is intended to include animals susceptible
to
hot flashes and/or gynaecomastia, preferably mammals, most preferably humans.
In a
preferred embodiment, the subject is a primate. In an even more preferred
embodiment,
the primate is a human. Other examples of subjects include dogs, cats, goats,
and cows.
The term "hot flash" is an art recognized term that refers to an episodic
disturbance in body temperature typically consisting of a sudden elevation in
body
temperature, usually with accompanied perspiration in a subj ect.
As used herein, the term "anti-estrogen", refers to compounds that antagonize
the
release or action of estrogens. Antiestrogens are known in the art (e.g.,
tamoxifen and
derivatives thereof, such as trioxifene, toremifene and droloxifene) and are
commercially
available (e.g., tamoxifen; trade name: NOLVADEXTM, a product of ICI
Pharmaceuticals).
As used herein, the term "anti-androgen" refers to a compound that antagonizes
the release or action of androgens. Anti-androgens are known in the art (see,
e.g., U.S.
Patent 4,386,080), and are commercially available (e.g., ANDORCURTM, a product
of
Schering A.G.) and include steroidal and nonsteroidal anti-androgens. Specific
examples of nonsteroidal antiandrogens include flutamide (4'-nitro-3'-
trifluorormethyI
isobutyranilide; trade name EULEXINTM; Schering-Plough), bicalutamide and
nilutamide.
As used herein, the term "LHRH agonist" refers to a compound that stimulates
the luteinizing hormone releasing hormone receptor such that luteinizing
hormone is
released (e.g., a compound that mimics the activity of LHRH). An LHRH agonist
can
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have greater LH-releasing activity than natural LHRH (referred to as a
"superagonist"):
Many LHRH agonists and superagonists are known in the art. Commercially
available
LHRH agonists include leuprolide (trade name: LUPRONTM; Abbott/TAP), goserelin
(trade name: ZOLADEXTM; Zeneca), buserelin (Hoechst), triptorelin (also known
as
Decapeptyl, D-Trp-6-LHRH and DEBIOPHARMTM; Ipsen/Beaufour), nafarelin (trade
name" SYNARELTM; Syntex), lutrelin (Wyeth), cystorelin (Hoechst), gonadorelin
(Ayerst) and histrelin (Ortho).
The term "inhibitor of sex steroid biosynthesis" is intended to include
inhibitors
of adrenal sex steroid biosynthesis (e.g., aminoglutethimide) and inhibitors
of testicular
sex steroid biosynthesis (e.g., ketoconazole), or combinations thereof.
Pharmaceutically Acceptable Formulations
In the methods of the invention, the LHRH antagonist typically is administered
in a pharmaceutically acceptable formulation. The pharmaceutically acceptable
formulations of the invention typically contain the LHRH antagonist and a
pharmaceutically acceptable carrier and are intended to include any
formulation
compatible with pharmaceutical administrations, including, for example,
synthetic or
natural polymers in the form of macromolecular complexes, nanocapsules,
microspheres, or beads, and lipid-based formulations including oil-in-water
emulsions,
micelles, mixed micelles, synthetic membrane vesicles, and resealed
erythrocytes.
In a particularly preferred embodiment, the pharmaceutical formulation
comprises an LHRH antagonist (preferably having the structure Ac-D-Nalt, 4-Cl-
D-
Phe2, D-Pal3, N-Me-TyrS, D-Asn6, Lys(iPr)8, D-Alal~-LHRH) in a water-insoluble
complex with a carrier macromolecule, preferably an anionic polymer such as
carboxymethylcellulose, as described in U.S. Application Serial No. 08/762,747
and
corresponding PCT Application No. PCT/US97/22881, the contents of both of
which are
expressly incorporated herein by reference. In brief, the complex of the LHRH
antagonist and a carrier macromolecule is formed by combining the LHRH
antagonist
and the carrier macromolecule under conditions such that a substantially water-
insoluble
complex is formed, e.g., aqueous solutions of the LHRH antagonist and Garner
macromolecule are mixed until the complex precipitates. The complex may be in
the
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form of a solid (e.g., a paste, granules, a powder or a lyophilizate) or the
powdered form
of the complex can be pulverized finely enough to form stable liquid
suspensions or
semi-solid dispersions. The complex is suitable for sterilization, such as by
gamma
irradiation or electron beam irradiation, prior to administration in vivo.
