Method for suppressing the immune response

A method and composition for suppressing the immune response are disclosed which employ an immunosuppressing effective amount of certain substituted quinoline, naphthyridine and pyrido-pyrazine derivatives.

BACKGROUND OF THE INVENTION 
The present invention relates to the use of certain tricyclic quinoline, 
naphthyridine and pyridopyrazine derivatives in suppressing the immune 
response. 
The preparation of the compound 
2'-methylpyrano-5',6':3,4-(2-oxo-1,2-dihydroquinoline) and its N-phenyl 
derivative is described in Bull. Soc. Chim. Fr., pp. 364-9 (1968) (C.A. 
68: 114419c). 
European published Application No. 84105923.1 (European patent publication 
No. 0 127 135) discloses the use of tricyclic quinoline, naphthyridine and 
pyridopyrazine derivatives in treating allergies, inflammation and peptic 
ulcers. 
SUMMARY OF THE INVENTION 
The present invention is drawn to a method for suppressing the immune 
response in a mammal which comprises administering to a mammal in need of 
such treatment an immunosuppressing effective amount of a compound having 
the structural formula I: 
##STR1## 
wherein: 
##STR2## 
B is independently oxygen or sulfur; R.sup.1 -R.sup.8 may be the same or 
different and are hydrogen or alkyl having from 1 to 6 carbon atoms or two 
adjacent R.sup.1 -R.sup.8 substituents may be combined to form an 
additional carbon to carbon bond; 
l and m may be the same or different and are 0 or one; 
the ring labeled, Q, may optionally contain up to two additional double 
bonds; 
n is 0, 1 or 2; 
W and X may be the same or different and are hydrogen, hydroxy, alkyl 
having from 1 to 6 carbon atoms, halogen, nitro, alkoxy having from 1 to 6 
carbon atoms, trifluoromethyl, cyano, cycloalkyl having from 3 to 7 carbon 
atoms, alkenyloxy having from 3 to 6 carbon atoms, alkynyloxy having from 
3 to 6 carbon atoms, S(O).sub.p --R.sup.a {wherein p is 0, 1 or 2 and 
R.sup.a is alkyl having from 1 to 6 carbon atoms}, NHSO.sub.2 R.sup.a 
{wherein R.sup.a is defined herein}, NHSO.sub.2 CF.sub.3, NHCOCF.sub.3, 
SO.sub.2 NH.sub.2, COR.sup.b {wherein R.sup.b is OH, NH.sub.2 or OR.sup.a 
(wherein R.sup.a is defined herein)}, O--D--COR.sup.b {wherein D is 
alkylene having from 1 to 4 carbon atoms and R.sup.b is defined herein}, 
NHCOR.sup.c {wherein R.sup.c is hydrogen, alkyl having from 1 to 6 carbon 
atoms, alkoxy having from 1 to 6 carbon atoms, COR.sup.d (wherein R.sup.d 
is hydroxy or alkoxy having from 1 to 6 carbon atoms) or NHR.sup.e 
(wherein R.sup.e is hydrogen or alkyl having from 1 to 6 carbon atoms)}, 
or phenoxy {wherein the benzene ring may be substituted with any of the 
other substituents W and X}; 
Y and Z may be the same or different and are CH or N; 
V is phenyl, naphthyl, indenyl, indanyl, 2-, 3- or 4-pyridyl, 2-, 3- or 
5-pyrimidinyl, 2- or 3-thienyl, 2- or 3-furyl or 2-, 4- or 5-thiazolyl, 
any of which may be substituted with W and X as defined herein; and 
R.sup.9 and R.sup.10 are independently hydrogen or alkyl having from 1 to 6 
carbon atoms. 
A subgenus of compounds is that wherein B is oxygen. 
Another subgenus of compounds is that wherein B is oxygen and A is A'. 
Still other subgenuses of compounds are those having the structural 
formulas: 
##STR3## 
wherein V, W, X, Z, R.sup.1 -R.sup.8, l and m are as defined herein. 
