IE913341A1

IE913341A1 - Pharmaceutical compositions and use thereof

Info

Publication number: IE913341A1
Application number: IE334191A
Authority: IE
Original assignee: Ml Lab Plc
Priority date: 1990-09-25
Filing date: 1991-09-24
Publication date: 1992-02-25
Also published as: JPH06502846A; PT99058B; CA2092093A1; EP0550529A1; WO1992004909A1; NZ239909A; AU8612791A; ZA917596B; PT99058A; GB9020872D0; AU653962B2

Abstract

The invention provides an agent against HIV and related viruses, in dosage unit form, comprising CD4 or a CD4-like material and a polyanionic anti-HIV agent, the content of CD4 or CD4-like material in the agent being less than the anti-virally effective dose of the CD4 or CD4-like material alone. It has been found that when the CD4 or CD4-like material is used together with a polyanionic anti-HIV agent, the combination is more effective against HIV infection than would be the case if the anti-viral effect was simply additive.

Description

PHARMACEUTICAL COMPOSITIONS AND OSE THEREOF PvcoGk νε Case- Ά This invention relates to pharmaceutically active compositions and to their use as agents against human immunodeficiency virus and related viruses.

The HIV infection cycle includes a number of steps, each of these steps being a possible target for the use of chemotherapy to hinder the infection. The first step in the infection cycle is the attachment of the HIV virus to the host cell. The main receptor for the virus is believed to be the cell surface glycoprotein, designated CD4, which is present in some Tlymphocytes and in some macrophages. Much attention has therefore been given to identifying agents which are capable of blocking attachment of the virus to CD4.

It is believed that the HIV virus attaches itself to CD4 by means of interaction between CD4 and the surface glycoprotein, gpl20, of the virus. It has been found that soluble recombinant CD4 (srCD4), made by genetic engineering, can block attachment of HIV virus to cellular CD4, thereby inhibiting HIV infection in vitro. Therefore, it has appeared that HIV infection might be preventable by administration of srCD4. Other CD4-like materials, capable of binding to gpl20, such as CD4-IgFc immunoadhesins, CD4 V1-V2 domains, and CD4-derived peptides, have also been proposed as anti-HIV agents. However, the performance of CD4 and CD4-like materials in preventing the HIV virus from binding to cells has until now been disappointing, a much higher concentration of the agent being necessary than had been hoped.

Other anti-HIV agents which block attachment of the virus to cells are a number of polyanionic compounds which include Evans Blue, aurintricarboxylic acid (ATA), suramin, and certain sulphated polysaccharides. It might have been thought that if CD4 and such polyanionic anti-HIV agents were used simultaneously, the total anti-HIV activity would at best be the sum of their separate activities.

However, we have now found that when CD4 (which is used here and below, except where otherwise indicated, to include both CD4 and CD4-like materials) and a polyanionic anti-HIV agent, such as sulphated polysaccharide, are used together, they are much more effective against HIV infection than would be the case if the anti-viral effect was simply additive.

Accordingly, the invention provides an agent against HIV and related viruses, in dosage unit form, comprising CD4 or a CD4like material and a polyanionic anti-HIV agent the content of CD4 and CD4-like material in the agent being less than the antivirally effective dose of the CD4 or CD4-like material alone.

The agent according to the invention may contain substantially less CD4 than the anti-virally effective dosage of CD4 alone, i.e. in the absence of a polyanionic anti-HIV agent. The reduction in the amount of CD4 required to achieve the same antiviral effect as for CD4 alone may be such that less than onetenth (or, in favourable cases, less than one-hundredth) of the amount of CD4 is needed. Accordingly, the invention offers the possibility of using CD4 as a component of an anti-HIV agent in a reduced and therefore safer and more economical amount than has previously been feasible.

The agent according to the invention may also contain less than the normally effective dose of the polyanionic compound. This is advantageous because many of the known polyanionic anti-HIV agents are significantly toxic. For example, sulphated polysaccharides have anti-coagulant activity. When the polyanionic anti-HIV agent is a sulphated polysaccharide, it may be present in the compositions of the invention in an amount which is less than that which would be required in an anti-HIV agent containing only the sulphated polysaccharide.