Preferred carrier
macromolecules for use in the complex are anionic polymers, such as anionic
polyalcohol derivatives, or fragments thereof, and salts thereof (e.g., sodium
salts).
Anionic moieties with which the polyalcohol can be derivatized include, for
example,
carboxylate, phosphate or sulfate groups. A particularly preferred anionic
polymer is an
anionic polysaccharide derivative, or fragment thereof, and salts thereof
(e.g., sodium
salts). The carrier macromolecule may comprise a single molecular species
(e.g., a
single type of polymer) or two or more different molecular species (e.g., a
mixture of
two types of polymers). Examples of specific anionic polymers include
carboxymethylcellulose, algin, alginate, anionic acetate polymers, anionic
acrylic
polymers, xantham gums, sodium starch glycolate, and fragments, derivatives
and
pharmaceutically acceptable salts thereof, as well as anionic carageenan
derivatives,
anionic polygalacturonic acid derivatives, and sulfated and sulfonated
polystyrene
derivatives. A preferred anionic polymer is carboxymethylcellulose sodium
salt. In
certain embodiments, the carrier macromolecule, preferably
carboxymethylcellulose
sodium, and the LHRH antagonist, preferably PPI-149, are combined at a ratio
of 0.2:1
(w/w) of carrier macromolecule:peptidic compound. In various other
embodiments, the
ratio of carrier macromolecule to peptidic compound (w/w) can be, for example,
0.5:1,
0.4:1, 0.3:1, 0.25:1, 0.15:1 or 0.1:1. In other preferred embodiments, the
peptide content
of the solid ionic complex of the LHRH antagonist and the carrier
macromolecule is
57%, 60%, 65%, 70%, 75%, 79%, or more by weight. In yet other preferred
embodiments, the peptide content of the solid ionic complex of the LHRH
antagonist
and the carrier macromolecule is 57 to 79% by weight. This formulation of the
LHRH
antagonist and a carrier macromolecule has the additional advantage that it
provides
sustained delivery of the LHRH antagonist into the tissue of the subject to
which it is
administered.
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In another embodiment, the pharmaceutically acceptable formulation comprises a
polymeric matrix. The terms "polymer" or "polymeric" are art-recognized and
include a
structural framework comprised of repeating monomer units. The terms also
include co-
polymers and homopalymers e.g., synthetic or naturally occurring. Linear
polymers,
branched polymers, and cross-linked polymers are also meant to be included.
For
example, polymeric materials suitable for forming the pharmaceutically
acceptable
formulation employed in the present invention, include naturally derived
polymers such
as albumin, alginate, cellulose derivatives, collagen, fibrin, gelatin, and
polysaccharides,
as well as synthetic polymers such as polyesters (PLA, PLGA), polyethylene
glycol,
poloxomers, polyanhydrides, and pluronics. These polymers are biocompatible,
biodegradable without producing any toxic byproducts of degradation, and they
possess
the ability to modify the manner and duration of LHRH antagonist release by
manipulating the polymer's kinetic characteristics. As used herein, the term
"biodegradable" means that the polymer will degrade over time by the action of
enzymes, by hydrolytic action and/or by other similar mechanisms in the body
of the
subject. As used herein, the term "biocompatible" means that the polymer is
compatible
with a living tissue or a living organism by not being toxic or injurious and
by not
causing an immunological rejection.
Polymers can be prepared using methods known in the art (Sandler, S. R.; Karo,
W. Polymer Syntheses; Harcourt Brace: Boston, 1994; Shalaby, W.; Ikada, Y.;
Larger,
R.; Williams, J. Polymers of Biological and Biomedical Significance (ACS
Symposium
Series 540; American Chemical Society: Washington, DC, 1994). Polymers can be
designed to be flexible; the distance between the bioactive side-chains and
the length of
a linker between the polymer backbone and the group can be controlled. Other
suitable
polymers and methods for their preparation are described in U.S. Patents
5,455,044 and
5,576,018.
The polymeric formulations can be formed, for example, by dispersion of the
active ingredient (e.g., the LHRH antagonist) within liquefied polymer, as
described in
U.S. Patent 4,883,666, or by such methods as bulk polymerization, interfacial
polymerization, solution polymerization and ring polymerization as described
in Odian
G., Principles of Polymerization and ring opening polymerization, 2nd ed.,
John Wiley
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& Sons, New York, 1981. The properties and characteristics of the formulations
are
controlled by varying such parameters as the reaction temperature,
concentrations of
polymer and LHRH antagonist, types of solvent used, and reaction times.
