JPH03153632A - Pharmaceutical composition and method for preventing production of viii factor inhibiting agent - Google Patents

Abstract

PURPOSE: To obtain a medicinal composition suitable for administering to a human for effectively suppressing the production of factor VIII inhibitor by containing an immunocomplex consisting of a factor VIII antigenic component and a factor VIII inhibitor component. CONSTITUTION: This medicinal composition for suppressing the production of factor VIII inhibitor, contains an immunocomplex consisting of a factor VIII antigenic component and a factor VIII inhibitor component in a ratio that the factor VIII inhibitor component presents so as to block substantially all of the related binding sites of the factor VIII antigenic component [a molar ratio of the antigen to the inhibitor is (1:1)-(1:100), preferably (1:3)-(1:100)] and a pharmacologically permissible carrier or a diluent. As the above inhibitor component, an antibody obtained from a single patient or an antibody obtained from a plasma pooled from many donors are used and especially the former is preferable. As the amount of an administration of the antigen component, 1 nanogram to 10 microgram is suitable, and it is preferable to use a relatively small amount for an initial administration and increase later to a necessary amount for attaining a level sufficiently suppressing the production of the inhibitor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a pharmaceutical composition comprising a complex of a factor (I) antigen and a factor (I) proviso, and a method for inhibiting the production of a factor Xv'Ill inhibitor. Concerning their use in restraint.

Blood coagulation factor ~1 normally circulates at very low but satisfactory concentrations in plasma and plays an important role in the blood coagulation process. Unsatisfactory concentrations of Part II cause slow blood clotting and serious bleeding complications in people suffering from classic hemophilia, also known as hemophilia A. As a result, hemophiliacs are unable to stop bleeding even after minor trauma and suffer from many related diseases.

Hemophilia A has been treated for many years by administering commercially available factor II to raise the factor II concentration in the blood to normal levels.

Usually this therapy is quite effective and allows hemophiliacs to enjoy a normal life. Between 6 and 20% of hemophiliacs have immune systems that produce EI'1 inhibitors against factor I, however these individuals respond unsatisfactorily to incidental factor I treatment. . This is especially true for about two-thirds of patients who have inhibitors, who are called high responders. Injection of Factor II into these individuals raises inhibitor levels to very high levels.

Factor II inhibitors consist of alloantibodies against factor I and old factors. These antibodies are typically of the IgG class, and rarely of the JgM or IgA class. Inhibitors attack and neutralize commercial supplies of factor He1, rendering it ineffective in the blood clotting process. Inhibitor levels can be measured in Bethesda units.

Bleeding complications associated with factor II inhibitors are not limited to patients with hemophilia. Autoantibodies to factor II can occur in nonhemophilic patients with rheumatoid arthritis, systemic erythematous wax, or drug hypersensitivity, in parous women, and even in apparently healthy elderly people.

Symptoms similar to those associated with hemophilia occur in these individuals.

Although several therapies are known to combat the immunological response to factor II in hemophiliacs and their patients with factor II inhibitors, these therapies are not entirely satisfactory. Therapy with very high doses of Iff prisoners alone has been successful in the majority of patients, but is typically lengthy and expensive. Moderately high dose of factor ■ alone! It may be effective in a lower percentage of patients and usually in those with the lowest titers of inhibitor. Factor II or the so-called prothrombin? Therapy with M combinations is difficult to evaluate in the absence of specificity assays. The use of porcine factor 1/Tll instead of human factor 11 is only a temporary measure as it is highly immunogenic. Select formulations of pooled gamma globulin administered intravenously are effective in reducing inhibitor levels, but only in some cases. In vitro removal of inhibitors on protein A-Sepharose is laborious. Extracorporeal removal of the inhibitor and the combination of immunosuppressants, intravenous gamma globulin and factor II have recently shown success, but the immune system does not respond to Li for other reasons.
It is considered harmful to injured patients.

Accordingly, an object of the present invention is to provide a pharmaceutical composition and method for effectively inhibiting the production of factor Ⅰ inhibitors.

The purpose of the pond of the present invention is to be safe, relatively inexpensive, and
It is an object of the present invention to provide a pharmaceutical composition for inhibiting the production of a factor-1 inhibitor that achieves inhibition in a relatively short period of time.

Yet another object of the present invention is to provide pharmaceutical compositions and methods for substantially completely eliminating drug phase II inhibitors from a patient.

Other objects of the invention will be apparent from the above detailed description.

