Hair loss abstract
Photodynamic therapy (PDT) is used to stimulate and/or restore
hair growth in areas of hair loss. Methods and compositions relating
to PDT treatment for alopecia are disclosed. In light of PDT use
to remove unwanted hair by inactivating or destroying hair follicles
or destroying the tissue feeding the hair follicles, such methods
and compositions relate to a surprising and unexpected discovery.
PDT permits a means to treat conditions relating to hair loss such
as androgenic alopecia, alopecia areata and drug-induced alopecia.
Hair loss claims
1. A method of stimulating hair growth on the skin of a subject
where hair loss has occurred, which method comprises administering
to the area of said skin where hair loss has occurred, an effective
amount of a BPD or green porphyrin photosensitizer for penetrating
into the area to result in a desired degree of biodistribution;
irradiating said area with light containing a wavelength of about
400 to about 900 nm and absorbed by said photosensitizer wherein
hair growth is stimulated in said area.
2. The method of claim 1 wherein said hair growth reduction or
hair loss is due to androgenetic alopecia, alopecia areata, drug-induced
alopecia, or radiation induced alopecia.
3. The method of claim 1, wherein said subject is human.
4. The method of claim 1 wherein said effective amount of a photosensitizer
is administered systemically at a dosage in the range of about 0.005
to about 10 mg/kg.
5. The method of claim 4 wherein said effective amount of a photosensitizer
is administered systemically at a dosage in the range of about 0.005
to about 2 mg/kg.
6. The method of claim 1 wherein said effective amount of a photosensitizer
is administered as an ointment containing about 0.001 to about 10%
7. The method of claim 6 wherein said effective amount of a photosensitizer
is administered as an ointment containing about 0.005 to about 5%
8. The method of claim 7 wherein said effective amount of a photosensitizer
is administered as an ointment containing about 0.05 to about 1%
9. The method of claim 8 wherein said effective amount of a photosensitizer
is administered as an ointment containing about 0.2% w/w photosensitizer.
10. The method of claim 1 wherein said administration is intravenously,
orally, subcutaneously, intramuscularly, intraperitoneally, intradermally,
topically, or by use of an implant.
11. The method of claim 1 wherein the BPD is BPD-MA, EA6, or B3.
12. The method of claim 1 wherein irradiation delivers a total
light dose of about 25, about 50, about 75, or about 100 J/cm.sup.2.
13. The method of claim 1 wherein the time between said administering
and irradiating is from about 5 minutes to about 6 hours.
14. The method of claim 13 wherein the time between said administering
and irradiating is from about 30 to about 120 minutes.
15. The method of claim 1 wherein said administering and irradiating
are repeated at least once.
16. A method of stimulating hair growth on the skin of an animal
or human being where hair loss has occurred, which method comprises
irradiating the area of said skin where hair loss has occurred,
after contacting said area with an effective amount of a BPD or
green porphyrin photosensitizer for penetrating into said area to
result in a desired degree of biodistribution, with light containing
a wavelength of about 400 to about 900 nm and absorbed by said photosensitizer
wherein hair growth is stimulated in said area.
Hair loss description
FIELD OF THE INVENTION
This invention relates to the use of photodynamic therapy (PDT)
and the use of PDT with appropriate photosensitizers to stimulate
hair growth. In particular, the use of photosensitizers and PDT
for treating conditions relating to hair loss, such as androgenetic
alopecia and alopecia areata, is described.
BACKGROUND OF THE INVENTION
Alopecia is the general term referring to any disease or condition
involving hair loss. There are several different types of hair loss,
the most common being androgenetic alopecia (AGA; see Sawaya, M.
E. Seminars in Cutaneous Medicine and Surgery 17(4):276 283, 1998),
alopecia areata (AA; see Fiedler & Alaiti, Dermatologic Clinics
14(4): 733 738, 1996, as well as drug-induced alopecia.
Androgenetic alopecia (AGA) is a patterned, progressive loss of
an excessive amount of hair from the scalp. Significant AGA occurs
in 50% of men by the age of fifty and 50% of women by the age of
sixty. AGA is believed to be a result of both genetic predisposition
and the presence of a sufficient level of circulating androgens.
It is thought that the enzyme 5 alpha reductase present in dermal
papilla cells converts testosterone to dihydrotestosterone (DHT).
DHT binds to androgen receptors, also localized in the dermal papilla
cells, triggering changes in the hair follicle that result in (1)
shortening of the anagen or growth phase of the hair cycle and lengthening
of the telogen or hair regeneraton stage, (2) development of a latent
phase in the hair cycle following shedding of the telogen hair,
and (3) follicular miniaturization that reduces the calibre of the
anagen hairs produced. It is thought that differential expression
of 5-alpha reductase and/or androgen receptors in various types
of hair follicles accounts for patterned hair loss.
The current treatments for AGA include minoxidil (Rogaine.TM.),
an anti-hypertensive drug for which the mechanism of action in promoting
hair growth is unknown. Minoxidil must be applied topically on a
daily basis, and is therefore somewhat inconvenient to use. Another
drug used in the treatment of AGA is finasteride (Propecia.TM.),
a selective inhibitor of the type 2 isoenzyme 5-alpha reductase.
This treatment has minimal efficacy, requires daily administration
and has some anti-androgenic side effects such as alteration of
libido. Hair transplants are also performed on the scalp of patients
with hair loss associated with AGA, but these are prohibitively
expensive for many people, and often require multiple time-consuming
sessions to complete.
Alopecia areata (AA) has been reported to account for 2% of new
outpatients in dermatology clinics (Fiedler & Alaiti supra).
AA is a nonscarring form of hair loss which occurs in humans and
other species and is thought to be due to an inflammatory reaction
caused by autoimmune response directed against the anagen stage
hair follicle structure (McElwee et al. Pathobiology 66(2): 90 107,
A number of therapeutic modalities have been tested for the treatment
of AA, with variable results ranging from no effect to partial or
full hair regrowth. In some cases chronic maintenance treatment
is required. Major drawbacks of these treatments are side effects,
which can be local or systemic in nature. Fiedler & Alaiti (supra)
and Shapiro (Dermatological Clinics 11(1): 35 46, 1993) have reviewed
the various treatments available for AA, including steroids (topical,
intralesional and systemic), minoxidil, anthralin, photochemotherapy,
cyclosporin A and other agents, as well as combination treatments.
Photochemotherapy therapy for AA using psoralen and high energy
UVA (PUVA) treatment has met with very limited success and its effectiveness
for AA is in doubt (Lebwohl, M. Lancet 349:222 223, 1997). Side
effects of PUVA treatment such as nausea, pigmentary changes, risk
of skin cancer formation, and cataracts have been reported (Fiedler
& Alaiti, supra). Antioxidants have been used to ameliorate
the side-effects of PUVA therapy (Ptapenko & Kyagova, Membr.
Cell Biol. 12(2): 269 278, 1998). The use of 2% khellin, a compound
with a chemical structure that resembles psoralen, and UVA for alopecia
areata was found to be successful in 5 of the 10 patients tested
(Orasa et al. Int. J. Dermatol. 32(9): 690, 1993). Since Khellin
did not cause phototoxicity, the authors have suggested its use
as an alternative to psoralen.
Hematoporphyrin and high energy UVA has been used in a very limited
study by Monfrcola et al. (Photodermatology 4:305 306, 1987). Two
patients were treated with topical hematoporphyrin (0.5%, HP) and
UVA irradiation with three times a week for eight weeks. In the
first week of treatment there was significant erythema and mild
scaling followed by hyperpigmentation in the HP treated sites. Side
effects included unpleasant reddish skin coloration for several
hours and sometimes burning sensations during the irradiation phase.
The authors point out that severe phototoxic reactions could occur
with the use of HP concentrations greater than 1%. They also state
that more work is needed before this approach can be subject to
routine clinical use.
Photodynamic therapy (PDT) has been utilized for the removal of
unwanted hair in human subjects. Briefly the treatment involves
a topical application of a photosensitizer on a selected area of
the skin, a period for absorption of the photosensitizer, followed
by a pulse or continuous irradiation or vibration of the area. The
process involves inactivating or destroying the hair follicles or
destroying the tissue feeding the hair follicles (see U.S. Pat.