Individual compounds suitable for use in the method and composition of the 
invention include those having the names: 
3,5-dihydro-5-phenyl-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-phenyl-thieno[3,2-c][1,8]naphthyridin-4[2H]-one; 
6-phenyl-2,3,4,6-tetrahydro-pyrano[3,2-c][1,8]naphthyridin-5-one; 
2-methyl-3,5-dihydro-5-phenyl-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-9-phenyl-furo[2,3-b][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-9-(p-methylphenyl)-furo[2,3-b][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-2-methyl-9-phenyl-furo[2,3-b][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(p-methylphenyl)-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(p-fluorophenyl)-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(m-methoxyphenyl)-furo-[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(m-methylthiophenyl)-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-9-(p-fluorophenyl)-furo[2,3-b][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-9-(m-methoxyphenyl)-furo[2,3-b][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-9-(m-methylthiophenyl)-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(3,4-dichlorophenyl)-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(3,4-dichlorophenyl)-2-methyl-furo[3,2-c][1,8]-naphthyridin-4 
[2H]-one; 
3,5-dihydro-5-(4-chlorophenyl)-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(3-chlorophenyl)-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(3-chlorophenyl)-2-methyl-furo[3,2-c][1,8]naphthyridin-4[2H]- 
one; 
3,5-dihydro-5-(4-fluorophenyl)-2-methyl-furo[3,2-c][1,8]naphthyridin-4[2H]- 
one; 
3,5-dihydro-5-(3-methoxyphenyl)-2-methyl-furo[3,2-c][1,8]-naphthyridin-4[2H 
]-one; 
3,5-dihydro-5-(3,5-dichlorophenyl)-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(3,5-dichlorophenyl)-2-methyl-furo[3,2-c][1,8]-naphthyridin-4 
[2H]-one; 
3,5-dihydro-5-phenyl-2,2-dimethyl-furo[3,2-c][1,8]naphthyridin-4[2H]-one; 
3,5-dihydro-5-(3-methylsulfonylaminophenyl)-2-methylfuro[3,2-c][1,8]-naphth 
yridin-4[2H]-one; 
3,5-dihydro-5-(3-methylsulfonylaminophenyl)-furo[3,2-c][1,8]-naphthyridin-4 
[2H]-one; 
3,9-dihydro-9-(3,4-dichlorophenyl)-furo[2,3-b][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-9-(4-chlorophenyl)-furo[2,3-b][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-9-(3-chlorophenyl)-furo[2,3-b][1,8]naphthyridin-4[2H-one; 
3,9-dihydro-9-(3-chlorophenyl)-2-methyl-furo[2,3-b][1,8]naphthyridin-4[2H]- 
one; 
3,9-dihydro-9-(4-fluorophenyl)-2-methyl-furo[2,3-b][1,8]naphthyridin-4[2H]- 
one; 
3,9-dihydro-9-(3-methoxyphenyl)-2-methyl-furo[2,3-b][1,8]-naphthyridin-4[2H 
]-one; 
3,9-dihydro-9-(3,5-dichlorophenyl)-furo[2,3-b][1,8]naphthyridin-4[2H]-one; 
3,9-dihydro-9-(3,5-dichlorophenyl)-2-methyl-furo[2,3-b][1,8]-naphthyridin-4 
[2H]-one; 
3,9-dihydro-9-(3-methylsulfonylaminophenyl)-2-methyl-furo[2,3-b][1,8]-napht 
hyridin-4[2H]-one; 
6-(4-chlorophenyl)-2,3,4,6-tetrahydro-5H-pyrano[3,2-c][1,8]naphthyridin-5-o 
ne; 
6-(3,4-dichlorophenyl)-2,3,4,6-tetrahydro-5H-pyrano[3,2-c][1,8]naphthyridin 
-5-one; 
6-(4-methoxyphenyl)-2,3,4,6-tetrahydro-5H-pyrano[3,2-c][1,8]naphthyridin-5- 
one; 
6-(4-methylphenyl)-2,3,4,6-tetrahydro-5H-pyrano[3,2-c][1,8]naphthyridin-5-o 
ne; 
10-(3,4-dichlorophenyl)-2,3,4,10-tetrahydro-5H-pyrano[2,3-b][1,8]naphthyrid 
in-5-one; 
10-(4-methoxyphenyl)-2,3,4,10-tetrahydro-5H-pyrano[2,3-b][1,8]naphthyridin- 
5-one; 
10-(4-chlorophenyl)-2,3,4,10-tetrahydro-5H-pyrano(2,3-b][1,8]naphthyridin-5 
-one; 
10-(4-methylphenyl)-2,3,4,10-tetrahydro-5H-pyrano(2,3-b][1,8]naphthyridin-5 
-one; 
10-phenyl-2,3,4,10-tetrahydro-5H-pyrano-[2,3-b][1,8]-naphthyridin-5-one; 
7-phenyl-3,4,5,7-tetrahydro-oxepino[3,2-c][1,8]-naphthyridin-6[2H]-one; 
7-(4-chlorophenyl)-3,4,5,7-tetrahydro-oxepino[3,2-c][1,8]-naphthyridin-6[2H 
]-one; 
7-(3-chlorophenyl)-3,4,5,7-tetrahydro-oxepino[3,2-c][1,8]-naphthyridin-6[2H 
]-one; 
7-(3-methoxyphenyl)-3,4,5,7-tetrahydro-oxepino[3,2-c][1,8]-naphthyridin-6[2 
H]-one; and 
7-(3-hydroxyphenyl)-3,4,5,7-tetrahydro-oxepino[3,2-c][1,8]-naphthyridin-6[2 
H]-one. 