The present invention provides a pharmaceutical composition comprising a factor (I) antigen component, a factor (I) inhibitor component, and a pharmacologically acceptable carrier or diluent. satisfy the purpose of The antigen and inhibitor components are present in a ratio such that the relevant binding sites on the antigen are blocked by the inhibitor so that the antigen does not produce substantially any adverse immunological response when administered to the tongue. The composition is administered to a patient to inhibit production of factor-I inhibitor.

The present invention achieves a number of advantages over prior art therapies for controlling the development of inhibitors to the larvae. 1st
And most fundamentally, the invention acts at the causal level and often blocks the body's production of inhibitors.

Many patients show significant improvement after relatively short periods of treatment. Improvement is rapid and the inhibitor is eventually completely eliminated in the majority of cases.

Second, the present invention only requires a low dose of the second prisoner. Commercially prepared drugs are relatively expensive, and the reduced requirements of the present invention allow for cost savings over therapies requiring continuous administration of the agent. After the present invention stops the production of inhibitors, does the use of the normal operculum in conventional therapy effectively control hemophilia? ) 11.

Third, the compositions of the present invention have little, if any, toxicity by their nature. The immune complex is preferably formed with components already present in the patient or with synthetic components that closely mimic autologous components.

The other ingredients of the composition are pharmacologically tolerable and may be otherwise varied with considerable latitude to avoid possible side effects that may be specific to a particular individual. can. The simplicity and largely autologous nature of the composition allows the therapy of the present invention to be safely and effectively combined with prior art therapies if beneficial.

Fourth, the present invention avoids other drawbacks of conventional therapy, yet still yields comparable and usually best results. The present invention
It does not require drastic manipulations, such as in the case of plasma export separation, and it does not suppress existing immune defenses against antigens not associated with the disorder.

Still other benefits of the present invention will be readily apparent to those skilled in the art.

The specific mode of action by which this invention achieves its success is unknown, but it benefits from the emergence of factor II/factor II inhibitor immune complexes that are unavoidably present in mixtures of factor II and inhibitors. is hypothesized to be induced. This immune complex is believed to stimulate the production of anti-idiotype antibodies against the inhibitor. This anti-idiotypic antibody suppresses the production of the inhibitor in cells or perhaps humoral cells. This hypothesis is provided to allow a better understanding of the invention, but is not to be construed as limiting the scope of the claims.

Human factor Ⅰ has been isolated 1. It is purified and commercially available as Hemophil N1 from the Highland Division of Baxter Healthcare Corporation, Deerfield, Illinois. US Patent Application No. 32.800, filed March 31, 1987, describes a preferred method for producing this antigen. Since the inhibitor will react only with factor II, almost any preparation of factor Nl is suitable, even factor II in the form of a crude extract, as long as it does not contain toxic substances. However, pure or relatively pure preparations of Factor II are preferred because they are easier to assess and control the amount of Factor II present, which is important in controlling between doses.

- Once the first pup has been obtained, the inhibitor can be obtained from three species: (a) the immunized animal, (b) pooled plasma from individual blood donors or multiple donors, and (C) the patient's own blood. derived from possible sources. It is preferred to use inhibitors from the patient, in the sense that the patient usually has more inhibitor than the blood donor. On the other hand, the use of pooled plasma inhibitors is commercially desirable because it allows the production of prepackaged immune complexes without patient involvement. Despite this, the degree of idiotypic cross-reactivity present on inhibitory molecules from various individual plasma sources, such as those present in plasma pools, is variable and therefore influences the efficacy of treatment. It is possible.

Inhibitors of animal origin are generally the least desirable due to the risk of undesirable side effects.

Inhibitory properties are polyclonal or monoclonal;
- in particular in the form of immunoglobulin fractions such as F(ab")2. The use of polyclonal antibodies reduces the risk of antigenic reactions against unmasked antigenic determinants. For the production of monoclonal antibodies One method is published by Langoneet al k14.1986, Academic Press, Inc.
munochemical Techniques-P
atrl-Hybridoma Technology
and , 'Ionoclonai Antibodi
es', Methods in Enz molo
Ll vol, 121.

Inhibitors are preferably purified by well known techniques. Purification has the benefit of removing therapeutically non-relevant substances. One suitable purification technique involves specific adsorption on N1 prisoners immobilized by solid phase hecamping. The inhibitor is then recovered by elution under conditions that disrupt the immune complex, such as extreme pH conditions, or by use of a chaiotrobinoc agent. Because therapeutic formulations of Factor II may contain small amounts of the large protein known as Von Willebrand factor, agents of interest prepared in this manner can generate antibodies against this related protein without affecting the efficacy of the present invention. May contain small amounts.