Nos. 5,669,916; 5,871,480; WO 97/32046).
Photodynamic therapy is a minimally invasive two-step medical procedure
that uses light-activated drugs called photosensitizers to treat
a range of diseases involving rapid cell growth, such as cancerous
tumors or abnormal blood vessels. First, a photosensitizer is administered
and, once it has permeated the target tissue of interest, the photosensitizer
is then activated by exposure to a pre-calculated dose of light
at a particular wavelength. Once activated, the drug converts oxygen
found in the cells into highly energized singlet oxygen. Singlet
oxygen can react with subcellular components such as proteins and
lipids, which disrupts normal cellular function and results in killing
the cells. Lasers and fiber optics are used to deliver light.
There continues to be a need for a simple, rapid, and relatively
side effect free method for stimulating and/or restoring hair growth
in areas of hair loss.
Citation of the above documents is not intended as an admission
that any of the foregoing is pertinent prior art. All statements
as to the date or representation as to the contents of these documents
is based on the information available to the applicant and does
not constitute any admission as to the correctness of the dates
or contents of these documents.
SUMMARY OF THE INVENTION
It has been discovered that photodynamic therapy (PDT) can stimulate
hair growth and restore hair growth in areas of hair loss. In particular,
PDT using a unique class of photosensitizer known as green porphyrins
(Gp), in combination with irradiation, stimulates and/or restores
hair growth with no apparent side effects. In light of the use of
PDT to remove unwanted hair by inactivating or destroying hair follicles
or destroying the tissue feeding the hair follicles, as discussed
above, the instant invention relates to a surprising and unexpected
The instant invention also provides methods and compositions for
treating lack of hair growth or a reduction or loss of existing
hair by stimulating and/or restoring hair growth with PDT. Thus
one aspect of the invention relates to methods for stimulating,
inducing, restoring, reviving, renewing, replacing or otherwise
activating hair growth in animals characterized by a lack of hair
growth or a reduction in the amount of, or loss of, hair. In particular,
the treatment methods of the invention comprise i) administering
an effective and/or sufficient amount of photosensitizer resulting
in an effective or desired degree of biodistribution; ii) irradiating
at least a portion of the external surface of the animal with light
including one or more wavelengths capable of activating said photosensitizer
for a time period sufficient to activate the photosensitizer. The
administrating and irradiating acts of (i) and (ii) may be repeated
as necessary or desired to result in a desired level of hair growth.
The desired therapeutic response of hair growth can also be accomplished
by the irradiation of skin, which has been treated with an effective
amount of a photosensitizer, with light including one or more wavelengths
capable of activating said photosensitizer for a time period sufficient
to activate the photosensitizer and result in a desired level of
hair growth. Moreover, the methods of the invention may be practiced
with any photosensitizer, which may be delivered systemically or
In another aspect, the invention is directed to formulations or
compositions comprising photosensitizers for treating lack of hair
growth or a reduction or loss of existing hair with the methods
of the invention. The invention includes pharmaceutical compositions
targeted to hair follicles, the surrounding tissue, or tissues which
feed hair follicles. In particular, formulations comprising photosensitizers
conjugated to agents, which specifically target or bind appropriate
scalp or skin tissues, hair follicles, or tissues and cells surrounding
said hair follicles, are preferred for use in the methods of the
invention. Compositions comprising conjugated or unconjugated photosensitizers
are optionally formulated with agents suitable or preferred for
application to the scalp, or other skin where hair growth is desired.
Examples of such agents include pharmaceutically acceptable carriers
In addition to treatment of hair loss, the above described methods
and compositions may be used for the stimulation of hair growth
in areas not recognized as experiencing hair loss.
In preferred embodiments of the invention, the treatment methods
and compositions comprise the use of a particularly potent group
of photosensitizers known as green porphyrins, which are described
in detail in Levy et al., U.S. Pat. No. 5,171,749 issued 15 Dec.
1992, which is incorporated herein by reference. The term "green
porphyrins" refers to porphyrin derivatives obtained by reacting
a porphyrin nucleus with an alkyne in a Diels-Alder type reaction
to obtain a mono-hydrobenzoporphyrin. In particular, green porphyrin
compounds such as benzoporphyrin derivative mono-acid (BPD-MA),
EA6, and B3 may be used in the invention. Two preferred members
of the green porphyrin family are verteporfin (comprising the 4
enantiomers shown below) and QLT 0074.
##STR00001## ##STR00002## Additionally, the methods of the invention
preferably comprise irradiation with visible light absorbed by Gp.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows photographs taken over time of a representative untreated
control C57BL/6 mouse from an experiment examining the effect of
photodynamic therapy (PDT) treatment of mice with alopecia of unknown
etiology (Example 1). FIGS. 1.1 to 1.4 shows a control mouse with
a worsening of the alopecic condition over the experimental period
of 28 days.
FIG. 2 shows photographs taken over time of a representative PDT
treated C57BL/6 mouse from the experiment examining the effect of
PDT treatment on mice with alopecia of unknown etiology (Example
1). FIGS. 2.1 to 2.4 demonstrate that the PDT treatment over the
experimental period of 28 days resulted in impressive hair growth
in the alopecic patches.
FIG. 3 is a photograph of a representative control Balb/c mouse
that was shaved to remove hair, and subjected to a placebo PDT treatment
FIG. 4 is a photograph of a representative shaved Balb/c mouse
that was shaved to remove hair, and subjected to a PDT treatment
using the photosensitizer QLT 0074 (Example 2). Hair re-growth was
observed 17 days after PDT treatment.
Briefly stated, the invention provides methods and compositions
for stimulating hair growth utilizing photodynamic therapy (PDT)
treatment. For example, one aspect of the invention includes methods
for inducing or stimulating hair growth in animals characterized
by reduction or loss of hair. A sample method would comprise: (a)
administering an effective and/or sufficient amount of a photosensitizer
capable of penetrating into target skin to result in an effective
or desired degree of biodistribution; (b) irradiating the target
skin with light comprising one or more wavelength capable of activating
said photosensitizer for a time period sufficient to activate the
photosensitizer; and optionally (c) repeating (a) and (b) as necessary
or desired to elicit a desired level of hair growth. Such hair growth
would be the desired therapeutic response in the majority of cases.
PDT treatment of hair loss has the advantage that it obviates the
need for daily administration of a drug.
The present invention may be used with any subject, vertebrate
or invertebrate, capable of hair growth. Preferably, the invention
is applied to skin tissue exhibiting, or suspected of, hair growth
reduction or hair loss. Preferred subjects include mammals, with
human subjects being particularly preferred.
After administration, the photosensitizer will be present in hair
follicles and the surrounding tissues and cells for photoactivation.
Irradiation, preferably with light of appropriate wavelength and
intensity, will be applied using an appropriate light source, thereby
activating the photosensitizer to stimulate and/or restore hair
growth. By "stimulating" or "restoring" hair
growth, all manner of inducing, reviving, renewing, replacing or
otherwise activating hair growth are included. Preferably, the irradiation
is with visible light or comprises a wavelength of visible light.
The formulations and methods of the invention generally relate
to administering a photosensitizer, such as a green porphyrin, to
a subject undergoing PDT for alopecia. A "Green porphyrin"
(Gp) refers to a porphyrin derivative obtained by reacting a porphyrin
nucleus with an alkyne in a Diels-Alder type reaction to obtain
a mono-hydrobenzoporphyrin. Such resultant macropyrrolic compounds
are called benzoporphyrin derivatives (BPDs), which is a synthetic
chlorin-like porphyrin with various structural analogues, as shown
in U.S. Pat. No. 5,171,749. Typically, green porphyrins are selected
from a group of tetrapyrrolic porphyrin derivatives obtained by
Diels-Alder reactions of acetylene derivatives with protoporphyrin
under conditions that promote reaction at only one of the two available
conjugated, nonaromatic diene structures present in the protoporphyrin-IX
ring systems (rings A and B). Metallated forms of a Gp, in which
a metal cation replaces one or two hydrogens in the center of the
ring system, may also be used in the practice of the invention.
