METHOD OF TREATING VIRAL DISEASES

Abstract: A therapeutic process for treating disease in mammals caused by DNA viruses or retroviruses, in which the infected mammal is treated with a polyhydroxy benzoic, mandelic or phenylacetic acid derivative, such as N,3,4-trihydroxybenzamide.

Description: METHOD OF TREATING VIRAL DISEASES BACKGROUND OF THE INVENTION This invention relates to a method of suppressing the growth or reproduction of DNA viruses and of retroviruses in mammals infected with one or more of said viruses. The term "DNA virus" is defined as being a virus with a DNA genome and the term "retrovirus" is defined as being a RNA virus having a reverse transcriptase (RNA-dependent DNA polymerase) within the virion, according to the TEXTBOOK OF HUMAN VIROLOGY, 2nd ed. R. B. Belshe Ed., (Mosby, St. Louis 1991). Among the DNA viruses whose growth is suppressed in vivo by the therapeutic processes of this invention are included the Paroviruses which can infect both rodents (Kilham's virus, Aleutian mink disease), feline, dogs and humans (Parovirus strain B19 and RA- 1 virus), the Papovaviruses which include the Papilloma viruses which can cause human papilloma (warts) and infect rabbits (Shope papillomavirus ) , and the Polyomaviruses which infect primates (vacuolating virus of Rhesus monkeys and JC and BK viruses of man). JC virus is associated with progressive multifocal leukoencephalopathy (PML). Other DNA viruses which can have their in vivo growth in mammals suppressed by the processes of this invention include the Adenoviruses which cause acute respiratory diseases, febrile catarrhs, pharyngitis and conjunctivitis of man, the Herpes viruses which causes both latent and persistent infection in man including Epstein-Barr herpesvirus (Lymphocryptovirus) associated with human Burkitt's lymphoma, nasopharyngeal carcinoma and causes infectious mononucleosis in man; Herpes simplex which causes both fever 1 SUBSTITUTE SHEET blisters and genital herpes among other human diseases as well as chicken pox. Simian B virus, often fatal to man; Herpes zoster ( aricellovirus ) which causes shingles in man; Betaherpes viruses which are associated with cytomegalic inclusion disease and infection of T and B cell leukocytes; the hepadnaviruses which, upon infection in man are associated with hepatitis, hepatocellular carcinoma and immunecomplex-mediated extrahepatic injury including both hepatitis B and C, and, in domestic animals, swine pseudorabies as well as other viruses which cause disease in both cattle and horses. Retroviral diseases which are treatable by the therapeutic processes of this invention include the RNA tumor viruses (oncoviruses) and the slow viruses (lentiviruses). Specific oncovirus diseases include, in man, T-cell leukemia, human T-cell lymphotropic viruses (HTLV-I and II) as well as the murine viruses including Friend leukemia virus and Rauscher and Moloney murine leukemia viruses. In addition, there are included leuke ic diseases of cats, birds, hamsters and primates other than man. Among the lentivirus diseases , HIV which causes AIDS in man is the most prominent. One of the major problems in finding treatment methods for persons infected with one or more DNA or retroviruses is the occurrence of an asymptomatic viremia lasting from several weeks to several years or, in the case of Herpes simplex infections, of recurrent episodes after periods of dormancy while the human subject still harbors the virus. Thus, the ideal method of treating a retroviral disease would be to use a drug that can destroy all cells harboring latent virus, rather 2 than simply finding a drug which is only useful after an initial exposure and acts by preventing implanting of the virus or provirus into host chromosomal cells or by inhibiting other early steps in the viral replication cycle. Another therapeutic approach would be to find a drug capable of stimulating the immune system of the host, AZT, the first drug currently approved for the treatment of AIDS, is targeted against reverse transcriptase, an enzyme with a critical function in the early part of the retroviral life cycle. Unfortunately, AZT can cause anemia after prolonged administration. A second major problem which has hindered the search for effective anti-AIDS drugs has been the lack of an