The compositions of the invention are prepared by combining the primary drug with the inhibitor in a form appropriate for the particular mode of administration chosen. No. N for which the inhibitor is specific
Sufficient PQ-injurious agent should be used to block substantially all of the available binding sites of a single prisoner, so that there is virtually no antigenic effect by the factor when the composition is administered. The minimum amount of inhibitor is typically a molar equivalent to the reaction of Factor I7, and the inhibitor is preferably present in molar excess. The highest does not exist in the inhibitor foot, but
However, for safety reasons, a molar excess of up to about 100 is used. Even larger inhibitor excesses can be used, but this is a waste of valuable material. Therefore, the appropriate factor II to inhibitor molar ratio of j is about 11 to 1:100. The ratio is preferably at least 13 to 1:100.

nW-1i for preparing mixtures of factor II and inhibitors, avoiding the need for purification of factor II or [stage I inhibitors]
A popular method is the use of immunization. - In a specific example, the precipitate is prepared by incubating the crude immunoglobulin from the patient's plasma or serum with the first incubator and then centrifuging it. This precipitation process is enhanced by the addition of polymers such as polyethylene glycol and dextran, or biological reagents such as rheumatoid factor or complement factor C1q. These techniques are well known in the art.

The composition of the present invention contains, in addition to factor Ⅰ and an inhibitor, a component of pond. For injections, suitable additional ingredients include I
Contains human albumin to prevent Intoxicant 0 denaturation, anti-foam agents such as phenol, and adjuvants such as peptidoglycan.

Suitable liquid for the composition when in pourable form!
The U-form is water, or more preferably saline or buffered saline. In a preferred embodiment, the composition is a saline carrier of 9 g of sodium chloride per lindle;
or a buffered saline solution having a pH of 7.4. Suitable liquid bodies are, for example, neutral p I-1 and low ionic strength. The selection of other pharmaceutically acceptable carriers for use in the compositions is within the skill of those in the art.

The compositions of the present invention are prepared in various forms depending on the mode of administration. They are suitably formulated as sterile injectables, slow-release implants, protected enteric-coated capsules, or the like. Other suitable forms will be readily apparent to those skilled in the art.

When the composition is prepared in liquid form, the liquid is suitably a solution or a suspension. The liquid is stored in ampoules or
or lyophilized and reconstituted immediately before use. The compositions of the invention are fairly stable and can be stored for a limited time in sterile ampoules, usually at 4°C, or for extended periods at -20'C. Since factor 1 is highly susceptible to proteolytic digestion, the addition of proteolytic inhibitors is recommended!
j? The lifespan of the straw can be significantly increased. Freeze drying also increases shelf life.

The injectable compositions of the present invention are injected intrathecally, subcutaneously, intramuscularly and intravenously. The intratree route is preferred as it provides a suitable method of delivering the composition to the immune system of the patient being treated. The frequency of injections varies very widely, for example from a few days to every year, depending on the severity of the disease and the stage of treatment.

The potency of the composition is preferably expressed in terms of Factor I concentration and Factor I to inhibitor ratio. A suitable dosage range for the Factor II antigen component of the composition is from about 1 International Convict Unit per kilogram of body weight to about 100 International Convict Units per kilogram, and the factor II to inhibitor ratio is ■ Selected to mask the obvious immunogenic site of the factor. A dosage of about 1 nanogram to 10 micrograms is suitable.

The initial Phase XII prisoner dose is preferably relatively small;
The production of the inhibitor is then increased as necessary to a level that is sufficiently inhibited. Thus, a suitable treatment regimen requires an initial intravenous administration of 1 international factor II per kilogram and a -week later a second administration of 10 units per kilogram. Additional weekly doses are administered as needed;
and gradually increased to 100 units per kilogram if necessary to suppress N1 prisoner inhibitor formation.

It will be readily apparent to those skilled in the art that modifications to the presently described preparative techniques are suitable in the practice of the invention and are within the scope of the claimed invention. To more fully understand the invention, the following examples illustrate how it is made and used.

Example 1 Haemophil M, commercially available from the Baxter Highland Division of Glensol, Calif., is used as the factor II antigen component. This antigen is Ultrogel
AcA 44 and or U l troge IA
It is purified by gel filtration chromatography on c 54 (LKB) and, where appropriate, by specific immunoadsorption on immobilized polyclonal or monoclonal specific antibodies.