The preparation of the green porphyrin compounds useful in this
invention is described in detail in U.S. Pat. No. 5,095,030, which
is hereby incorporated by reference as if fully set forth.
Preferably, the BPD is a benzoporphyrin derivative di-acid (BPD-DA),
mono-acid ring A (BPD-MA), mono-acid ring B (BPD-MB), or mixtures
thereof. These compounds absorb light at about 692 nm wavelength
and have improved tissue penetration properties. The compounds of
formulas BPD-MA and BPD-MB may be homogeneous, in which only the
C ring carbalkoxyethyl or only the D ring carbalkoxyethyl would
be hydrolyzed, or may be mixtures of the C and D ring substituent
hydrolyzates. Some photosensitizers, such as phthalocyanines, may
be used in high concentrations sufficient to offset their relatively
slower uptake. An optimal photosensitizer for PDT treatment of alopecia
should be rapidly taken up by hair follicles and/or the surrounding
tissues and cells.
A particularly preferred photosensitizer formulation according
to the present invention will satisfy the following general criteria:
1) it is capable of rapid entry into the target hair follicles and/or
the surrounding tissues and cells; and 2) irradiation, preferably
with light (and more preferably with visible light), results in
the stimulation of and/or restoration of hair growth.
In one embodiment, the methods of the invention are used to stimulate
and/or restore hair growth after initial diagnosis. In another embodiment,
the methods of the invention follow other treatments for alopecia,
including PDT, as a form of maintenance therapy to prevent appreciable
hair loss and/or maintain hair growth. The latter may be used to
prevent or inhibit the re-occurrence of alopecia. PDT may be used
in conjunction with or in any combination with other treatments
for alopecia, for example, such as Rogaine.TM., Propecia.TM. or
hair transplants. For example, a patient may receive one or several
PDT treatments, but also use Rogaine.TM. or Propecia.TM. as recommended.
The methods of the invention can be used to stimulate hair growth
in any situation in which additional hair growth is desired. In
particular, the methods of the invention will be useful when the
subject has experienced loss of hair associated with a variety of
conditions, including, but not limited to the following: anagen
effluvium, drug-induced alopecia, radiotherapy, poisoning, diffuse
alopecia areata, alopecia areata, loose anagen syndrome, postoperative
occipital alopecia, syphilis, traction alopecia, tricholtillomania
tinea capitis, telogen effluvium, telogen gravidarum, chronic telogen
effluvium, early androgenentic alopecia, iron deficiency, malnutrition/malabsorption,
hypothyroidism, hyperthyroidism, systemic lupus erythematosus, chronic
renal failure, hepatic failure, advanced malignancy, viral or bacterial
infection and androgenetic alopecia. In particular, the methods
of the invention are useful for restoration of hair loss in androgenetic
alopecia, alopecia areata, drug-induced alopecia (for example following
chemotherapy treatment for cancer) and hair loss due to radiation
If the condition being treated is alopecia areata, preferably the
photosensitizer pro-drug 5-ALA is not used for topical administration
unless combined with at least one penetration enhancer that promotes
the distribution of the drug within the hair follicles.
After administration of the photosensitizer, sufficient time is
permitted to elapse for the compound to be taken up by the hair
follicles and/or the surrounding tissues and cells. This time for
uptake may be varied according to various parameters, including
but not limited to the photosensitizer administered, the route of
administration, the physiology of the subject and of the tumor cells,
and the artisan's skill and experience. With green porphyrins, for
example, the elapsed time may be from less than about one minute
to more than three hours, preferably from one minute to three hours,
and more preferably from 10 to 60 minutes. The cells, or tissues
containing them, are then irradiated at the wavelength of maximum
absorbance of the photosensitizer. In the case of BPDs, the wavelength
is usually between about 550 and 700 nm, as discussed above. In
particular, red light is advantageous because of its relatively
lower energy and the resulting lack of toxicity it poses to normal
The compositions and methods of the present invention provide a
useful PDT treatment to treat, and/or prevent or inhibit re-occurrence
of, alopecia. The following describes exemplary photosensitizers,
compositions and formulations of the present invention and their
clinical application. Experimental data also are presented and described.
The methods of the invention may be practiced with a variety of
photosensitizers. In addition to the above mentioned compounds,
additional examples of photosensitizers useful in the invention
for treatment of alopecia include, but are not limited to, green
porphyrins disclosed in U.S. Pat. Nos. 5,283,255, 4,920,143, 4,883,790,
5,095,030, and 5,171,749; and green porphyrin derivatives, discussed
in U.S. Pat. No. 5,880,145 and related U.S. patent application Ser.
No. 09/265,245. Several structures of typical green porphyrins are
shown in the above-cited patents, which also provide details for
the production of the compounds. The invention may be practiced
with a variety of synthetic and naturally occurring photosensitizers,
including pro-drugs such as 5-aminolevulinic acid, porphyrins and
porphyrin derivatives e.g. chlorins, bacteriochlorins, isobacteriochlorins,
phthalocyanine and naphthalocyanines and other tetra- and poly-macrocyclic
compounds, and related compounds (e.g. pyropheophorbides, sapphyrins
and texaphyrins) and metal complexes (such as, but not limited by,
tin, aluminum, zinc, lutetium). Tetrahydrochlorins, purpurins, porphycenes,
and phenothiaziniums are also within the scope of the invention.
Particularly preferred photosensitizers include green porphyrins
such as BPD-MA, EA6 and B3. Generally, any polypyrrolic or tetrapyrrolic
macrocyclic photosensitive compound that is hydrophobic can be used
in the invention. Examples of these and other photosensitizers for
use in the present invention include, but are not limited to, angelicins,
some biological macromolecules such as lipofuscin; photosystem II
reaction centers; and D1-D2-cyt b-559 photosystem II reaction centers,
chalcogenapyrillium dyes, chlorins, chlorophylls, coumarins, cyanines,
ceratin DNA and related compounds, certain drugs such as adriamycin;
afloqualone; amodiaquine; daunomycin; daunomycinone, certain flavins
riboflavins, fullerenes, metalloporphyrins, metallophthalocyanines,
methylene blue derivatives, naphthalimides, naphthalocyanines, certain
natural compounds such as kynurenines; sanguinarine; berberine;
carmane; and 5,7,9(11),22-ergostatetraene-3 .beta.-ol, nile blue
derivatives, NSAIDs (nonsteroidal anti-inflammatory drugs), perylenequinones,
phenols, pheophorbides, pheophytins, photosensitizer dimers and
conjugates, phthalocyanines, porphycenes, porphyrins, psoralens,
purpurins, quinones, retinoids, rhodamines, thiophenes, verdins,
vitamins and xanthene dyes (Redmond and Gamlin, Photochem. Photobiol.,
70(4):391 475 (1999)).
Exemplary angelicins include those modified by aceto or methyl
groups at the 3, 4', 4, 5', and/or 6 positions.
Exemplary chalcogenapyrillium dyes include pyrilium, selenopyrilium,
thiopyrilium and telluropyrilium perchlorates.