Consequently, the compositions of the invention which contain sulphated polysaccharides may have a lower level of anticoagulant activity attributable to the sulphated polysaccharide content than those previously known.

The polyanionic anti-HIV agents used in the present invention are preferably sulphated polysaccharides. They include, for example, dextran sulphate, pentosan polysulphate, fucoidan, and dextrin sulphate. Other sulphated polysaccharides having anti-HIV activity (see, for example, EP specifications No's 240,098 and 293,826) may also be used. Preferably, the sulphated polysaccharide contains at least one sulphate group per saccharide unit.

In therapeutic use, the anti-HIV agent of the invention may be administered enterally (including orally) or parenterally (including intravenously). However, administration via the peritoneum may be more effective in that it results in entry of at least some of the anti-HIV agent directly into the lymphatic system, within which system viral replication may be extensive.

The invention also provides the use of the agent described above against HIV-1 and relates viruses, the agent preferably being administered peritoneally.

Further, the invention provides a pharmaceutical composition containing the anti-HIV agent of the invention together with an inert carrier or diluent and the agent of the invention for use in the manufacture of a pharmaceutical composition against HIV-1 and related viruses.

The invention additionally provides a method of treatment of a human or animal subject carrying the HIV-1 virus or a related virus, comprising administering to the subject a pharmaceutically effective amount of the agent of the invention.

The CD4 or CD4-like material and the polyanionic anti-HIV agent may be administered to a subject one after the other, in any order although preferably with the CD4 or CD4-like material being administered before the polyanionic agent, when used against HIV-1 or a related virus.

The invention thus provides CD4 or a CD4-like material, of an amount less than its usual anti-virally effective dose, and a polyanionic anti-HIV agent, for use in a method of treatment of a human or animal subject carrying the HIV-1 virus or a related virus in which the CD4 or CD4-like material are administered to the subject one after the other.

The following example illustrates the synergistic action of dextrin sulphate with soluble recombinant CD4 (srCD4). The dextrin sulphate was produced by sulphation of a dextrin of weight average molecular weight of about 20,000 daltons, using a sulphur trioxide/trimethylamine complex, the degree of substitution being approximately one sulphate group per glucose unit. The srCD4 was produced in a baculo virus system and was purchased from American Biotechnology Inc.

Example 1 In a duplicated experiment, 2-fold dilutions of soluble recombinant CD4, to yield final concentrations of 6 ug/ml down to 0.02 ug/ml, were incubated with 2.5 x 103 TCID (tissue culture infection dose) of HIV-1 virus supernatant (HTLV-IIIb strain, Gallo, 1984) at 37°C for 1 hour. 2-fold dilutions of dextrin sulphate to yield final concentrations from 10 ug/ml down to 0.625 ug/ml were then added to the T-cell line, M8166, at a density of 2.5 x 10^/ml and incubated at 37°C for 1 hour. The srCD4/HIV-l was then added to the dextrin sulphate pre-treated M8I66 cells, and the plates read at 48 - 72 hours for the presence of syncytia, shown in the table below by +.

In the absence of dextrin sulphate, srCD4 inhibited HIV-1 infection of M8166 cells at 6 ug/ml (final concentration). In the absence of srCD4, dextrin sulphate inhibited HIV-1 infection of M8166 cells at 5-10 ug/ml. When both drugs were present, 2.5 - 5.0 ug/ml of dextrin sulphate inhibited HIV-1 infection in the presence of srCD4 at a concentration of 0.05 - 0.09 ug/ml. This represents a 10^ reduction in the quantity of srCD4 required to prevent HIV-1 infection, and shows that the effect of the two drugs together is synergistic rather than simply additive.

