THROMBOSIS RESEARCH 61; 285290,199l 0049-3848/91 $3.00 + .OO Printed in the USA. Copyright (c) 1991 Pergamon Press pk. All rights reserved.
COMPARATIVE
OF THE PHARMACOKINETICS FACTOR VIII CONCENTRATES
EVALUATION
MONOCLONAL
OF THREE
MORFINI M., MANNUCCI P.M.*, LONG0 G., CINOTTI S., MESSORI A. Hematology Department and Hemophilia Center, University Hospital of Florence,I-50134 Firenze,Italy and *Angelo Bianchi Bonomi Hemophilia & Thrombosis Center, Institute of Internal Medicine, Milan, Italy. (Received
19.10.1990;
accepted
in original
form 20.11 .1990 by Editor G.G. Neri Seneri)
Abstract
Hemofil M, Monoclate HT, and Monoclate P are high-purity Factor VIII concentrates, obtained from plasma by immunoaffinity chromatography with monoclonal antibodies specific for Factor VIII (Hemofil M) or von Willebrand Factor (Monoclate HT and Monoclate P). The concentrates are subjected to virucidal treatments: a solvent/detergent method (TNBP/Na-cholate) for Hemofil M, heating in the lyophilized state and in solution (pasteurization) for Monoclate HT and Monoclate P, respectively. Since these differences in the manufacturing process might result in different in vivo characteristics of the concentrates, we compared their in vivo behavior in a crossover, single-dose, pharmacokinetic study performed in 10 non-bleeding patients with severe hemophilia A. The experimental conditions (Factor VIII dose, number and timing of blood sampling, Factor VIII assay methods, calculation of pharmacokinetic parameters) were identical for the three products.The results showed that the clearance, the mean residence time, and the volume of distribution did not differ among the three products.
INTRODUCTION Hemofil M, Monoclate HT, and Monoclate P are high-purity Factor VIII concentrates obtained from plasma by immunoaffinity chromatography with monoclonal antibodies specific for Factor VIII (Hemofil M) or for von Willebrand Factor (Monoclate HT and Monoelate P). All three concentrates are subjected to virucidal treatments: a solvent/detergent method (TNBP/Na-cholate) for Hemofil M, heating in the lyophilized state (dry-heating) or heating in solution (pasteurization) for Monoclate HT and MonoKey words: Monoclonal
Factor VIII concentrates, 285
Pharmacokinetics
286
FACTOR VIII MONOCLONAL CONCENTRATES
Vol. 61, No. 3
elate P, respectively. This study was conducted to assess whether or not differences in the manufacturing process and virucidal methods of the three products might result in a different behavior of plasma concentrations of Factor VIII after infusion into hemophiliacs. MATERIALS AND METHODS Monoclonal concentrates Hemofil M (Baxter-Hyland, Glendale, Ca, USA)is obtained by immunoaffinity chromatography with anti-human Factor VIII monoclonal antibodies (1) ; the concentrate is subjected to solventdetergent (TNBP/Na-cholate) treatment according to the New York Blood Center method (2). Monoclate HT and Monoclate P (both manufactured by Armour, Kankakee, IL, USA) are obtained by immunoaffinity chromatography with anti-human von Willebrand Factor monoclonal antibodies (3). Monoclate HT is dry-heated at 60°C for 30 h, Monoclate P is pasteurized at 60°C for 10 h (4,5). The specific activity of these concentrates in eluate after immuno- affinity chromatography is more than 3,000 I.U./mg total protein. Human albumin is deliberately added to concentrates before lyophilization to stabilize Factor VIII. Accordingly, the specific activity of the concentrates in their final formulation averages 3.4 I.U. of Factor VIII/mg total protein for Hemofil M and 6.1 I.U./mg for both Monoclate HT and P (6). Study design The in vivo study of the three concentrates was conducted as an open-label single-dose pharmacokinetic study involving 10 patients with severe hemophilia A. Each patient was randomly allocated to a treatment sequence using a cross-over Latin-square design. The minimum interval between two consecutive infusions was one week. The criteria for patients' inclusion were the following: a) age over 12 years: b) body weight over 25 kg: c) baseline Factor VIII:C activity less than 0.01 I.U./ml; d) previous treatment with at least two different intermediate-purity The exclusion criteria were the folFactor VIII concentrates. lowing: a) presence of circulating Factor VIII inhibitors: b) treatment with Factor VIII concentrate during the week preceding the entry into the study: c) presence of bleeding disorders other than hemophilia: d) presence of other chronic illnesses (e.g. renal, hepatic, gastrointestinal, pulmonary or cardiovascular with the exclusion of chronic hepatitis: e) presence of disease) alcohol or drug abuse or seizure disorders: f) use of acetylsalicylic acid or nonsteroidal anti-inflammatory drugs during the 10 days preceding the study. Concentrate administration Each concentrate was injected at the dose of 25 I.U./kg body weight over 10 minutes. A syringe pump was used for the infusion. Blood samples Six ml of blood were drawn by clean venopuncture from the forearm at the following times: before infusion and 0.08, 0.25, 0.5, 1, 2, 3, 6, 8, 12, 24 and 36 hours after the end of infusion. An aliquot of 1.5 ml of blood was transferred into a vacutainer tube with EDTA for haematocrit determination. The remaining 4.5 ml were transferred into a tube containing tri-sodium