Exemplary chlorins dyes include 5-azachlorin dimethyl ester derivative;
5,10,15,20-tetrakis-(m-hydroxyphenyl) bacteriochlorin; benzoporphyrin
derivative monoacid ring A; benzoporphyrin derivative monoacid ring-A;
porphine-2,18-dipropanoic acid, 7-[2-dimethyl-amino)-2-oxoethyl]-8-ethylidene-7,8-dihydro-3,7,12,17-tetra-
methyl, dimethylester; porphine-2,18-dipropanoic acid, 7-[2-dimethyl-amino)-2-oxoethyl]-8-ethylidene-8-ethyl-7,8-dihydro-3,7,12,-
17-tetramethyl, dimethylester Z; porphine-2,18-dipropanoic acid,
17-tetramethyl, dimethylester Z ECHL; porphine-2,18-dipropanoic
12,17-tetramethyl, dimethylester Z; tin (II) porphine-2,18 -dipropanoic
o-3,7,12,17-tetramethyl, dimethylester Z; chlorin e.sub.6; chlorin
e.sub.6 dimethyl ester; chlorin e.sub.6 k.sub.3; chlorin e.sub.6
monomethyl ester; chlorin e.sub.6 Na.sub.3; chlorin p.sub.6; chlorin
p.sub.6-trimethylester; chlorin derivative zinc (II) porphine-2,18-dipropanoic
12,17-tetramethyl, dimethylester Z; 13.sup.1-deoxy-20-formyl-vic-dihydroxy-bacteriochlorin
di-tert-butyl aspartate; 13.sup.1-deoxy-20-formyl-4-keto-bacteriochlorin
di-tert-butyl aspartate; di-L-aspartyl chlorin e.sub.6; mesochlorin;
5,10,15,20-tetrakis-(m-hydroxyphenyl) chlorin; meta-(tetrahydroxyphenyl)chlorin;
chlorin e.sub.6; photoprotoporphyrin IX dimethyl ester; phycocyanobilin
dimethyl ester; protochlorophyllide a; tin (IV) chlorin e.sub.6;
tin chlorin e.sub.6; tin L-aspartyl chlorin e.sub.6; tin octaethyl-benzochlorin;
tin (IV) chlorin; zinc chlorin e.sub.6; and zinc L-aspartyl chlorin
Exemplary chlorophylls dyes include chlorophylls a and b; bacteriochlorophylls
a, b, c, or d; protochlorophylls; and amphiphilic derivatives thereof
Exemplary coumarins include methoxycoumarins; thenoylcoumarins;
khellin; RG 708; RG277; and visnagin.
Exemplary cyanines include benzoselenazole dye; benzoxazole dye;
oxacarbocyanines; thiacarbocyanines; selenacarbocyanines; kryptocyanine;
benzoxazole derivatives; quinoline derivatives; and merocyanines.
Exemplary fullerenes include C.sub.60; C.sub.70; C.sub.76; dihydro-fullerenes;
buckminster-fullerenes; and tetrahydro fullerenes.
Exemplary metalloporphyrins include chlorotexaphyrin nitrates;
cadmium or cobalt or copper or Europium or gallium or lutetium or
magnesium or manganese or nickel or palladium or platinum or samarium
or silver or tin or zinc porphyrins, tetrabenzoporphyrins, porphines,
texaphyrins, hematoporphyrins, tetrabenzoporphyrins, tetraphenylporphyrins,
chlorotexaphyrins, porphyrazines; zinc protoporphyrin; and zinc
Exemplary metallophthalocyanines include aluminum chloroaluminum
cobalt or copper or dichlorosilicon or gallium or germanium or lead
or magnesium or nickel or palladium or ruthenium or silicon or tin
or vanadium phthalocyanines (optionally sulfonates, disulfonates,
trisulfonates, and tetrasulfonates).
Exemplary naphthalimides blue derivatives include N,N'-bis-(hydroperoxy-2-methoxyethyl)-1,4,5,8-naphthaldiimide;
N,N'-bis(2,2-dimethoxyethyl)-1,4,5,8-naphthaldiimide; and N,N'-bis(2,2-dimethylpropyl)-1,4,5,8-naphthaldiimide.
Exemplary naphthalocyanines include aluminum or silicon or zinc
Naphthalocyanines, chloronaphthalocyanines, t-butylnaphthalocyanines,
amidonaphthalocyanines, tetraaminonaphthalocyanines, tetrabenzamidonaphthalocyanines,
tetramethoxynaphthalocyanines, naphthalocyanine tetrasulfonates
Exemplary nile blue derivatives include benzo[a]phenothiaziniums.
Exemplary perylenequinones include hypericins, calphostin C, cercosporins,
elsinochromes, phleichromes and rubellin A.
Exemplary phenols include 2-benzylphenol; 2,2'-dihydroxybiphenyl;
2,5-dihydroxybiphenyl; 2-hydroxybiphenyl; 2-methoxybiphenyl; and
Exemplary pheophorbides include pheophorbide a; methyl 13.sup.1-deoxy-20-formyl-7,8-vic-dihydro-bacterio-meso-pheophorbide
a; methyl-2-(1-dodecyloxyethyl)-2-devinyl-pyropheophorbide a; methyl-2-(1-heptyl-oxyethyl)-2-devinyl-pyropheophorbide
a; methyl-2-(1-hexyl-oxyethyl)-2-devinyl-pyropheophorbide a; methyl-2-(1-methoxy-ethyl)-2-devinyl-pyropheophorbide
a; methyl-2-(1-pentyl-oxyethyl)-2-devinyl-pyropheophorbide a; magnesium
methyl bacteriopheophorbide d; methyl-bacteriopheophorbide d; and
Exemplary pheophytins include bacteriopheophytin a; bacteriopheophytin
b; bacteriopheophytin c; bacteriopheophytin d; 10-hydroxy pheophytin
a; pheophytin; pheophytin a; and protopheophytin.
Exemplary porphyrins include 5-azaprotoporphyrin dimethylester;
bis-porphyrin; coproporphyrin III; coproporphyrin III tetramethylester;
deuteroporphyrin; deuteroporphyrin IX dimethylester; diformyldeuteroporphyrin
IX dimethylester; dodecaphenylporphyrin; hematoporphyrin; hematoporphyrin
IX; hematoporphyrin monomer; hematoporphyrin dimer; hematoporphyrin
derivatives; hematoporphyrin IX dihydrochloride; hematoporphyrin
IX dimethylester; mesoporphyrin dimethylester; monoformyl-monovinyl-deuteroporphyrin
IX dimethylester; monohydroxyethylvinyl deuteroporphyrin; 5,10,15,20-tetra(o-hydroxyphenyl)
porphyrin; 5,10,15,20-tetra(m-hydroxyphenyl) porphyrin; 5,10,15,20-tetrakis-(m-hydroxyphenyl)
porphyrin; 5,10,15,20-tetra(p-hydroxyphenyl) porphyrin; 5,10,15,20-tetrakis
(3-methoxyphenyl) porphyrin; 5,10,15,20-tetrakis (3,4-dimethoxyphenyl)
porphyrin; 5,10,15,20-tetrakis (3,5-dimethoxyphenyl) porphyrin;
5,10,15,20-tetrakis (3,4,5-trimethoxyphenyl) porphyrin; 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrin;
Photofrin.RTM.; Photofrin.RTM. II; porphyrin c; protoporphyrin;
protoporphyrin IX; protoporphyrin dimethylester; protoporphyrin
IX dimethylester; protoporphyrin propylaminoethylformamide iodide;
protoporphyrin N,N-dimethylaminopropylformamide; protoporphyrin
propylaminopropylformamide iodide; protoporphyrin butylformamide;
protoporphyrin N,N-dimethylamino-formamide; protoporphyrin formamide;
sapphyr tetrakis(4-sulfonatophenyl)porphyrin; meso-tetra(4-N-trimethylanilinium)-porphine;
uroporphyrin; uroporphyrin IX; and uroporphyrin I.
Exemplary psoralens include methoxypsoralens dimethoxypsoralens;
carbethoxypsoralens; pseudopsoralens; hydroxypsoralens; trimethylpsoralens;
allopsoralens; isopseudopsoralen; acetoisopseudopsoralens; pseudoisopsoralens;
Exemplary purpurins include octaethylpurpurin; octaethylpurpurin
zinc; oxidized octaethylpurpurin; reduced octaethylpurpurin; reduced
octaethylpurpurin tin; purpurin 18; purpurin-18; purpurin-18-methyl
ester; purpurin; tin ethyl etiopurpurin I; Zn(II) aetio-purpurin
ethyl ester; and zinc etiopurpurin.
Exemplary quinones include anthraquinones; benzoquinones; hydroquinones;
chlorohydroquinones; resorcinol; and 4-chlororesorcinol.
Exemplary retinoids include all-trans retinal; C.sub.17 aldehyde;
C.sub.22 aldehyde; 11-cis retinal; 13-cis retinal; retinal; and
Exemplary thiophenes include terthiophenes, bithiophenes, diphenylthiophene;
quaterthiophenes; .alpha.-quaterthienyl; .alpha.-tetrathiophene;
.alpha.-pentathiophene; .alpha.-hexathiophene; and .alpha.-heptathiophene.
Exemplary verdins include copro (II) verdin trimethyl ester; deuteroverdin
methyl ester; mesoverdin methyl ester; and zinc methyl pyroverdin.