As disclosed in European published application No. 84105923.1 (European 
patent publication No. 0 127 135), these compounds possess anti-allergy 
and anti-inflammatory activities. It has now unexpectedly been found that 
these compounds possess immunosuppressive activity. 
DESCRIPTION OF THE INVENTION 
When utilized herein and in the appended claims the below listed terms, 
unless specified otherwise, are defined as follows: 
halogen--fluorine, chlorine, bromine and iodine; 
alkyl and alkoxy--comprised of straight and branched carbon chains 
containing from 1 to 6 carbon atoms; 
alkenyloxy--comprised of straight and branched carbon chains containing 
from 3 to 8 carbon atoms and comprising a carbon to carbon double bond; 
and 
alkynyloxy--comprised of straight and branched carbon chains containing 
from 3 to 8 carbon atoms and comprising a carbon to carbon triple bond. 
The compounds of the invention may possibly contain two different "B" 
substituents. It is intended that both may simultaneously be oxygen or 
sulfur, or that either may be oxygen or sulfur. 
In certain compounds of the invention, the ring labeled Q, may contain up 
to two additional double bonds which double bonds are formed by the 
combination of two adjacent substituents, R.sup.1 -R.sup.8. Thus, for 
example, when Q is a 7 membered ring (l and m are both equal to 1) it may 
contain 3 double bonds. When multiple double bonds are present, they will 
be non-cumulated double bonds. 
The compounds of the invention are comprised of a --(CR.sup.9 
R.sup.10).sub.n -- substituent wherein the R.sup.9 and R.sup.10 groups may 
vary independently. Thus, for example, when n equals 2, the following 
patterns of substitution (wherein hydrogen and CH.sub.3 are used to 
represent any substituent, R.sup.9 or R.sup.10,) are contemplated: 
--C(CH.sub.3).sub.2 CH.sub.2 --, --CH.sub.2 C(CH.sub.3).sub.2 --, 
--CH.sub.2 CH(CH.sub.3)--, --CH(CH.sub.3)CH.sub.2 --, 
--(C(CH.sub.3)H).sub.2 -- and the like. In addition when n equals 2, 
substituents such as --C(CH.sub.3).sub.2 CH(C.sub.2 H.sub.5)--, 
--CH(CH.sub.3)CH(C.sub.2 H.sub.5)--, --CH(i--C.sub.3 H.sub.7)CH(C.sub.2 
H.sub.5)-- are also contemplated. 
Certain compounds of the invention may exist in isomeric forms. The 
invention contemplates all such isomers both in pure form and in 
admixture, including racemic mixtures. 
The compounds of formula I can exist in unsolvated as well as solvated 
forms, including hydrated forms. In general, the solvated forms, with 
pharmaceutically acceptable solvents such as water, ethanol and the like 
are equivalent to the unsolvated forms for purposes of the invention. 
The compounds which are utilized in the method and composition of this 
invention are disclosed in U.S. application No. 499,584 filed May 31, 
1983, in U.S. application No. 597,887 filed Apr. 9, 1984 and in European 
published patent application No. 84195923.1 (publication number: 0 127 
135). These compounds may be prepared by methods described in those U.S. 
applications and European published application, the disclosures of which 
are incorporated herein by reference for that purpose. 
The compounds of formula I are useful in the treatment of autoimmune and 
other immunological diseases including graft rejection in which T cell 
proliferation is a contributing factor to the pathogenesis of disease. The 
effectiveness of these compounds as immunosuppressing agents may be 
demonstrated by the following tests which involve the inhibition of T cell 
functions using these compounds. 