The antigen is then coupled to carboxylated agarose (CH Sepharose 4B; Pharmacia, Fine Chemicals) by carbodiimide.

For this purpose, the antigen is incubated with 0.1 M carbodiimide and carboxylated agarose at pH 4,5 for 24 hours at 21°C.

The remaining reactive groups on the solid phase are 21'C with 1M glycine.
Inactivation is achieved by incubation for 3 hours at . The immunoadsorbents were then both treated with 0.5M Na
0.1 M acetate buffer pH 4.0 containing Cl;
It is then washed alternately with O, IM carbonate buffer pH 8.3. To avoid elution of unwanted substances along with the antibody of interest, the gel is subjected to the elution conditions described below and to an additional wash with 3M ammonium thiocyanate before immunoadsorption.

The factor 5l inhibitor component is prepared from patient plasma as follows. Immunoglobulin fractions from each patient (
1-2 g) was added to the immunosorbent column (51111!;110
X2C; flow rate 20 ml/h) and the specific inhibitor antibodies are recovered after appropriate washing. Cleaning is carried out as follows.

1. Optical density at 2130 nm is 0. (Wash with PBS until it becomes 12 or less.

2. Washing with PBS containing IM NaCl to remove non-specific adsorption.

3. Washing with 150 ml of 9 g/n NaC.

4. Citric acid, 1) 82.7 and subsequent (7 volumes with aliquots) of 50 ml of PBS.

Continue each new wash and ejection step until no protein is detected in the flow.

Fractions eluted with citric acid and PBS were immediately pooled, neutralized by dropwise addition of 2M 1-Lis-HCl buffer, concentrated on a YMIO ultrafiltration membrane, and dialyzed against PBS for 48 h. Ru. The eluate was then passed through a 0.22 micron filter into a sterile vial at 4°C.
stored at C. The immunoadsorbent is washed with 3M ammonium thiocyanate and finally with 3100 ml of PB. All buffers are passed through a 0.22 micron filter.

The neutralizing capacity of an inhibitor is determined by its ability to neutralize the procoagulant activity of factor II. A complex of Hemophil M and patient-derived antibody is formed at an antigen-to-weight ratio of 1:3 using the neutralizing ability information thus obtained.

Antigen and inhibitor are mixed in 9 g/p of saline containing 0.3% human serum albumin and 0.4% phenol. All liquids are passed through a sterile 0.22 micron filter and handled under aseptic conditions. The final volume is 2 ml and contains 300 micrograms of I0 agent and 100 microdulums of antigen. The injectable solution so prepared is stored in sealed vials at 4 °C until use. .

Example 2 A composition is prepared according to Example 1, except that the mixture contains 10 micrograms of antigen and the antigen to inhibitor ratio is 1:3.

Example 3 A composition is prepared according to Example 1, except that the mixture contains 1 microgram of antigen and the antigen to inhibitor ratio is 1:30.

Example 4 A composition is prepared according to Example 1, except that the mixture contains 0.1 micrograms of antigen and the antigen to inhibitor ratio is 1:10.

Example 5 The mixture contains 0.1 micrograms of antigen and the antigen to dross ratio is 1:3! Example 1 except:
A composition is prepared according to the following formula.

Example 6 A formulation is prepared according to Example 1, except that the mixture contains 1000 nanograms of antigen and the antigen to inhibitor ratio is 1=1.

Example 7 A composition is prepared according to Example 1, except that the mixture contains 100 nanograms of antigen and the antigen to inhibitor ratio is 1=60.

Example 8 A composition is prepared according to Example 1, except that the mixture contains 10 nanograms of antigen and the antigen to [;II inhibitor ratio is 80.

Example 9 A composition is prepared according to Example 1, except that the mixture contains 1 nanogram of antigen and the antigen to 1:li inhibitor ratio is 1:100.

Example 10 A composition is prepared according to Example 1t, except that the mixture contains 50 nanograms of antigen and the antigen to 1:[1 agent ratio is 1:20.

Example 11 A composition is prepared according to Example 1, except that the mixture contains lO micrograms of antigen and the antigen to inhibitor ratio is 1:40.

Example 12 A composition is prepared according to Example 1, except that the γkV compound contains 500 nanograms of antigen and the antigen to inhibitor ratio is 1:5.