Exemplary vitamins include ergosterol (provitamin D2); hexamethyl-Co
a Co b-dicyano-7-de(carboxymethyl)-7,8-didehydro-cobyrinate (Pyrocobester);
pyrocobester; and vitamin D3.
Exemplary xanthene dyes include cosins and eosin derivatives, erythrosins,
fluoresceins, phloxins, and rose bengals.
In one embodiment the preferred compounds for formulating are the
highly hydrophobic tetrapyrrolic A and B-ring compounds, such as
BPD-DA, -DB, -MA, and -MB. Most preferred are the B-ring compounds,
BPD-MB, B-EA6, B-B3; the A-ring compounds BPD-MA, A-EA6 and A-B3;
These compounds are porphyrin derivatives obtained by reacting
a porphyrin nucleus with an alkyne in a Diels-Alder type reaction
to obtain a monohydrobenzoporphyrin, and they are described in detail
in the issued U.S. Pat. No. 5,171,749, which is hereby incorporated
in its entirety by reference. Of course, combinations of photosensitizers
may also be used. It is preferred that the absorption spectrum of
the photosensitizer be in the visible range, typically between 350
nm and 1200 nm, more preferably between 400 900 nm, and even more
preferably between 600 900 nm.
BPD-MA is described, for example, in U.S. Pat. Nos. 5,171,749 and
5,095,030; EA6 and B3 are described in U.S. Pat. Nos. 5,929,105
and 5,880,145, respectively, all of which are incorporated herein
by reference. Preferred green porphyrins have the basic structure:
##STR00003## where R.sup.4 is vinyl or 1-hydroxyethyl and R.sup.1,
R.sup.2, and R.sup.3 are H or alkyl or substituted alkyl, and n
is an integer between 0 and 6, preferably 2.
BPD-MA (verteporfin) has the structure shown in formula 1 wherein
R.sup.1 and R.sup.2 are methyl, R.sup.4 is vinyl and one of R.sup.3
is H and the other is methyl, and n=2. B-EA6 is of formula 2 wherein
R.sup.1 and R2 are methyl and both R.sup.3 are 2-hydroxyethyl (i.e.,
the ethylene glycol esters). B3 is of formula 2 wherein R.sup.1
is methyl, R.sup.2 is H, and both R.sup.3 are methyl, and n=2. In
both EA6 and B3, R.sup.4 is also vinyl.
The representations of BPD-MA.sub.C and BPD-MA.sub.D, which are
the enantiomeric components of verteporfin, as well as illustrations
of A and B ring forms of EA6 and B3 (where n=2), are as follows:
Related compounds of formulas 3 and 4 are also useful; in general,
R.sup.4 will be vinyl or 1-hydroxyethyl and R.sup.1, R.sup.2, and
R.sup.3 are H or alkyl or substituted alkyl.
Additional examples of hydrophobic BPD B-ring compounds that are
difficult to formulate, and are especially well suited to use in
the invention are shown below. The compound QLT0069 is used in several
of the Examples herein.
TABLE-US-00001 ##STR00006## Drug X1 X2 X3 QLT0060 CO(O(CH.sub.2).sub.2)OH
CO(O(CH.sub.2).sub.2)OH COOCH.sub.3 QLT0069 COOCH.sub.3 COOCH.sub.3
COOH QLT0078 CO(O(CH.sub.2).sub.2).sub.2OH CO(O(CH.sub.2).sub.2).sub.2OH
COOCH.- sub.3 QLT0080 CO(O(CH.sub.2).sub.2).sub.3OH CO(O(CH.sub.2).sub.2).sub.3OH
COOCH.- sub.3 QLT0081 CO(O(CH.sub.2).sub.2).sub.2OCH.sub.3 CO(O(CH.sub.2).sub.2).sub.2OC-
H.sub.3 CO(O(CH.sub.2).sub.2).sub.2OCH.sub.3 QLT0082 CO(O(CH.sub.2).sub.2).sub.2OH
CO(O(CH.sub.2).sub.2).sub.2OH CO(O(C- H.sub.2).sub.2).sub.3OH QLT0083
CO(O(CH.sub.2).sub.2).sub.3OH CO(O(CH.sub.2).sub.2).sub.3OH CO(O(C-
H.sub.2).sub.2).sub.3OH QLT0087 CO(O(CH.sub.2).sub.2).sub.4OH CO(O(CH.sub.2).sub.2).sub.4OH
COOCH.- sub.3 QLT0088 COOCH.sub.3 COOCH.sub.3 CONH(C.sub.6H.sub.4)(C.sub.5H.sub.10N)
QLT0090 CO(O(CH.sub.2).sub.2).sub.5OH CO(O(CH.sub.2).sub.2).sub.5OH
COOCH.- sub.3 QLT0093 CO(O(CH.sub.2).sub.2).sub.5OH CO(O(CH.sub.2).sub.2).sub.5OH
Dimeric forms of the green porphyrin and dimeric or multimeric
forms of green porphyrin/porphyrin combinations may also be used.
The dimers and oligomeric compounds of the invention can be prepared
using reactions analogous to those for dimerization and oligomerization
of porphyrins per se. The green porphyrins or green porphyrin/porphyrin
linkages can be made directly, or porphyrins may be coupled, followed
by a Diels-Alder reaction of either or both terminal porphyrins
to convert them to the corresponding green porphyrins.
Other non-limiting examples of photosensitizers which may be useful
in the invention are photosensitizing Diels-Alder porphyrin derivatives,
described in U.S. Pat. No. 5,308,608; porphyrin-like compounds,
described in U.S. Pat. No. 5,405,957, 5,512,675, and 5,726,304;
bacteriochlorophyll-A derivatives described in U.S. Pat. Nos. 5,171,741
and 5,173,504; chlorins, isobacteriochlorins and bacteriochlorins,
as described in U.S. Pat. No. 5,831,088; meso-monoiodo-substituted
and meso substituted tripyrrane, described in U.S. Pat. No. 5,831,088;
polypyrrolic macrocycles from meso-substituted tripyrrane compounds,
described in U.S. Pat. Nos. 5,703,230, 5,883,246, and 5,919,923;
and ethylene glycol esters, described in U.S. Pat. No. 5,929,105.
All of the patents cited in this paragraph are hereby incorporated
by reference as if fully set forth. Generally any hydrophobic photosensitizers,
which absorb in the ultra-violet, visible and infra-red spectroscopic
ranges would be useful for practicing this invention.
Additionally, the photosensitizers used in the invention may be
conjugated to various ligands to facilitate targeting to hair follicles
or the surrounding tissues and cells. These ligands include those
that are receptor-specific as well as immunoglobulins and fragments
thereof Preferred ligands include antibodies in general and monoclonal
antibodies, as well as immunologically reactive fragments of both.
The photosensitizers of the invention may be administered as a
single compound or as a mixture of various photosensitizers. Suitable
formulations include those appropriate for administration of therapeutic
compounds in vivo. Additionally, other components may be incorporated
into such formulations. These include, for example, visible dyes
to facilitate visualization or imaging of the formulation or various
enzymes to facilitate the access of a photosensitizing compound
to target sites.
The photosensitizers of the invention may be formulated into a
variety of compositions. These compositions may also comprise further
components, such as conventional delivery vehicles and excipients
including isotonising agents, pH regulators, solvents, solubilizers,
dyes, gelling agents and thickeners and buffers and combinations
thereof. Appropriate formulations and dosages for the administration
of photosensitizers are known in the art. Suitable excipients for
use with photosensitizers include water, saline, dextrose, glycerol
and the like.