FIRST EXPERIMENT Dextrin srCD4 (ug/ml) Sulphate (ug/ml) _ 6 3 1.5 0.75 0.375 0.18 0.09 0.05 0.02 0 □ 2.5 - - - - - - - - + + 1.25 - - - - + + + + + + 0.625 - - + + + + + + Μ- + 0 + + + + + + + Η- + SECOND EXPERIMENT Dextrin srCD4 (ug/ml) Sulphate (ug/ml) _______ 6 3 1.5 0.75 0.375 0.18 0.09 0.05 0.02 0 10 - - - - - - - - - - 5 - - - - - - - + + + 4 - - - - + + + + + + 3 - - + + + + + + + + 2 - + + + + + + + + + 1 - + + + + + + + + + 0 - + + + + + + + + + METHOD A srCD4 diluted into 96 well tray.

Add 2.5 x 103 TCID IHb.

Incubate at 37oC for 1 hour.

B Dextrin sulphate diluted into another well tray.

Add M8166 (2.5 x 105/ml).

Incubate at 37°C for 1 hour.

Then add A to B.

Read at 2 - 3 days when positive controls show >95% syncytia

Claims

1. An agent against HIV and related viruses, in dosage unit form, comprising CD4 or a CD4-like material and a polyanionic anti-HIV agent, the content of CD4 or CD4-like material in the agent being less than the anti-virally effective dose of the CD4 or CD4-like material alone.

2. The agent of Claim 1 wherein the content of CD4 or CD4-like material is less than one-tenth of the anti-virally effective dose of the Cd4 or CD4-like material alone.

3. The agent of Claim 1 wherein the content of CD4 or CD4-like material is less than one-hundredth of the anti-virally effective dose of the Cd4 or CD4-like material alone.

4. The agent of any of Claims 1 to 3 wherein the content of said polyanionic anti-HIV agent is less than the antivirally effective dose of the polyanionic anti-HIV agent alone. 5. According to Claim 13 or Claim 15, substantially as herein described. 19. The use of an agent according to Claim 8 or the use of an agent in the manufacture of a pharmaceutical composition

5. The agent of any of Claims 1 to 4 wherein said polyanionic anti-HIV agent is a sulphated polysaccharide.

6. The agent of Claim 5 wherein the sulphated polysaccharide is dextrin sulphate.

7. The agent of Claim 5 or 6 wherein said sulphated polysaccharide contains at least one sulphate group per saccharide unit.

8. The use of an agent according to any preceding claim against HIV-1 and related viruses.

9. The use of an agent, as claimed in Claim 8, wherein the agent is administered peritoneally. 10. According to Claim ^substantially as herein described. 20. CD4 or CD4-like material according to Claim 14 substantially as herein described.

10. The agent of any of Claims 1 to 7, adapted for intraperitoneal administration.

11. The agent of any of Claims 1 to 7, for use in the manufacture of a pharmaceutical composition against HIV-1 and related viruses.

12. A pharmaceutical composition containing the agent of any of Claims 1 to 7 and an inert carrier or diluent.

13. A method of treatment of a human or animal subject carrying the HIV-1 virus or a related virus, comprising administering to the subject a pharmaceutically effective amount of the agent of any of Claims 1 to 7. •Ε 913341

14. CD4 or CD4-like material, of an amount less than its usual anti-virally effective dose, and a polyanionic anti-HIV agent, for use in a method of treatment of a human or animal subject carrying the HIV-1 virus or a related virus in which the CD4 or CD4-like material and the polyanionic agent are administered to the subject one after the other, in any order. 15. A method of treatment of a human or animal subject carrying the HIV-1 virus or a related virus, comprising administering to the subject, one after the other but in any order, CD4 or a CD4-like material, of an amount less than its usual antivirally effective dose, and a polyanionic anti-HIV agent. 16. A method according to Claim 15, wherein the CD4 or CD4-like material is administered before the polyanionic anti-HIV agent. -1217. An agent against HIV and related viruses, in dosage unit form substantially as described in the Examples. 18. A method of treatment of a human or animal subject

15. 21. The features described in the foregoing specification or any obvious equivalent thereof, in any novel selection.