animal model. Ruprecht et al CANCER RESEARCH (SUPPL.) J50 5618a Sept. 1, 1990 describe and evaluate the various models then available for evaluating antiLetroviral therapy. Johnson et al ibid 5682 have described a useful murine model which utilizes the retrovirus, Friend leukemia virus, in what is described as a Friend Virus-induced ErythroLeukemia Model. This system for the first time enables investigators to evaluate various anti- retroviral treatment methods and drugs useful in such methods as candidates for the therapy of AIDS and other retroviral diseases. SUBSTITUTE SHEET SUMMARY OF THE INVENTION This invention provides a therapeutic process for the treatment of diseases caused by DNA viruses or retroviruses in mammals which comprises administering to a mammal suffering from one or more of said viral diseases and in need of treatment, an amount of a drug represented by the following formula sufficient to suppress the growth of said virus in said mammal wherein n is 2-5 , m is 0 or 1, R is NH„ , oc τ _ 3 alkyl or 0- phenyl, R' is 0, NH or NOH and R" is H or OH. Also included are the pharmaceuti cally-acceptable salts of compounds according to the above formula where chemically feasible. Also included within the scope of this invention are the phenolic ace yl derivatives of compounds according to the above formula. Such acetyl derivatives act as "pro-drugs" in that they are converted by the mammalian body to the corresponding compound having entirely unesterified phenolic hydroxyls , which are the therapeutically active drugs . Illustrative of the polyhydroxy-substituted phenyl ring in the above formula are included 2 , 3-dihydroxyphenyl , 3 , 4- dihydroxyphenyl , 2 , 5-dihydroxyphenyl , 2 , 6-dihydroxyphenyl, 2 , 3 , 4-trihydroxyphenyl , 2 , 3 , 5-tr ihydroxyphenyl , 3 , 4 , 5- trihydroxyphenyl , 2 , 4 , 5-tr ihydroxyphenyl, pentahydroxyphenyl , 2, 3 ,4,5-tetrahydroxyphenyl and the like groups . In the above formula , when m is 1 and R" is H, a SUBSTITUTE SHEET phenylacetic acid derivative is denominated. When m is 1 and R" is OH, a mandelic acid derivative is represented. When m is 0, R is NHOH and R' is 0, an N-hydroxybenzamide (formerly, a benzohydroxamic acid) is represented; when R is NH„ and R 1 is NH, a benzimidamide (formerly a benzamidine) is represented; when R is NHOH and R' is NH, an N-hydroxy benzimidamide (formerly a benzamidoxime) is shown; when R is NHOH and R 1 is NOH, an , N ' -dihydroxy benzimidamide (formerly, an hydroxyamidoxime) is represented; and when R is 0-alkyl or 0- phenyl and R 1 is NH, the resulting compounds are benzimidates (rather than benzamidates as previously). In the above formula, when R is OC, -. alkyl, the alkyl groups represented include methyl, ethyl, isopropyl and n-propyl. Compounds represented by the above formula are fully illustrated in United States Patents 4,253,322, 4,623,659, 2,848,430 and 3,629,443. Methods for their preparation are also fully disclosed in those patents as well as in the many references cited therein. In particular, the compounds listed in Cols. 2 and 3 of United States Patent 4,623,659 illustrate the scope of the compounds represented by the above formula (always remembering that the approved nomenclature for these structures has changed since 1983 when the application which resulted in that patent was filed) and the disclosure of United States Patent 4,623,659 is incorporated herein, and made a part of, by reference. It will be apparent to those skilled in the art that the therapeutic processes of this invention are directed to the treatment of diseases caused by DNA viruses and by one class of 5 SUBSTITUTE SHEET RNA viruses, the retroviruses, other viruses containing an RNA genome among those listed in THE TEXTBOOK OF HUMAN VIROLOGY (loc. cit. ) may be successfully treated and their replication prevented in vivo by administration of a drug according to the above formula. It will also be apparent to those skilled in the art that other phenolic blocking groups, such as the acetyl group specified above, may be employed, including esters of other lower alkanolic acids, as well as phenacyl esters and the like, to yield potential pro-drugs, only provided that the ester group on a phenolic hydroxyl is removable by the mammalian host to whom it was administered. As previously stated, the therapeutic processes disclosed by this invention are useful in suppressing the growth or reproduction of DNA viruses and retroviruses in mammals, including primates such as new-world monkeys, and the great apes including man, in rodents, ungulates (both cattle and sheep), in horses, swine, mink, etc. An illustration of such therapeutic process, utilizing the retrovirus Friend leukemia virus in mice, is illustrated in the next section. 