Typically, the photosensitizer is formulated by mixing it, at an
appropriate temperature, e.g., at ambient temperatures, and at appropriate
pHs, and the desired degree of purity, with one or more physiologically
acceptable carriers, i.e., carriers that are nontoxic at the dosages
and concentrations employed. Generally, the pH of the formulation
depends mainly on the particular use, and concentration of photosensitizer,
but preferably ranges anywhere from about 3 to about 8. Preferably,
the photosensitizer is maintained at a pH in the physiological range
(e.g., about 6.5 to about 7.5). The presence of salts is not necessary,
and, therefore the formulation preferably is not an electrolyte
The particular concentration of a given photosensitizer should
be adjusted according to its photosensitizing potency. For example,
BPD-DA can be used but at about a five-fold higher concentration
than that of BPD-MA. Moreover, the Gp may be solubilized in a different
manner than by formulation in liposomes. For example, stocks of
BPD-MA or any other Gp may be diluted in DMSO (dimethylsulfoxide),
polyethylene glycol (PEG) or any other solvent acceptable for use
in the treatment of skin tissues and cells. In some embodiments
of the invention the formulations will contain one or more PEGs
of different molecular weights. Formulations comprising at least
one PEG of less than about 2000, less than about 1500, less than
about 1000, less than about 800, less than about 600, less than
about 500, less than about 400, less than about 200, and less than
about 100 molecular weight are used in the formulations of the invention.
A second PEG of about 3000, about 3350, about 3500, or about 4000
or higher molecular weight may also be included.
Normally, the adjustment of pH is not required when liposomal formulations
are used, as both components have a neutral pH. However, when solvents
other than liposomes are used, the pH may require adjustment before
mixing the Gp with the other material.
Preparation of dry formulations that are reconstituted immediately
before use also are contemplated. The preparation of dry or lyophilized
formulations of the compositions of the present invention can also
be effected in a known manner, conveniently from the solutions of
the invention. The dry formulations of this invention are also storable.
By conventional techniques, a solution can be evaporated to dryness
under mild conditions, especially after the addition of solvents
for azeotropic removal of water, typically a mixture of toluene
and ethanol. The residue is thereafter conveniently dried, e.g.
for some hours in a drying oven.
Suitable isotonising agents are preferably nonionic isotonising
agents such as urea, glycerol, sorbitol, mannitol, aminoethanol
or propylene glycol as well as ionic isotonising agents such as
sodium chloride. The solutions of this invention will contain the
isotonising agent, if present, in an amount sufficient to bring
about the formation of an approximately isotonic solution. The expression
"an approximately isotonic solution" will be taken to
mean in this context a solution that has an osmolarity of about
300 milliosmol (mOsm), conveniently 300+10% mOsm. It should be borne
in mind that all components of the solution contribute to the osmolarity.
The nonionic isotonising agent, if present, is added in customary
amounts, i.e., preferably in amounts of about 1 to about 3.5 percent
by weight, preferably in amounts of about 1.5 to 3 percent by weight.
Solubilizers such as cremophor types, preferably Cremophor RH 40,
Transcutol.RTM., corn glycerides or Tween types or other customary
solubilisers, may be added to the solutions of the invention in
A further preferred embodiment of the invention relates to a solution
comprising a Gp, and a partially etherified cyclodextrin, the ether
substituents of which are hydroxyethyl, hydroxypropyl or dihydroxypropyl
groups, a nonionic isotonising agent, a buffer and an optional solvent.
However, appropriate cyclodextrins should be of a size and conformation
appropriate for use with the photosensitizing agents disclosed herein.
Summaries of pharmaceutical compositions suitable for use with
the instant photosensitizers are known in the art and are found,
for instance, in Remington's Pharmaceutical Sciences. Preferred
for the practice of the invention are pharmaceutical excipients
or carriers capable of directing the photosensitizer to the area
of hair growth reduction or hair loss. In the case of topical formulations
(including ointments), penetration enhancers such as Transcutol.RTM.
(diethylene glycol monoethyl ether) are highly desirable in order
to promote the distribution of photosensitizer in the hair follicle
and surrounding tissues. In particular if the condition being treated
is alopecia areata, preferably the photosensitizer pro-drug 5-ALA
or similar drugs are not used for topical administration unless
combined with at least one penetration enhancer that promotes the
distribution of the drug within the hair follicles and surrounding
Administration of Photosensitizers
As noted above, the treatment methods of the invention are targeted
to hair follicles and/or surrounding tissues and cells as a treatment
for alopecia. The photosensitizer containing preparations of the
invention may be administered systemically or locally and may be
used alone or as components of mixtures. The route of administration
for the photosensitizer may be topical, intravenous, oral, or by
use of an implant. For example green porphyrins may be administered
by means including, but not limited to, topical-preparations, intravenous
injection or infusion, oral intake, or local administration in the
form of intradermal injection or an implant. Additional routes of
administration are subcutaneous, intramuscular, or intraperitoneal
injections of the photosensitizers in conventional or convenient
In particular, liposomal or lipophilic formulations are most desirable,
and topical delivery of photosensitizers is preferred, while injection
may also be used when desired. For topical administration, the photosensitizers
may be in standard topical formulations and compositions including
lotions, suspensions or pastes. Oral administration of suitable
formulations may also be appropriate in those instances where the
photosensitizer may be readily administered to the hair follicle
and/or surrounding tissues or cells via this route. A preferred
method of administration is to apply the photosenisitizer topically
in an excipient containing solubilizing agent, such as Cremophor
or corn glycerides, and to wash the treatment area within about
an hour (such as, but not limited to, after about 10, about 15,
about 20, about 30, about 45, or about 60 minutes) with the excipient
to remove excess drug from the surface of the skin.
The dose of photosensitizers may be optimized by the skilled artisan
depending on factors such as, but not limited to, the photosensitizer
chosen, the physical delivery system in which it is carried, the
individual subject, and the judgment of the skilled practitioner.
It should be noted that the various parameters used for effective
PDT in the invention are interrelated. Therefore, the dose should
also be adjusted with respect to other parameters, for example,
fluence, irradiance, duration of the light used in PDT, and time
interval between administration of the dose and the therapeutic
irradiation. All of these parameters may be readily adjusted using
routine experimentation to produce a desired level of alopecia treatment
without causing significant damage to the surrounding tissue. With
photosensitizers, for example, the form of administration, such
as in liposomes or when coupled to a target-specific ligand, such
as an antibody or an immunologically active fragment thereof, is
one factor considered by a skilled artisan.
Depending on the specificity of the preparation, smaller or larger
doses of photosensitizers may be needed. For compositions which
are highly specific to the target skin tissues and cells, such as
those with the photosensitizer conjugated to a highly specific monoclonal
antibody preparation or specific receptor ligand, dosages in the
range of 0.005 10 mg/kg of body weight are suggested for systemic
administration. For compositions which are less specific to the
target, larger dosages, up to 1 20 mg/kg, may be desirable. The
potency of the photosensitizer also determines the dosage, with
less required for highly potent photosensitizers, and more for photosensitizers
with less potency. The preferred range for use in mice is from about
0.05 mg/kg to about 20 mg/kg. The useful range in humans for the
photosensitizer will be lower than mice, such as from about 0.005
mg/kg to about 4 mg/kg, and preferably from about 0.05 to about
For topical formulations (such as ointments) to be applied to the
surface of the skin, the concentration of the photosensitizer in
the excipient can range from about 0.001 to about 10% w/w, and more
preferably from about 0.005 to about 5% w/w (or about 0.05 to about
1% w/w), and even more preferably between about 0.1 to about 1%
w/w. Particularly preferred is the use of a 0.2% (or about 0.2)
w/w topical formulation. The foregoing ranges are merely suggestive
in that the number of variables with regard to an individual treatment
regime is large and considerable deviation from these values may
If the photosensitizer is a green porphyrin, topical formulations
to be applied to the skin containing in the range from about 0.005%
(w/w) to about 0.5% (w/w), are particularly preferred for stimulating
hair growth. Higher concentrations, in the range of about 0.5% (w/w)
to 5% may also be used, but have the disadvantage that they require
more green porphyrin to manufacture. Lower doses, in the range from
about 0.0005 to about 0.005 may also be used, but may require longer
irradiation treatment times. A topical formulation containing 0.2%
(w/w) of QLT 0074 was shown to be localized in human hair follicles
thirty minutes after application to human cadaver scalp skin.
The skilled artisan is free to vary the foregoing concentrations
so that the uptake and stimulation/restoration parameters are consistent
with the therapeutic objectives disclosed above. The concentration
of a particular photosensitizer to use in a topical formulation
can easily be determined by performing a dose ranging study similar
to the one outlined in the Examples below.