Vol. 61, No. 3
FACTOR VIII MONOCLONAL CONCENTRATES
287
citrate 3.8% (w/v) for Factor VIII:C assay: this aliquot was immediately centrifuged (for 20 minutes at 1200 g and 4'C) and platelet-poor plasma was stored in plastic tubes at -7OOC. Dose calculation The dose actuallv infused in each exoeriment was determined from the amount of injected product (difference in weight of syringe before and after infusion) and from the Factor VIII potency of the concentrate as declared by the manufacturer. Factor VIII:C assay Plasma concentrations of Factor VIII:C were assayed by one stage clotting assay (7). Each sample was assayed in three dilutions and each dilution in duplicate by the same operator. Activated partial thromboplastin reagent (Actin FS, Dade), Factor VIII:C immunodepleted plasma (Dade), Reference Factor VIII 100% (Immuno) calibrated against International Human Reference plasma were used. All Factor VIII:C determinations were performed manually. Calculations were carried out using the parallel-line method (8): Pharmacokinetic analysis Each single-dose pharmacokinetic curve of Factor VIII was analyzed using both compartmental and non-compartmental methods. The in vivo recovery was also calculated from each curve. Compartmental methods: the basic pharmacokinetic parameters of the two-compartment open model (alpha and beta half-life) were estimated using a nonlinear least square iterative method (g-10). The concentration values were weighted statistically, taking weight as the reciprocal of concentration. The F-ratio test was employed to assess whether individual decay curves were monophasic or biphasic. Curves showing no evidence of biphasic decay were excluded from the calculation of the two-compartment parameters. Non-compartmental (model-independent) method: this pharmacokinetic method of analysis is based on the calculation of the following three parameters: 1. Total body clearance: 2. Volume of distribution estimated by the area method (Vd-area); 3. Mean residence time (MRT). Half-life is calculated indirectly as MRT/1.443. The estimation of Clearance, Vd-area, and MRT from single-dose experimental data is based on the calculation of the area under the curve (AUC, where the "curve" is a plot of the Factor VIII concentration vs. time) and of the area under the moment curve (AUMC, where the "moment curve" is a plot of the product of concentration and time vs. time). The procedures for calculating model independent parameters have been previously described in detail (9,11,12). Calculation of in vivo recovery: the plasma volume of each patient was estimated to correspond to 41 ml multiplied by the body weight expressed in kilograms. In vivo recovery was calculated as the ratio of the plasma Factor VIII:C activity measured after the end of infusion (measured peak value) and the Factor VIII activity expected theoretically (expected peak value). The measured peak value was determined as the maximum Factor VIII:C concentration measured in the three samples drawn at 0.25, 0.5 and 1 hour after the end of infusion. The expected peak value was calculated by dividing the administered amount of Factor VIII:C by the patient's plasma volume (13).
Vol.61,No. 3
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288
RESULTS Table
1 summarizes
the
results
of the TABLE
pharmacokinetic
study.
1
Pharmacokinetic parameters of monoclonal Factor VIII concentrates, according model-independent and compartmental analysis. Monoclate P
Dose
(IU) 26.2+2.1 Peak (IU/dL) 56.9T17.2 Time of peak (hr) 0.2920.30 Model-independent parameters: Clearance 4.9+3.1 (ml/h/kg) Mean residence time (h) 17.6T6.4 Half-life (h) 12.2T4.4 Vd Area 72.5722.9 (ml/kg) In Vivo Recovery (%) 100.8'32.4 Compartmental parameters:* biphasic decay curves 7 alpha half-life (h) 1.25+0.96 beta half-life (h) 14.73z7.13
Monoclate HT
Hemofil M
p-value by Friedman's two-way ANOVA
30.0+5.8 53.459.0 0.2050.17
28.8+4.8 53.8513.1 0.22+0.17
0.25 0.50 0.40
5.0+1.6 15.7T4.7 10.9T3.2 75.9712.5 82.7x10.0
5.1+2.5 15.2T4.9 10.573.4 74.4T24.6 87.1T23.4 -
0.30 0.49 0.49 0.49 0.15
6 1.83+2.27 11.4523.46
8 0.92+0.66 11.7514.46
0.25 0.35
*Reported only for curves showing evidence of biphasic decay.