The LHRH antagonist can be encapsulated in one or more pharmaceutically
acceptable polymers, to form a microcapsule, microsphere, or microparticle,
terms used
herein interchangeably. Microcapsules, microspheres, and microparticles are
conventionally free-flowing powders consisting of spherical particles of 2
millimeters or
less in diameter, usually S00 microns or less in diameter. Particles less than
1 micron
are conventionally referred to as nanocapsules, nanoparticles or nanospheres.
For the
most part, the difference between a microcapsule and a nanocapsule, a
microsphere and a
nanosphere, or microparticle and nanoparticle is size; generally there is
little, if any,
difference between the internal structure of the two.
In another embodiment, the pharmaceutically acceptable formulations comprise
lipid-based formulations. Any of the known lipid-based drug delivery systems
can be
used in the practice of the invention. For instance, multivesicular liposomes
(MVL),
multilamellar liposomes (also known as multilamellar vesicles or "MLV"),
unilamellar
liposomes, including small unilamellar liposomes (also known as unilamellar
vesicles or
"SUV") and large unilamellar liposomes (also known as Iarge unilamellar
vesicles or
"LUV"), can all be used so long as a sustained release rate of the
encapsulated LHRH
antagonist can be established. In one embodiment, the lipid-based formulation
can be a
multivesicular liposome system. Methods of making controlled release
multivesicular
liposome drug delivery systems are described in Applications WO 9513796 and WO
9703652.
The composition of the synthetic membrane vesicle is usually a combination of
phospholipids, usually in combination with steroids, especially cholesterol.
Other
phospholipids or other lipids may also be used. Examples of lipids useful in
synthetic
membrane vesicle production include phosphatidylglycerols,
phosphatidylcholines,
phosphatidylserines, phosphatidylethanolamines, sphingolipids, cerebrosides,
and
gangliosides. Preferably phospholipids including egg phosphatidylcholine,
dipalmitoylphosphatidylcholine, distearoylphosphatidylcholine,
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dioleoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, and
dioleoylphosphatidylglycerol are used.
In preparing lipid-based vesicles containing an LHRH antagonist, such
variables
as the efficiency of the LHRH antagonist encapsulation, lability of the LHRH
antagonist, homogeneity and size of the resulting population of vesicles, LHRH
antagonist-to-lipid ratio, permeability, instability of the preparation, and
pharmaceutical
acceptability of the formulation should be considered (see Szoka, et al.,
Annual Reviews
of Biophysics and Bioengineering, 9:467, 1980; Deamer, et al., in Liposomes,
Marcel
Dekker, New York, 1983, 27; and Hope, et al., Chem. Phys. Lipids, 40:89,
1986).
Other formulations include controlled-release compositions (as referred to as
"sustained release formulations) such as are known in the art for the
administration of
leuprolide (trade name: Lupron~), e.g., microcapsules (U.S. Patents 4,652,441
and
4,917,893), injectable formulations (U.S. Patent 4,849,228), lactic acid-
glycolic acid
copolymers useful in making microcapsules or injectable formulations (U.S.
Patents
4,677,191 and 4,728,721), and sustained-release compositions for water-soluble
polypeptides (U.S. Patent 4,675,189). A particularly preferred sustained
release
formulation comprises the LHRH antagonist in a water-insoluble complex with an
anionic carrier macromolecule (described further above and in U.S. Application
Serial
No. 08/762,747 and PCT Application PCT/US97/22881).
In addition to the LHRH antagonist and a pharmaceutically acceptable carrier,
the pharmaceutically acceptable formulation used in the method of the
invention can
comprise additional pharmaceutically acceptable reagents and/or excipients. As
used
herein, "pharmaceutically acceptable reagent and/or excipient" is intended to
include any
and all solvents, dispersion media, coatings, antibacterial and anti fungal
agents, isotonic
agents (e.g., sugars, polyalcohols such as mannitol, sorbitol, or sodium
chloride) and
absorption delaying agents (e.g., monostearate salts and gelatin), and the
like that are
physiologically compatible. Excipients include pharmaceutically acceptable
stabilizers
and disintegrants. The proper fluidity can be maintained, for example, by the
use of a
coating such as lecithin, by the maintenance of the required particle size in
the case of
dispersion and by the use of surfactants. Except insofar as any conventional
media or
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agent is incompatible with the active compound (e.g., the LHRH antagonist) use
thereof
in the pharmaceutical compositions of the invention is contemplated.