Each photosensitizer requires activation with an appropriate wavelength(s)
of radiation. As such, the methods of the invention may be conducted
with any irradiation, preferably with light, which activates the
photosensitizer used. Preferably, the irradiation contains one or
more wavelength which is capable of penetrating the skin to activate
the photosensitizer used. The wavelength(s) of radiation or light
useful in the invention depends on the activation range of the photosensitizer
used as part of the treatment method. Wavelengths of about 380 900
nanometers (nm) are preferred, depending upon the photosensitizer
and upon the depth of tissue penetration desired. More preferred
are wavelengths from about 400 to about 900 nm, most preferred from
about 400 to about 700 nm. For example, BPD-MA, a green porphyrin
derivative, can be activated by red and blue light as well as ambient
light containing wavelengths from 400 900 nm. Light having a wavelength
shorter than 400 nm is acceptable, but not preferred because of
the potentially damaging effects of UVA light.
An appropriate light source, preferably a laser or light emitting
diode (LED), in the range of about 550 to about 900 nm, depending
on the absorption spectrum of the photosensitizer, may be used for
photosensitizer activation An appropriate and preferred wavelength
for such a laser includes 690.+-.12.5 nm at half maximum when BPDs
are used. . Alternatively any convenient source of light having
a component of wavelengths that are absorbed by the photosensitizer
may be used, for example, an operating room lamp, or any bright
light source, including sunlight. Light wavelengths in the ultraviolet
range should, however, generally be avoided because of their mutagenic
potential. The light dose administered during the PDT treatment
contemplated herein can vary, and can range between about 0.1 to
about 200 J/cm.sup.2. Increases in irradiance will generally decrease
the light exposure times. Generally, a higher dose of photosensitizer
will decrease the light dose required to exert a therapeutic effect.
Normally, the intensity of the light source should not exceed about
600 1000 mW/cm.sup.2. Irradiances between about 50 and 400 mW/cm.sup.2,
and more preferably between 100 and 200 mW/cm.sup.2 are preferred.
The total dose of the irradiation should generally not exceed 200
J/cm.sup.2, and is preferably at or about 25, 50, 75, 100, 125,
150, or 175 J/cm.sup.2. Preferably, for photosensitizers of high
potency, such as green porphyrins the dosage of the light is about
5 50 J/cm.sup.2 for systemically-delivered drug and about 25 200
J/cm.sup.2 for topically-delivered photosensitizers. Normally, the
irradiation lasts from about 10 seconds to about 3 hours, and preferably
between about 5 minutes and 1 hour. Irradiation times of about 10,
about 15, about 20, about 30, about 45, about 60, about 75, about
90, about 105, about 120, about 135, about 150, about 165 and about
180 minutes may be used.
The irradiation or light exposure used in the invention may be
directed to a localized area, such as the eyebrow area of a human,
or to cover an extended portion of the body or scalp depending on
the alopecic patch to be treated. Treatment may be preceded with
an assessment of the time of light exposure for the patient's minimal
erythemal dose (MED) occurrence in order to avoid potential burning
of the exposed skin. Such treatments may be at a frequency of one
to three treatments on a weekly, biweekly, monthly, bimonthly, quarterly,
biannually, or annually, or other suitable time interval to stimulate
hair growth or to maintain the prevailing condition. In cases where
hair loss is observed, maintenance treatment on a regular basis
may be initiated and sustained.
The number of applications of PDT treatment may depend on the type
and the extent of alopecia condition as well as the experience of
those in the art and the condition of the subject. Preferably, the
PDT treatment is repeated at a frequency of 1, 2, 3, 4, 5, 6, or
12 times per 3 month period.
Light treatment can take place at any time following administration
of photosensitizer as long as the photosensitizer has not been completely
cleared from the skin. Light treatment within a period of about
five minutes to about 6 hours after administration of the photosensitizer
is generally preferred, with a range of 30 minutes to 2 hours being
especially preferred. Irradiation times of about 15, about 30, about
45, about 60, about 75, about 90, about 105, and about 120 minutes
may be used. The time between administration of photosensitizer
and administration of light will vary depending on the pharmacokinetics
of the photosensitizer used. Photosensitizers that rapidly accumulate
in target tissues can be activated soon after administration. Photosensitizers
that are cleared from tissues quickly should be activated soon after
accumulation in the target tissues.
Having now generally described the invention, the same will be
more readily understood through reference to the following examples
which are provided by way of illustration, and are not intended
to be limiting of the present invention, unless specified.
Photodynamic Therapy Treatment of C57BL/6 Mice with Alopecia of
C57BL/6 mice used in this example were purchased from Jackson Laboratories
(Bar Harbor, Me.). After 4 weeks of housing some of the C57BL/6
mice spontaneously developed a hair loss condition which resulted
in large bald patches (see FIG. 1.1) at 12 to 14 weeks of age. One
of these animals was sacrificed and skin samples were sent for histopathological
evaluation. The skin sample showed no evidence of infection according
to a veterinarian's histopathological examination. The condition
was diagnosed as alopecia of unknown etiology. The presence of an
undefined "mononuclear cell infiltrate" was noted within
the affected skin and, without being bound by theory, may indicate
an autoimmune etiology for alopecia in the mouse.
Eight mice that were developing hair loss were chosen. Four mice
were randomly picked for the PDT treatment while the remaining four
served as untreated controls. PDT consisted of intravenously injecting
vertporfin in a lipid-based formulation (Visudyne.RTM., Novartis
Opthalmics, Duluth, Ga.) at a dosage of 1 mg/kg of body weight per
mouse, followed by exposure to 690 nm wavelength red light at 15
J/cm.sup.2, delivered by an array of light emitting diode (LED)
panels, at 1 hour post-injection. (see Simkin G. et Al. 1997. Inhibition
of contact hypersensitivity with different analogs of benzoporphyrin
derivative. Immunopharmacology 37:221 230, which is incorporated
by reference as if fully set forth). This was followed by two additional
PDT treatments on days 7 and 14.
The mice were observed and photographed on days 0, 13, 21 and 28.
FIGS. 1 and 2 show a representative untreated control and a PDT
treated mouse photographed at day 0, day 13, day 21 and day 28.
There was no improvement in the alopecic patches in the untreated
control group of mice (n=4) and in fact, these patches worsened
over the time course of the experiment (FIGS. 1.1 to 1.4). In the
PDT treated group (n=4) there was a startling and impressive hair
growth observed in the alopecic patches after the first and second
treatments as demonstrated in FIGS. 2--2 and 2 3. By day 28, the
previously alopecic patches were covered with what appeared to be
a full complement of hair.
PDT-induced Stimulation of Hair Growth using Topically-applied
To prepare QLT 0074-containing ointment, QLT 0074 photosensitizer
was dissolved in glacial acetic acid to solubilize it. The solution
was then frozen in a dry ice/isopropanol bath and the acetic acid
was removed by lyophilization. The resultant material was a fine
fluffy powder. Analytical testing of the cryodessicated QLT 0074
indicated that the process did not cause degradation. The ointment
base was prepared by first warming polyethylene glycol 200 (PEG
200) to 80 90.degree. C. with stirring. Polyethylene glycol 3350
(PEG 3.35K) was then added with stirring, followed by oleyl alcohol,
and then diethylene glycol monoethyl ether. Stirring was continued
until the solution was clear. The ointment base was cooled to approximately
50.degree. C., and the QLT 0074 was added with stirring. Stirring
was continued as the mixture cooled, until a homogenous paste was
achieved. The ointment contained the following proportions of the
components on a weight/weight basis. QLT 0074 (1) PEG-200 (108)
diethylene glycol monoethyl ether Transcutol.RTM. (40) PEG-3.35K
(32) oleyl alcohol (20).
The concentration of QLT 0074 in the ointment was 0.5% weight/weight.
A placebo ointment was prepared which contained the excipients,
but lacked QLT 0074. The ointments were stored refrigerated at 2
to 8.degree. C. until use.
Female Balb/C mice (8 14 weeks old) were supplied by Charles River
Canada (St. Constance, Quebec). Mice were acclimated to laboratory
conditions for seven days prior to release from quarantine. Cages
of animals were held in enclosed ventilated animal racks in temperature
and humidity controlled rooms. Mice were kept on a standard diet
and water ad libitum in a 12 hours light/dark cycle. Mice were randomly
assigned to PDT treatment and controlled groups, and were monitored
for pain or distress.