Friedman's two-way analysis of variance showed no significant differences in the model-independent and compartmental pharmacokinetic parameters of the three monoclonal concentrates. The percentage of curves showing evidence of biphasic decay was 60% for Monoclate HT, 70% for Monoclate P, and 80% for Hemofil M. Monoclate P showed the highest in vivo recovery, the lowest clearance and the longest mean residence time (and half-life). In addition, despite the fact that the average infused dose of Monoelate P was slightly lower than that of Monoclate and Hemofil M, the peak values observed after Monoclate P were on average higher. While these data seem to indicate that Monoclate P has a slightly better pharmacokinetic profile, none of the differences achieved statistical significance. the pharmacokinetic parameters determinated We also compared for the three monoclonal concentrates with those previously obtained for intermediate-purity concentrates. In 1988, Messori et al. (10) reported the following values (mean+SD) calculated from a series of 87 single-dose pharmacokinetic curves: clearance (h) = 11.00+4.9; Vd-area (ml/h/kg) = 3.85z1.94; half-life (ml/kg) = 58.20+21.3. The intermediate-purity products included in that evaluation were Kryobulin (N=39) and Kryobulin TIM3 (N=17) (Immuno, Vienna, Austria), Koate HT (N=18) (Cutter, Berkeley, Ga), and Hemofil (N=13) (Hyland, Glendale, Ca). The Comparison of these data with those reported in Table 1 indicates that the pharmacokinetic characteristics of the monoclonal concentraHowever, tes are similar to those of conventional concentrates.
Vol. 61, No. 3
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289
all monoclonal concentrates seem to have a slightly higher clearance and a larger Vd-area than traditional factor VIII concentrates. In addition, Monoclate P shows a somewhat longer half-life (and MRT) in comparison with the other (monoclonal and intermediate-purity) products. DISCUSSION The three monoclonal concentrates evaluated in this study diffor Factor VIII purification fer substantially in the procedures and virus inactivation. In addition, although their specific activity with respect to the content of total protein, fibrinogen or immunoglobulins is similar, their content in von Willebrand Factor Antigen (vWFAg) differs greatly inasmuch the vWFAg/Factor VIII:C ratio is 0.02 in Hemofil M and around 0.10 in Monoclate HT (6). Since vWFAg is known to play a key role in Factor VIII:C stabilization both in vivo and in vitro, the differences in vWFAg content might result in differences in pharmacokinetic behavior of the concentrates. This study, however, showed no clear difference in the pharmacokinetics of Monoclate HT, Monoclate P, and Hemofil M, thus indicating that the different fractionation methods, virucidal methods and contents of vWFAg of the concentrates do not affect the rate of Factor VIII:C disappearance from plasma. Similar preliminary results have been recently obtained in another cross-over study for two pasteurized concentrates, differing widely in their vWFAg content (14,15). Finally, the trend towards a faster Clearance and larger Vdarea for monoclonal products, compared with intermediate-purity concentrates deserves some comments. While on the one hand this finding suggests that monoclonal concentrates have a larger extra-vascular diffusion, on the other it remains at present unknown if the diffusion of Factor VIII:C in the extra-vascular space is beneficial in terms of hemostatic efficacy.
REFERENCES 1. Antihemophilic Factor (Human), Method M, Monoclonal purified. Baxter Health Care Corporation, Hyland Division, Glendale, CA, USA, 1988. 2. HOROWITZ, B., WIEBE, M.E, LIPPIN, A., STRYKER, M.H. Inactivation of viruses in labile blood derivatives. I-Disruption of lipid-enveloped viruses by tri(n-butyl)phosphate detergent combinations. Transfusion 25,516-522, 1985.
3. ZIMMERMAN, T.S. Purification of Factor VIII by monoclonal Antibody Affinity Chromatography. Semin. Hemat., 25, Suppl. 1, 25-26, 1988. 4. SCHREIBER, A.B. The preclinical characterization of Monoelate Factor VIII:C antihemophilic factor (Human). Semin. Hemat., 25, Suppl. 1, 27-32, 1988.
290
FACTOR VIII MONOCLONAL CONCENTRATES
Vol. 61, No. 3
5. HRINDA, M.E., FELDMAN, F., SCHREIBER, A.L. Preclinical characterization of a new pasteurized monoclonal antibody purified Factor VIIIC. Semin. Hemat., 27, Suppl. 2, 19-24, 1990.