Administration of the Pharmaceutically Acceptable Formulation
The LHRH antagonist can be administered as needed to a subject and preferably
is administered continuously using a sustained-release formulation, such as a
formulation comprising a water-insoluble complex of the LHRH antagonist and an
anionic carrier macromolecule, a slow-release polymer (e.g., a poly-lactide
polymer, a
poly-glycolide polymer and a poly-lactide/poly-glycolide copolymer), a
formulation in
an osmotic pump, an implant or a transdermal patch. The sustained release
formulation
is administered by an appropriate route for continual release of the drug in
the subject,
such as subcutaneous injection or implantation. The pharmaceutically
acceptable
formulations can easily be suspended in aqueous vehicles and introduced
through
conventional hypodermic needles or using infusion pumps. Prior to
introduction, the
formulations can be sterilized with, preferably, gamma radiation or electron
beam
sterilization, described in U.S. Patent 436,742. For injection, the LHRH
antagonist
formulation can be formulated in liquid solutions, preferably in
physiologically
compatible buffers such as Hank's solution or Ringer's solution. In addition,
the LHRH
antagonist formulation may be formulated in solid form, e.g., lyophilized, and
re-
dissolved or suspended immediately prior to use. The injection can be, for
example, in
the form of a bolus injection or continuous infusion (e.g., using infusion
pumps) ofthe
LHRH antagonist formulation.
When appropriately formulated, an LHRH antagonist may be orally
administered, for example, with an inert diluent or an assimilable edible
carrier. The
LHRH antagonist (and other ingredients) may also be enclosed in a hard or soft
shell
gelatin capsule, compressed into tablets, or incorporated directly into the
subject's diet.
For oral therapeutic administration, the LHRH antagonist may be incorporated
with
excipients and used in the form of ingestible tablets, buccal tablets,
troches, capsules,
elixirs, suspensions, syrups, wafers, and the like. The percentage of the LHRH
antagonist in the compositions and preparations may, of course, be varied. The
amount
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of the LHRH antagonist in such therapeutically useful compositions is such
that a
suitable dosage will be obtained.
To administer an LHRH antagonist by other than parenteral administration, it
may be necessary to coat the compound with, or co-administer the compound
with, a
material to prevent its inactivation.
In one embodiment of the methods of the invention, an LHRH antagonist
(typically in a pharmaceutical formulation) alone is administered to the
subject. In
another embodiment, the methods of the invention can involve administration of
an
LHRH antagonist in combination with one or more other therapeutic agents.
Examples
I 0 of other therapeutic agents, which can be combined with the LHRH
antagonist treatment
include antiestrogens (e.g., used in treatment of estrogen-dependent tumors,
or in the
treatment of gynaecomastia), anti-androgens, LHItH agonists or inhibitors of
sex steroid
biosynthesis. When an inhibitor of adrenal sex steroid biosynthesis is
employed, it may
be desirable to simultaneously administer hydrocortisone to the patient in an
amount
sufficient to maintain normal glucocorticoid levels.
Duration and Levels of Administration
In another embodiment of the invention, the pharmaceutically acceptable
formulation provides sustained delivery, e.g., "slow release" of the LHRH
antagonist to
a subject. Preferably, the formulation provides sustained delivery of the LHRH
antagonist for at least one week, more preferably at least two weeks and even
more
preferably at least one month after the pharmaceutically acceptable
formulation is
administered to the subject. In various embodiments, a subject may be treated
for at
least one month, at least three months or at least six months with the LHRH
antagonist.
As used herein, the term "sustained delivery" is intended to include continual
delivery of an LHRI-I antagonist in vivo over a period of time following
administration.
Sustained delivery of the LHRH antagonist can be demonstrated by, for example,
the
continued therapeutic effect of the LHI2I-I antagonist over time (e.g.,
sustained delivery
of the LHRH antagonist can be demonstrated by continued suppression of hot
flashes or
gynaecomastia over time). Alternatively, sustained delivery of the LHRH
antagonist
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may be demonstrated by detecting the presence of the LHRH antagonist in vivo
over
time.