GRAFT VS. HOST REACTION (GVHR) 
To induce a GVHR, C57 B1/6XA/J(B6AF1) male mice were injected intravenously 
with parental (C57B1/6J) spleen and lymph node cells. The compound 
10-(4-chlorophenyl)-2,3,4,10-tetrahydro-5H-pyrano[2,3-b][1,8]naphthyridin- 
5-one (Compound A) was then administered orally for 10 days beginning on 
the day prior to the cell transfer. On the day following the last 
treatment, the animals were sacrificed, and their spleens were excised and 
weighed. The enlargement of the spleen of the host is a result of a GVHR. 
To some extent it is the host's own cells which infiltrate and enlarge the 
spleen although they do this because of the presence of graft cells 
reacting against the host. The amount of spleen enlargement, splenomegaly, 
is taken as a measure of the severity of the GVHR. 
In carrying out the GVHR the animal in the experimental group is injected 
with parental cells, cells of the same species but of different genotype, 
which cause a weight increase of the spleen. The animal in the control 
group is injected with syngeneic cells, genetically identical cells which 
do not cause a weight increase of the spleen. The effectiveness of 
Compound A administered to the mice in the experimental group is measured 
by comparing the spleen weight of the untreated and treated GVH animal 
with that of the syngeneic control. Compound A reduced spleen weight by 8% 
as compared to the untreated animals at a dose of 100 mg/kg. 
ANTI-SHEEP RED BLOOD CELL RESPONSE 
The immunosuppressive activity of the compounds of formula I may also be 
shown by the inhibition of the secretion of IgM by B. cells in mice 
immunized with sheep erythrocytes. In particular, BDF.sub.1 are mice are 
immunized intravenously with 1.times.10.sup.8 sheep erythrocytes on day 
zero. Treatment with the test drug (oral administration) is initiated the 
day prior to the immunization and is continued through day three. On day 
four the number of IgM secreting cells in the spleens of the treated mice 
are assessed by the Jerne Plaque technique, with the results expressed as 
a percent inhibition in comparison to untreated controls. Compound A at 
100 mg/kg per day and 
9-(3-chlorophenyl)-3,9-dihydro-2-methyl-furo[2,3-b][1,8]naphthyridin-4[2H] 
-one (Compound B) at 100 mg/kg per day provided about 10% and about 27-36% 
inhibition, respectively, in this test procedure. 
As noted, European patent publication No. 0 127 135 discloses that the 
subject compounds possess anti-allergy and anti-inflammatory activities. 
For example, Compound A at a concentration of about 10 .mu.M provided 
about 57% inhibition of SRS-A release in the procedure described in 
Kreutner et al., European Journal of Pharmacology, Vol. 111, 1985, pp 1-8. 
Compound A has an ED.sub.30 value of about 6 mg/kg p.o. in tests measuring 
the reverse passive Arthus reaction in the pleural cavity of rats (as 
described by Myers et al., Inflammation, Vol. 9, No. 1, 1985, pp. 91-98). 
These results for Compound A indicate that an immunosuppressive effective 
dose for the compounds of formula I is several times their 
anti-inflammatory and anti-allergy effective doses. 
The usual dosage range for the compounds of formula I in a 70 kg mammal is 
a dose of about 0.1 to 250 mg/kg, preferably 0.1 to 150 mg/kg per day. The 
compounds may be administered by conventional routes, e.g., orally, 
subcutaneously, intramuscularly, etc. Orally the compound may be 
administered in 3 or 4 divided doses per day. Of course, the dose will be 
regulated according to the potency of compound employed, the immunological 
disease being treated, and the judgment of the attending clinician 
depending on factors such as the degree and the severity of the disease 
state and age and general condition of the patient being treated. 
To treat immunological diseases, the active compounds of formula I can be 
administered in unit dosage forms such as tablets, capsules, pills, 
powders, granules, sterile parenteral solutions or suspensions, 
suppositories, transdermal compositions and the like. Such dosage forms 
are prepared according to standard techniques well known in the art. 