6. MORFINI, M., RAFANELLI, D., FILIMBERTI, E., CINOTTI, S., PIAZZA, E., LONGO, G. AND ROSS1 FERRINI, P. Protein content and Factor VIII complex in untreated, treated and monoclonal concentrates. Thromb. Res., 56, 169-178, 1989. 7. LANGDELL, R.D, WAGNER, R.H, BRINKHOUS, K.M. Effect of antihaemophilic factor on one-stage clotting test. J Lab Clin Med 1953;41:637-41. 8. WILLIAMS, K.N., DAVIDSON, J.M.F., INGRAM, G.I.C. A computer program for the analysis of parallel-lines bioassay of clotting factors. Br. J. Haematol., 31, 13-23, 1975.
9. MESSORI, A, LONGO, G., MATUCCI, M., MORFINI, M., ROSS1 FERRINI, P. Clinical pharmacokinetics of Factor VIII in patients with classic hemophilia. Clin. Pharmacokinet., 13,365-380, 1987. 10. MESSORI, A, LONGO, G., MORFINI, M., CINOTTI, S., FILIMBERTI, E ., GIUSTARINI, G., ROSS1 FERRINI. P. Multivariate analysis of factors governing the pharmacokinetics of exogenous Factor VIII in hemophiliacs. Eur. J. Clin. Pharmacol., 35, 663-668, 1988. 11. MATUCCI, M., MESSORI, A., DONATI-CORI, G., LONGO, G., VANNINI, S., MORFINI, M., TENDI, E., ROSS1 FERRINI, P. Kinetic evaluation of four Factor VIII concentrates by model-independent methods. Stand. J. Haematol. 34, 22-28, 1985. 12. LONGO, G., MATUCCI, M., MESSORI, A., MORFINI, M., ROSS1 FERRINI. P.. Pharmacokinetics of a new heat-treated concentrate of Factor VIII estimated by model-independent methods. Thromb. Res., 42, 471-476, 1986. 13. MORFINI, M., MESSORI, A., LONGO, G., CINOTTI, S., MATUCCI, M ROSS1 FERRINI, P. Half-life and in vivo recovery of heated Fa&or VIII Lancet, II, 571-572, 1986.
14. SCHIMPF, K., REIS, T. Comparison of recovery and half-life of a new factor VIII high-purity concentrate (FVIII C HS) with a factor VIII HS (Haemate P). Ricerca Clin. Lab., 16, 231, 1986. 15. BLOMBACK, M., CINOTTI, S., LONGO, G., MESSORI, A., MORFINI, SCHIMPF, K. Pharmacokinetics of two pasteurized factor VIII M study on the reproducibility of co&entrates: a multi-center parameters using different assay methods. XIX International Congress of World Federation of Hemophilia, Washington D.C., August 14-19, 1990.
COMPARATIVE
OF THE PHARMACOKINETICS FACTOR VIII CONCENTRATES
EVALUATION
MONOCLONAL
OF THREE
MORFINI M., MANNUCCI P.M.*, LONG0 G., CINOTTI S., MESSORI A. Hematology Department and Hemophilia Center, University Hospital of Florence,I-50134 Firenze,Italy and *Angelo Bianchi Bonomi Hemophilia & Thrombosis Center, Institute of Internal Medicine, Milan, Italy. (Received
19.10.1990;
accepted
in original
form 20.11 .1990 by Editor G.G. Neri Seneri)
Abstract
Hemofil M, Monoclate HT, and Monoclate P are high-purity Factor VIII concentrates, obtained from plasma by immunoaffinity chromatography with monoclonal antibodies specific for Factor VIII (Hemofil M) or von Willebrand Factor (Monoclate HT and Monoclate P). The concentrates are subjected to virucidal treatments: a solvent/detergent method (TNBP/Na-cholate) for Hemofil M, heating in the lyophilized state and in solution (pasteurization) for Monoclate HT and Monoclate P, respectively. Since these differences in the manufacturing process might result in different in vivo characteristics of the concentrates, we compared their in vivo behavior in a crossover, single-dose, pharmacokinetic study performed in 10 non-bleeding patients with severe hemophilia A. The experimental conditions (Factor VIII dose, number and timing of blood sampling, Factor VIII assay methods, calculation of pharmacokinetic parameters) were identical for the three products.The results showed that the clearance, the mean residence time, and the volume of distribution did not differ among the three products.