The pharmaceutical formulation, used in the method of the invention, contains
a
therapeutically effective amount of the LHRH antagonist. A "therapeutically
effective
S amount" refers to an amount effective, at dosages and for periods of time
necessary, to
achieve the desired result. A therapeutically effective amount of the LHRH
antagonist
may vary according to factors such as the disease state, age, and weight of
the subject, and
the ability of the LHRH antagonist (alone or in combination with one or more
other
therapeutic agents) to elicit a desired response in the subject. Dosage
regimens may be
adjusted to provide the optimum therapeutic response. A therapeutically
effective amount
is also one in which any toxic or detrimental effects of the LHRH antagonist
are
outweighed by the therapeutically beneficial effects. A non-limiting range for
a
therapeutically effective amount of an LHRH antagonist is 0.01 pg/kg-10 mg/kg,
preferably between about 0.01 and 5 mg/kg. In preferred embodiments, the
dosage of
LHRH antagonist is about 15-300 pg/kg/day, more preferably about I S-200
p,g/kg/day and
even more preferably about IS-100 p.g/kg/day. Preferred dosages include 30
pg/kg/day,
50 p,g/kg/day, or 100 p,g/kg/day. It is to be noted that dosage values may
vary with the
severity of the condition to be alleviated. It is to be further understood
that for any
particular subject, specific dosage regimens should be adjusted over time
according to the
individual need and the professional judgment of the person administering or
supervising
the administration of the LHRH antagonist and that dosage ranges set forth
herein are
exemplary only and are not intended to limit the scope or practice of the
claimed
invention.
Dosage regimens may be adjusted to provide the optimum therapeutic response.
For example, a single bolus may be administered, several divided doses may be
administered over time or the dose may be proportionally reduced or increased
as
indicated by the exigencies of the therapeutic situation. It is especially
advantageous to
formulate parenteral compositions in dosage unit form for ease of
administration and
uniformity of dosage. "Dosage unit form" as used herein refers to physically
discrete
units suited as unitary dosages for the mammalian subjects to be treated; each
unit
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containing a predetermined quantity of the LHRH antagonist calculated to
produce the
desired therapeutic effect in association with the required pharmaceutical
carrier. The
specification for the dosage unit forms of the invention are dictated by and
directly
dependent on (a) the unique characteristics of the specific LHRH antagonist
used and the
particular therapeutic effect to be achieved, and (b) the limitations inherent
in the art of
compounding such an LHRH antagonist for the treatment of hot flashes or
gynaecomastia in a subject.
This invention is further illustrated by the following examples which should
not
be construed as limiting. The contents of all references, patents and
published patent
applications cited throughout this application are hereby incorporated by
reference.
EXAMPLES
EXAMPLE 1:
In this example, patients with stage D 1 or D2 metastatic prostate cancer or
patients with a rising Prostate Specific Antigen (PSA) level after radiation
therapy,
radical prostatectomy, or other local therapy were treated with the LHRH
antagonist
PPI-149 at a dosage of either 30 mg/kg/day or 50 mg/kg/day for a sustained
period of
time (e.g., 14 or 28 days). Other patients were treated with the LHRH agonist
leuprolide
or with both PP1-149 and leuprolide.
During the course of treatment, patients were asked to fill out an endocrine-
related questionnaire, which probed symptoms related to changes in androgenic
hormone
levels, including the occurrence of hot flashes. (Other symptoms probed
included
tiredness, loss of sexual desire, loss of sexual potency, smaller testicle
size, changes or
thinning in body hair, decrease in muscle mass, decrease in muscle tone,
increase or
decrease in body weight, urine frequency, urine urgency, urine hesitancy, and
nocturia.)
A summary of the results for the occurrence of hot flashes in patients treated
with either
PPI-149 alone, leuprolide alone or PPI-149 in combination with leuprolide are
summarized below:
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Treatment Regimen Occurence of Hot Flashes
PPI-149 alone 0/g
Leuprolide alone
PPI-149 + Leuprolide 3/8
This data demonstrates that patients treated with the LHRH antagonist PPI-149
alone did not experience hot flashes whereas more than half of the patients
treated with
the LHRH agonist leuprolide experienced hot flashes. Although not intending to
be
limited by mechanism, it is thought that the occurrence of hot flashes
results, at least in
part, from fluctuations in the levels of circulating luteinizing hormone (LH)
and/or
follicle stimulating hormone (FSH) and, accordingly, that use of an LHRH
antagonist
(which inhibits the activity of the LHRH receptor without causing minor surges
in the
levels of LH and/or FSH associated with the use of an LHRH agonist) can serve
to avoid
or inhibit these fluctuations in LH and/or FSH levels wherever they may occur
clinically
(e.g., in menopausal or postmenopausal women experiencing hot flashes or other
patient
population experiencing hot flashes).