Eighteen mice were shaved to remove hair from the back and both
flanks. The right side of each mouse served as a control, receiving
no light and no photosensitizer. QLT 0074-containing ointment was
applied to a square spot on the left side of each of mice 1 9 using
a square template, with the same quantity of ointment applied to
each spot. Placebo formulation was applied to a square spot on the
left side of each of mice 10 18 in the same manner. After 30 minutes,
the excess ointment was removed from the spots by washing with water
using a sterile gauze pad, and then placebo ointment was applied
to the same spots on each of mice 1 18. After 15 minutes, the spots
were irradiated with 50J/cm.sup.2 of light delivered at a fluence
rate of 200 mW/cm.sup.2. Light (688 nm +/-6 nm) was delivered from
a light emitting diode (LED) unit (Quantum, Model QB-Quanta-Med-688).
Out of the nine mice treated with QLT 0074, five developed hair
growth on the treated area by day 17. In contrast, none of the placebo-treated
mice developed hair regrowth on the area corresponding to the treatment
area during that period. A photograph showing hair regrowth on the
left side of a representative QLT 0074-treated mouse at day 17 is
shown in FIG. 4. A mouse treated with placebo is shown in FIG. 3.
Similar results were obtained in another experiment in which mice
were treated with the same formulation of 0.5% (w/w) QLT 0074, but
a higher light dose of 150 J/ cm.sup.2 was used.
Optimization of Irradiation Dose and Timing for Photodynamic Treatment
of Alopecia Areata after Intravenous Injection of Photosensitizer
This example examines the effect of different irradiation protocols
on PDT treatment of alopecic mice as described above.
Alopecic mice are divided into control and treatment groups. The
treatment mice are injected with verteporfin in a lipid-based formulation
at 1 mg/kg of body weight, and the control group are mock injected.
Mice from both groups are exposed to red light at the following
doses: 1, 2, 5, 10 and 20 J/cm.sup.2 light LED at 1 hour post-injection,
in a manner as described above in Example 1. Two additional PDT
treatments are administered on days 7 and 14 post photosensitizer
administration. All mice are monitored over a 5 week period, photographed
pre-treatment and on days 6, 13, 20, 27, and 34 post irradiation,
and with biopsies taken for histopathological analysis.
In a separate experiment, alopecic mice are divided into control
and treatment groups. The treatment mice are injected with verteporfin
at 1 mg/kg of body weight, and the control group are mock injected.
Mice from both groups are exposed to red light at 15 J/cm.sup.2
light LED at 15, 30 and 60 120 and 180 minutes post-injection, in
a manner as described above in Example 1. Two additional PDT treatments
are administered on days 7 and 14 post photosensitizer administration.
All mice are monitored over a 5 week period, photographed pre-treatment
and on days 6, 13, 20, 27, and 34 post irradiation, and with biopsies
taken for histopathological analysis.
Optimization of Drug Concentration, Irradiation Dose and Light
Intensity on Hair Regrowth in Mice using Topically-applied QLT-0074
A study was performed to assess the effect of drug concentration
(0.005, 0.05, or 0.5% QLT 0074 ointment), light dose (50, 100 or
150 J/cm.sup.2 red light) and light intensity 50 or 200 mW/cm.sup.2)
on hair regrowth in shaved female Balb/c mice. Mice received QLT
0074 ointment applied to the skin for 30 minutes, followed by a
15-minute treatment with placebo ointment and exposure to red light
(688 nm). One group received no QLT 0074 ointment, only the placebo
ointment and light exposure. Preparation of ointments and treatment
procedure was as outlined in Example 2, except that different amounts
of QLT 0074 were added.
Hair regrowth at the treatment site was observed in mice treated
with a QLT 0074 ointment doses of 0.5% combined with light doses
of 50, 100 or 150 J/cm.sup.2 at 200 mW/cm.sup.2. Hair regrowth at
the treatment site was also observed for mice treated with 0.5%
QLT 0074 ointment combined with either 50 or 100 J/cm.sup.2 red
light delivered at 50 mW/cm.sup.2. Animals treated with 0.05% QLT
0074 ointment did not exhibit hair growth at any light dose, but
hair regrowth at the treatment site was observed for one of three
animals treated with 0.005% QLT 0074 ointment and 150 J/cm.sup.2
delivered at 200 mW/cm.sup.2. No hair regrowth occurred in mice
that received placebo ointment only and were exposed to red light
at 200 mW/cm.sup.2.
Ointments were prepared as in Example 2, except that different
amounts of QLT 0074 (on a weight/weight basis) were incorporated
into the ointments. The treatment procedure was as outlined in Example
Mild skin reactions were evident following some treatments, typically
at the highest drug and light dose combinations, but no moderate
or severe skin photosensitivity reactions were observed.
Stimulation of Hair Growth in Human Subjects with AGA
Subjects exhibiting hair loss associated with AGA were administered
QLT 0074 in a topical ointment comprising 0.2% (weight/weight) of
QLT 0074, and the other excipients outlined in Example 2. Approximately
224 mg of ointment was applied per 5.1 cm.sup.2 of surface area,
providing about 0.44 mg of QLT 0074/cm.sup.2 of skin surface area.
Application of QLT 0074 was localized to regions of the scalp exhibiting
hair loss. The QLT 0074-containing ointment was left on for a period
of either 30 minutes or two hours. After application, excess ointment
was removed with a damp cloth. In some subjects, the vehicle ointment
was applied to the treatment area for five minutes and then removed
prior to irradiation. Irradiation was provided at a dose of 25,
50, 75 or 100 J/cm.sup.2, administered at a fluence rate of 50 mW/cm.sup.2.
These irradiation doses required exposure of the skin for a duration
of 8:20, 16:40, 25:00 and 33:20 (minutes:seconds), respectively.
Light was delivered from a QB-Quanta_Med-688 nm Light Emitting Diode
Stimulation of Hair Growth in a Mouse Model of Alopecia Areata
A disease closely resembling human alopecia areata has been observed
in aging (over 6-month old) C3H/HeJ mice ( see Sundberg, J. P et
al, Alopecia Areata in Aging C3H/HeJ Mice, Journal of Investigative
Dermatology 102(6): 847 856 [1994[). The C3H/HeJ mouse model has
become recognized as a good model for the study of the etiology
and pathogenesis of alopecia areata and for the evaluation of treatments
for the disease (McElwee, K. J. et al, Comparison of Alopecia areata
in Human and Nonhuman Mammalian Species, Pathobiology 66:90 107
(1998). A study was carried out to determine if topical application
of QLT0074 ointment could influence hair re-growth on C3H/HeJ female
mice exhibiting hair loss. The C3H/HeJ mice were obtained from the
Jackson Laboratories, Bar Harbor, Me. Three animals received QLT0074
ointment, prepared as outlined in Example 2, at 0.2% (w/w) applied
onto balding areas of skin, 1.5.times.1.5 cm in area. All other
areas outside of the treatment site were left untreated.
Following this treatment, all 3 mice received a dose of 50 J/cm.sup.2
688 nm light delivered at a rate of 50 mw/cm.sup.2 in the 1.5 square
area. Mice were monitored for skin photosensitivity reactions on
Days 1 and 3 after light exposure and observed for hair re-growth
for up to 19 days post-treatment. With QLT0074 ointment and red
light treatment, no skin photosensitivity reactions were observed
for mice treated with light. At day 7 post-treatment, an increased
amount of hair was observed in the treatment area of 2 of the 3
All references cited herein, including patents, patent applications,
and publications, are hereby incorporated by reference in their
entireties, whether previously specifically incorporated or not.
Having now fully described this invention, it will be appreciated
by those skilled in the art that the same can be performed within
a wide range of equivalent parameters, concentrations, and conditions
without undue experimentation. This application is intended to cover
any variations, uses, or adaptations of the invention, following
in general the principles of the invention, that include such departures
from the present disclosure as come within known or customary practice
within the art to which the invention pertains and as may be applied
to the essential features hereinbefore set forth.