6 SUBSTITUTESHEET BIOLOGICAL TESTING To test the ability of the compounds of the above formula to suppress the growth of retroviruses in vivo, the following protocol was used: six week old female mice (B6D2/F1 hybrids) were infected with Friend leukemia virus (FLV) on day 0. The FLV employed is classified as a murine leukosis sarcoma complex retrovirus that causes red blood cell tumors in the spleen resulting in splenomegaly and was obtained from the American Type Culture Collection, ATCC No. VR-245. The drug was administered parenterally (via the intraperitoneal route) daily for 12 days starting on day 1. The mice were sacrificed on day 14 for collection of spleen, liver and blood. In an initial experiment, the treatment groups included the following: Didox (N, 3 , 4-trihydroxybenzamide) at 450 g/kg, Amidox (N,3,4- trihydroxybenzimidamide as the HC1 salt) at 225 mg/kg, FLV- infected saline control, saline control. There were four mice per treatment group. Table 1 below gives the spleen and liver weights for the four groups. TABLE 1 Relative Spleen and Liver Weights, Didox and Amidox TREATMENT GROUP SPLEEN WT.** LIVER WT.** Mean - S.E. Saline Control 0.33±0.1* 4.76-.11 FLV-Saline 6.20^1.73 5.62-.40 FLV-Didox 0.47±.06* 4.88-.26 FLV-A idox 1. A8- . A8 4.76±.ll * = statistically significant at alpha = 0.05 ** = % of body weight Blood cell count data on the above groups plus a Didox and an Amidox uninfected group (at the same dose rate as with the infected groups) as a further control gave the results given in Table 2 below. TABLE 2 Blood Count and Percent Reticulocytes for Table 1 Groups TREATMENT GROUP WBC RBC HGB PLT % RET FLV-Saline + Saline FLV-Didox 450 FLV-Amidox 225 +_ Didox 450 Amidox 225 * and ** correspond to alpha levels of .05 and .01 respecti ely. As can be seen from the data presented in Tables 1-2, Didox reduced the splenomegaly associated with murine FLV infection to control levels, indicating an almost total suppression of the retrovirus. Liver weights were not significantly increased over control weights whereas the FLV- infec ed mice showed a large increase in liver weight. Both these results demonstrate the effectiveness of Didox in 8 suppressing FLV since FLV infection in mice invariably gives an increase in both spleen and liver weights. Amidox gave a qualitatively similar effect. In the blood, the Didox-treated FLV-infected mice showed an essentially normal WBC (compared to the tremendous increase found in FLV infected mice). RBC and hemoglobin values were decreased compared to FLV-saline controls. Amidox gave similar, but not as pronounced, results. Both Didox and Amidox in the uninfected controls decreased platelet counts, as well as in the infected and the drug-alone control groups. All of the treatment and control groups with Didox and Amidox gave essentially normal reticulocyte levels whereas the FLV-saline controls showed a marked increase in the percentage of reticulocytes. It is apparent from the above data that Didox, and to a lesser extent, Amidox, at the dose levels tested, are able to suppress growth of the retrovirus, FLV, in FLV-infected mice. In a further exploration of the ability of Didox to suppress the growth of the retrovirus, FLV, Didox was administered as before to groups of FLV-infected hybrid mice at dose levels varying from 28-450 mg/kg using the previous protocol. In addition, one group of mice treated at the 450 mg/kg level were sacrificed on day 28, rather than day 14 (although treatment was terminated on day 12 as before) as with the other groups of infected mice, in order to determine whether the positive effects seen -t 14 days would persist. The results of that and the other experiments are given in Table 3 below. 