Example 13 Immunoadsorbent was prepared as described in Example 1, except that factor 11 antigen was prepared by Baton, Rodrigue.
z, Vehar.

Proteolytic Processing of
Human Factor V11'+8ioche
mistr, 25. pp, 505-512 (
It is a form of factor Ⅰ fragment generated by proteolytic cleavage of factor Ⅰ, as taught by (1986). Antibodies were collected from pooled normal plasma (donor 10 without pooling).
prepared from humans). Neutralizing capacity is determined and the conjugate is formed and formulated as described in Example 2.

Example 14 The immunoadsorbent is prepared as described in Example 1, but the inhibitor is Gammagar F (Baxfow, Highland Division, Glensor, Calif.). Neutralizing capacity is determined and the conjugate is formed and formulated as described in Example 3.

Example 15 Antibodies were +i! as described in Example 10. '11, but the complex is similar to Toole et al., Natur.
e+dan2. -342348 (1984) using factor II antigen produced by &II recombinant DNA technology.

Example 16 The antigen-antibody complex was 3I described in Example 12: sea urchin,
However, it has been developed using mouse monoclonal antibodies directed against hemophil M and factor 11 Q;
Prepared as taught in U.S. Patent Application No. 32,800, filed Mar. 31, 1987. Mouse monoclonal antibody is the antibody used to purify Haemophil M. Monoclonal antibodies from other suckling species, including humans, may also be used.

Example 17 Antigen-antibody complexes were prepared as described in Example 1, but the bL source was prepared as described in Toole et al, Nature+
312+ pp.

342-348 (1984) and then prepared by standard techniques.
ab')2 antibody fragments and are synthetically prepared by organic synthesis techniques.

Example 18 The conjugate prepared as described in the example above was
Ironically injected into hemophilia A patients who have factor antibodies. In each case, the first dose contains an amount of the factor antigen component ■ equivalent to one International Unit of Convict per kg of the patient's body weight. The second dose, administered one week later, contains a Factor ■ antigen component equivalent to 10 International Units of Factor ■ per kg of patient body weight. One week after this second dose, the patient's plasma did not contain any detectable anti-factor II antibodies, and the response to intravenously injected factor II was normally expected in a person with hemophilia. and the patient is then treated on demand at the second prison.

Example 19 Initial treatment of patients is as described in Example 18.

One week after the second dose, the patient's plasma still contains anti-factor ■ antibodies. First proviso factor 2 per kg of patient weight
A complex containing the equivalent of 0 international units is injected sarcastically.

In a similar manner, in subsequent weeks, when anti-factor II antibodies are still detectable in the patient's plasma, increasing doses of ff1
(International Units such as 30,40°50) is administered sarcastically. The highest dose used is the patient's weight in kg
This is equivalent to 100 international units. When anti-Prison IV antibodies are no longer detectable in the patient's plasma, on-demand intravenous vIIl factor therapy is initiated as described in Example 18.

Example 20 Antigen-antibody complex treatment is performed as described in Example 19. However, upon the first intravenous infusion treatment with Factor II, it is determined that the half-life and/or recovery of the injected Factor II is less than would be expected in a hemophilia A5 individual. The patient then received 200 doses per kg of body weight daily until the response to the infusion was satisfactory.
Treated with international doses of intravenous fluids. Patients were then given 50 mg/kg twice or three times a week as clinical responses were recorded.
Treated prophylactically with 0 units.

Example 21 A patient did not previously have a deficiency of factor II, but currently has a hemorrhagic disease due to autoantibodies against factor factor II. The patient is Example 1
8.19 and 20. These patients usually respond more readily to such treatment than hemophiliacs, and the prophylactic regimen described in Example 20 is rarely, if ever, necessary.

Example 22 Subcutaneous injection of the conjugate prepared as described in the above example at a dose containing an amount of the prisoner antigen component of factor II equivalent to 100 international units of factor per kg of body weight of the patient.6. ) Pitch 4 times twice a day. A total of 20 doses will be administered.

Example 23 A conjugate prepared as described in the above example is injected subcutaneously at a dose containing an amount of the factor 2 antigen component equivalent to 20 international units of factor 2 per kg of patient body weight. The amount is administered three times a day. A total of 15 doses are administered.

Example 24 A conjugate prepared as described in the above example is injected subcutaneously at a dose containing the equivalent of 80 international units of prisoner antigen component per kg of body weight of the individual. . The dose is administered once a day. A total of 10 doses will be administered.