For preparing pharmaceutical compositions from the compounds described by 
this invention, inert, pharmaceutically acceptable carriers can be either 
solid or liquid. Solid form preparations include powders, tablets, 
dispersible granules, capsules, cachets and suppositories. A solid carrier 
can be one or more substances which may also act as diluents, flavoring 
agents, solubilizers, lubricants, suspending agents, binders or tablet 
disintegrating agents; it can also be an encapsulating material. In 
powders, the carrier is a finely divided solid which is in admixture with 
the finely divided active compound. In the tablet the active compound is 
mixed with carrier having the necessary binding properties in suitable 
proportions and compacted in the shape and size desired. The powders and 
tablets preferably contain from 5 to about 70 percent of the active 
ingredient. Suitable solid carriers are magnesium carbonate, magnesium 
strearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, 
tragacanth, methylcellulose, sodium carboxymethylcellulose, a low melting 
wax, cocoa butter and the like. The term "preparation" is intended to 
include the formulation of the active compound with encapsulating material 
as carrier providing a capsule in which the active component (with or 
without other carriers) is surrounded by carrier, which is thus in 
association with it. Similarly, cachets are included. Tablets, powders, 
cachets and capsules can be used as solid dosage forms suitable for oral 
administration. 
For preparing suppositories, a low melting wax such as a mixture of fatty 
acid glycerides or cocoa butter is first melted, and the active ingredient 
is dispersed homogeneously therein as by stirring. The molten homogeneous 
mixture is then poured into convenient sized molds, allowed to cool and 
thereby solidify. 
Liquid form preparations include solutions, suspensions and emulsions. As 
an example may be mentioned water or water-propylene glycol solutions for 
parenteral injection. Liquid preparations can also be formulated in 
solution or suspension in aqueous polyethylene glycol solution. Aqueous 
solutions suitable for oral use can be prepared by adding the active 
component in water and adding suitable colorants, flavors, stabilizing, 
sweetening, solubilizing and thickening agents as desired. Aqueous 
suspensions suitable for oral use can be made by dispersing the finely 
divided active component in water with viscous material, i.e., natural or 
synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose and 
other well-known suspending agents. 
Also included are solid form preparations which are intended to be 
converted, shortly before use, to liquid form preparations for either oral 
or parenteral administration. Such liquid forms include solutions, 
suspensions and emulsions. These particular solid form preparations are 
most conveniently provided in unit dose form and as such are used to 
provide a single liquid dosage unit. Alternately, sufficient solid may be 
provided so that after conversion to liquid form, multiple individual 
liquid doses may be obtained by measuring predetermined volumes of the 
liquid form preparation as with a syringe, teaspoon or other volumetric 
container. When multiple liquid doses are so prepared, it is preferred to 
maintain the unused portion of said liquid doses at low temperature (i.e., 
under refrigeration) in order to retard possible decomposition. The solid 
form preparations intended to be converted to liquid form may contain, in 
additions to the active material, flavorants, colorants, stabilizers, 
buffers, artificial and natural sweeteners, dispersants, thickeners, 
solubilizing agents and the like. The solvent utilized for preparing the 
liquid form preparation may be water, isotonic water, ethanol, glycerine, 
propylene glycol and the like as well as mixtures thereof. Naturally, the 
solvent utilized will be chosen with regard to the route of 
administration, for example, liquid preparations containing large amounts 
of ethanol are not suitable for parenteral use. 
The composition of the invention may also be deliverable transdermally. The 
transdermal compositions can take the form of creams, lotions and/or 
emulsions and can be included in a transdermal patch of the matrix or 
reservoir type as are conventional in the art for this purpose. 
Preferably, the pharmaceutical preparation is in unit dosage form. In such 
form, the preparation is subdivided into unit doses containing appropriate 
quantities of the active component. The unit dosage form can be a packaged 
preparation, the package containing discrete quantities of preparation, 
for example, packeted tablets, capsules and powders in vials or ampoules. 
The unit dosage form can also be appropriate number of any of these in 
packaged form. The compositions can, if desired, also contain other 
therapeutic agents. 
The dosages may be varied depending upon the requirements of the patient, 
and severity of the condition being treated and the particular compound 
being employed. Determination of the proper dosage for a particular 
situation is within the skill of the art. Generally, treatment is 
initiated with smaller dosages which are less than the optimum dose of the 
compound. Thereafter, the dosage is increased by small increments until 
the optimum effect under the circumstances is reached. For convenience, 
the total daily dosage may be divided and administered in portions during 
the day if desired. 
The following examples are intended to illustrate, but not to limit, the 
present invention. The term "Compound A" refers to 
10-(4-chlorophenyl)-2,3,4,10-tetrahydro-5H-pyrano[2,3-b][1,8]-naphthyridin 
-5-one. It is contemplated, however, that this compound may be replaced by 
equally effective quantities of other compounds of formula I as defined 
above.