EXAMPLE 2:
Patients with stage D 1 or D2 metastatic prostate cancer or patients with a
rising
Prostate Specific Antigen (PSA) level after radiation therapy, radical
prostatectomy, or
other local therapy, that were undergoing treatment with the LHRH antagonist
PPI-149
as described in Example 1, were questioned as to the occurrence of
gynaecomastia.
These results were compared to data obtained for patients treated with the
LHRH agonist
Leuprolide. The results demonstrated that the patients receiving treatment
with PPI-149
experienced gynaecomastia to a lesser extent than those treated with
leuprolide depot.
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EXAMPLE 3: '
To prepare a sustained release LHRH antagonist formulation, a 100 ml solution
of the LHRH antagonist PPI-149 was prepared by dissolving 6.25 mg/ml of PPI-
149 in
water. An equal sample ( 100 ml minimum) of USP carboxymethylcellulose sodium
(CMC) (low viscosity grade, Hercules Chemical Co.) was prepared at 0.125% w/v
and
mixed until dissolved. Equal portions of the PPI-149 and CMC solutions were
mixed
(giving a CMC:peptide ratio of 0.2:1 (w/w)) and a solid material was obtained.
The
solid material was stirred overnight and then collected by filtration over a
0.45 micron
nylon filter. HPLC evaluation of the solution filtrate indicated at least 95%
of the PPI-
149 compound was converted to the solid complex. was removed from solution.
The
recovered white paste was rinsed twice with water and then transferred to a
vial and
dried in vacuo. Upon drying for 72 hours, 633 mg of a white powder was
obtained. The
solid material was then powdered in a mortar and pestle. Elemental analysis
indicated
57% peptide in the complex.
EXAMPLE 4:
In this example, patients with stage D 1 or D2 metastatic prostate cancer or
patients with a rising Prostate Specific Antigen (PSA) level after radiation
therapy,
radical prostatectomy, or other local therapy were treated with the LHRH
antagonist
PPI-149 at a dosage of either 50 mg or 50-100 mg for a sustained period of
time (e.g., 4
weeks, 8 weeks, or 85 days). Other patients were treated with the LHRH agonist
leuprolide (LUPRONT"') with or without an anti-androgen.
During the course of treatment, patients were asked to fill out a
questionnaire,
which probed symptoms such as the frequency, severity, and duration of hot
flashes. A
summary of the results for the occurence of hot flashes in patients treated
for 4 weeks
with either PPI-149 alone, or leuprolide in combination with the anti-androgen
are
summarized below in Table I:
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Table I: Occurrence of Hot Flashes
Number of 0 1-4 5-> 10 p
hot
flashes/week
Leuprolide 43% 33% 26% .048
~
anti-androgen
(n=31 )
PPI-149 61 % 19% 20% .048
(n=199)
A summary of the results for the severity of hot flashes in patients treated
for 4
weeks with either PPI-149 alone, or leuprolide in combination with the anti-
androgen are
summarized below in Table II:
Table II: Severity of Hot Flashes
Severity 0 mild-moderatemoderate-severep
of hot
flashes
Leuprolide 42% 55% 3% .003
t
anti-androgen
(n=31)
PPI-149 62% 38% 0% .003
(n=199)
A summary of the results for the duration of hot flashes in patients treated
for 4
weeks with either PPI-149 alone, or leuprolide in combination with the anti-
androgen are
summarized below in Table III:
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Table III: Duration of Hot Flashes
Duration 0 minutes 0-2 minutes
of hot >_5 minutes p
flashes
Leuprolide 42% 32% 26% .003
~
anti-androgen
(n=31)
PPI-149 61 % 31 % 8% .003
(n=199)
These data demonstrate that during the first 4 weeks of treatment, patients
treated
with the LHRH antagonist PPI-149 alone experienced hot flashes less frequently
than
patients treated with leuprolide and anti-androgen. Moreover, the hot flashes
in patients
treated with PPI-149 alone were less severe and lasted for a shorter period of
time than
the hot flashes in patients treated with leuprolide and anti-androgen.
EQUIVALENTS
Those skilled in the art will recognize, or be able to ascertain using no more
than
routine experimentation, many equivalents to the specific embodiments of the
invention
described herein. Such equivalents are intended to be encompassed by the
following
claims.