9 SUBSTITUTESHEET TABLE 3 Relative Spleen and Liver Weights for Didox Treated Mice TREATMENT GROUP SPLEEN WT. LIVER WT. Mean — S.E. FLV-Saline 3.84-.180 5.77-0.53 FLV-450 Didox 0.35 ± 0.03 5.71-0.27 FLV-450 Didox (28 day) 1.50-0.52 5.76*0.27 FLV-225 Didox 1.89-0.69 5.67-0.19 FLV-112.5 Didox 4.39*1.56 6.12-0.51 FLV-56.25 Didox 5.40-1.81 5.95-0.57 FLV-28 Didox 4.94-1.59 5.51-0.36 Saline 0.35*0.01 4.75-0.06 All numbers in col. 1 refer to mg/kg of Didox for 12 days. Blood studies, as in Table 2 , were carried out on the mouse groups in Table 3. Although not statistically significant, WBC, platelet and % reticulocytes were generally lower in the FLV-infected, Didox treated mice. The higher dose levels (450 and 225 mg/kg) gave the most drastic reductions. It is also apparent that, in FLV-infected mice, only the higher dose levels of Didox were effective to suppress the growth of the virus in vivo. In addition, the 450 mg/kg dose level of Didox demonstrated some long-lasting positive effects in FLV-infected mice long after the therapy had been terminated. Although two of the compounds represented by the above formula, Didox and Amidox, were administered in saline to retrovirus infected mice by the intraperitoneal route, other parenteral routes (intravenous, intramuscular, intradermal or 10 SUBSTITUTESHEET intrathecal) could also be used and the pounds formulated for such parenteral routes in accordance v, _h the skill of the art, preferably in isotonic solution. The same considerations apply to oral medications containing Didox or Amidox, i.e., tablets, filled gelatin capsules, or liquid formulations. As will be apparent also " to those skilled in the art, the effective dose levels will vary according to the mode of administration. For examp-i, oral dose levels would be higher, and intravenous or intramuscular levels lower in general than intraperitoneal dose levels. Drug carriers may also be employed and the viral F ppressive agents of this invention can be combined in a cc ύnation dosage form with, or be administered at the same time as, other viral suppressive agents, immune stimulators and the like. Phenol-acetylated compounds ac ording to the above formula, although called "pro- drugs" herein, can also be considered as a special type of drug carrier. 11 SUBSTITUTESHEET

Claims: We claim: 1. A therapeutic procedure for treating mammalian diseases caused by DNA viruses or retroviruses which comprises administering to a DNA virus or retrovirus infected mammal in need of treatment an amount of a compound of the following formula s uf f i c ient to at least partially suppress the growth or reproduction of said virus in said mammal wherein n is 2-5, m is 0 or 1, R is NOH, H-, C- ι _ o alkyl or 0-phenyl f R" is 0, NH, or NOH, R" is H or OH and pharmaceutically-acceptable acid-addition salts and acetylated phenol derivatives thereof. 2. A procedure according to Claim 1 in which the anti-viral drug is N,3,4-trihydroxybenzamide. 3. A procedure according to Claim 1 in which the anti-viral drug is N,3,4,5-tetrahydroxybenzimidamide. 4. A procedure according to Claim 1 in which the infection being treated is caused by a retrovirus. 5. A process according to Claim 1 in which the infection being treated is caused by a DNA virus. 6. A procedure according to Claim 4 in which the retrovirus is HIV-1. 7. A procedure according to Claim 5 in which the DNA virus is a herpes virus. 8. A procedure according to Claim 7 in which the herpes virus is Herpes simplex. 9. A procedure according to Claim 5 in which the DNA virus infection being treated is caused by a hepadnavirus. 10. A procedure according to Claim 9 in which the disease caused by virus is Hepatitis B or C. 11. A procedure according to Claim 1 in which the viral disease is caused by Friend leukemia virus and the infected mammal is a mouse. 12. A procedure according to Claim 1 in which the viral disease being treated is caused by HIV-1 and the infected mammal is man. 13. A procedure according to Claim 1 in which the viral disease being treated is caused by HIV-2 and the infected mammal is man. 14. A procedure according to Claim 4 in which the retrovirus is HIV-2. 13 SUBSTITUTE

Inventors: ELFORD HOWARD L, VAN T RIET BARTHOLOMEUS, ELFORD, HOWARD, L., VAN'T RIET, BARTHOLOMEUS
Applicants: ELFORD HOWARD L, RIET BARTHOLOMEUS VAN T, ELFORD, HOWARD, L., VAN'T RIET, BARTHOLOMEUS
Application year: 1992
Main classification: A61K31
IPC codes: A61K31, C12N5