Example 25 A conjugate prepared as described in the above example is injected subcutaneously in a dose containing an amount of the factor II antigen component equivalent to 60 international units of factor II per kg of patient body weight. The dose is administered daily. A total of 4 doses will be administered.

EXAMPLE 26 A conjugate prepared as described in the above example is injected subcutaneously at a dose containing the equivalent of 40 International Units of the IPC antigen component per kg of patient body weight. The dose is administered only once.

Example 27 A complex prepared as described in the example above was
The patient is given a sarcastic injection at a dose containing 50 r6T units of Factor I antigen per gram of the patient's body weight. The dose is administered every three months. A total of 2 doses will be administered.

Example 28 The conjugate prepared as described in the above example was applied to
Inject subcutaneously in a dose containing the amount of factor antigen component.

The dose is given annually. A total of 5 doses will be administered.

EXAMPLE 2 Treatment proceeds as described in the previous example, but as described by Nilsson et al., N., En, J.
, Med, 318゜pp, 9□17-950 (
1988), supplemented with intravenous immunoglobulin in a manner known to those skilled in the art.

Example 30 Treatment proceeds as described in previous examples, but is augmented by conventional treatment with cyclophosphamide as taught in the Nilsson et al reference.

Example 31 Treatment proceeds as described in previous examples, but is augmented with both intravenous immunoglobulin and cyclophosphamide.

The above examples describe a number of methods for preparing the antigen and drug components, respectively, and these and other methods are employed in various combinations to obtain the compositions of the invention. The factor ■ component may suitably be (1) purified by classical '(I'5) from a human plasma pool, (2) purified by immunoadsorption from a human plasma pool, (3) genetically engineered,
(4) No. 51 produced by the above method (1) or 3)
It is foreseen that it may be produced by peptides or small protein fragments obtained from factor preparations, and (5) synthetically produced peptides.

One of these methods for producing the antigen component includes any one of the following forms foreseen for the inhibitor component (1).
Purified 1 (11: rr agent,
(2) purified inhibitors from plasma pools, (3) F(ab″)2 fragments of purified preparations, (4) monoclonal antibodies, and (5) chimeric antibodies, i.e., binding sites obtained from animal sources and human As used in the claims, factor I antigen components refer to factor I antigen components, regardless of the manner in which they are made. The 1st prisoner molecule or fragment containing the factor V antigenic determinant is sampled.

Factor νl inhibitors, as used in the claims, are defined as
Refers to antibodies and fragments that contain an immunogenic binding site for factor II.

Having illustrated the invention with respect to several specific embodiments,
Those skilled in the art will understand that the first factor (I) is administered at a ratio of factor (I) to 1 and the harmful agent to be 1.
It is taught that elements of the invention may be modified, such as the factor 1↓ body or diluent, the method of administration and periodicity appropriate to inhibit factor ↓ production.

It will be apparent to those skilled in the art that these and other modifications are within the spirit and scope of the invention.

Claims (13)

[Claims] (1) an immune complex consisting of a factor VIII antigen component and a factor VIII inhibitor component, said components being arranged in such a ratio that said inhibitor component blocks substantially all relevant binding sites of said antigen component; A pharmaceutical composition suitable for administration to humans for inhibiting factor VIII production, characterized in that it is present in a pharmaceutical composition and comprises a pharmacologically acceptable carrier or diluent. (2) The composition of item 1, wherein the antigen component is factor VIII prepared from human plasma. (3) The composition of item 1, wherein the antigen component is factor VIII produced by recombinant DNA technology. (4) The composition of item 1, wherein the antigen component is a factor VIII fragment. (5) The composition of item 1, wherein the inhibitor component is an antibody obtained from a single patient. (6) The composition of item 1, wherein the inhibitor component is an antibody obtained from pooled plasma of multiple donors. (7) The composition of item 1, wherein the inhibitor component is an F(ab')_2 antibody fragment. (8) The composition of item 1, wherein the inhibitor component is a chimeric antibody. (9) The inhibitor component is a monoclonal antibody.
composition of the term. (10) The composition of clause 1, wherein said inhibitor component is present in molar excess with respect to said Factor VIII antigen component. (11) The molar ratio of antigen to inhibitor components is about 1:1 to about 1
:100. (12) The composition of item 11, wherein the ratio is about 1:3. (13) The composition of claim 1, wherein the antigenic component is present in a dosage of about 1 nanogram to about 10 micrograms.