INTRODUCTION Hemofil M, Monoclate HT, and Monoclate P are high-purity Factor VIII concentrates obtained from plasma by immunoaffinity chromatography with monoclonal antibodies specific for Factor VIII (Hemofil M) or for von Willebrand Factor (Monoclate HT and Monoelate P). All three concentrates are subjected to virucidal treatments: a solvent/detergent method (TNBP/Na-cholate) for Hemofil M, heating in the lyophilized state (dry-heating) or heating in solution (pasteurization) for Monoclate HT and MonoKey words: Monoclonal
Factor VIII concentrates, 285
Pharmacokinetics
286
FACTOR VIII MONOCLONAL CONCENTRATES
Vol. 61, No. 3
elate P, respectively. This study was conducted to assess whether or not differences in the manufacturing process and virucidal methods of the three products might result in a different behavior of plasma concentrations of Factor VIII after infusion into hemophiliacs. MATERIALS AND METHODS Monoclonal concentrates Hemofil M (Baxter-Hyland, Glendale, Ca, USA)is obtained by immunoaffinity chromatography with anti-human Factor VIII monoclonal antibodies (1) ; the concentrate is subjected to solventdetergent (TNBP/Na-cholate) treatment according to the New York Blood Center method (2). Monoclate HT and Monoclate P (both manufactured by Armour, Kankakee, IL, USA) are obtained by immunoaffinity chromatography with anti-human von Willebrand Factor monoclonal antibodies (3). Monoclate HT is dry-heated at 60°C for 30 h, Monoclate P is pasteurized at 60°C for 10 h (4,5). The specific activity of these concentrates in eluate after immuno- affinity chromatography is more than 3,000 I.U./mg total protein. Human albumin is deliberately added to concentrates before lyophilization to stabilize Factor VIII. Accordingly, the specific activity of the concentrates in their final formulation averages 3.4 I.U. of Factor VIII/mg total protein for Hemofil M and 6.1 I.U./mg for both Monoclate HT and P (6). Study design The in vivo study of the three concentrates was conducted as an open-label single-dose pharmacokinetic study involving 10 patients with severe hemophilia A. Each patient was randomly allocated to a treatment sequence using a cross-over Latin-square design. The minimum interval between two consecutive infusions was one week. The criteria for patients' inclusion were the following: a) age over 12 years: b) body weight over 25 kg: c) baseline Factor VIII:C activity less than 0.01 I.U./ml; d) previous treatment with at least two different intermediate-purity The exclusion criteria were the folFactor VIII concentrates. lowing: a) presence of circulating Factor VIII inhibitors: b) treatment with Factor VIII concentrate during the week preceding the entry into the study: c) presence of bleeding disorders other than hemophilia: d) presence of other chronic illnesses (e.g. renal, hepatic, gastrointestinal, pulmonary or cardiovascular with the exclusion of chronic hepatitis: e) presence of disease) alcohol or drug abuse or seizure disorders: f) use of acetylsalicylic acid or nonsteroidal anti-inflammatory drugs during the 10 days preceding the study. Concentrate administration Each concentrate was injected at the dose of 25 I.U./kg body weight over 10 minutes. A syringe pump was used for the infusion. Blood samples Six ml of blood were drawn by clean venopuncture from the forearm at the following times: before infusion and 0.08, 0.25, 0.5, 1, 2, 3, 6, 8, 12, 24 and 36 hours after the end of infusion. An aliquot of 1.5 ml of blood was transferred into a vacutainer tube with EDTA for haematocrit determination. The remaining 4.5 ml were transferred into a tube containing tri-sodium
Vol. 61, No. 3
FACTOR VIII MONOCLONAL CONCENTRATES
287
citrate 3.8% (w/v) for Factor VIII:C assay: this aliquot was immediately centrifuged (for 20 minutes at 1200 g and 4'C) and platelet-poor plasma was stored in plastic tubes at -7OOC. Dose calculation The dose actuallv infused in each exoeriment was determined from the amount of injected product (difference in weight of syringe before and after infusion) and from the Factor VIII potency of the concentrate as declared by the manufacturer. Factor VIII:C assay Plasma concentrations of Factor VIII:C were assayed by one stage clotting assay (7). Each sample was assayed in three dilutions and each dilution in duplicate by the same operator. Activated partial thromboplastin reagent (Actin FS, Dade), Factor VIII:C immunodepleted plasma (Dade), Reference Factor VIII 100% (Immuno) calibrated against International Human Reference plasma were used. All Factor VIII:C determinations were performed manually. Calculations were carried out using the parallel-line method (8): Pharmacokinetic analysis Each single-dose pharmacokinetic curve of Factor VIII was analyzed using both compartmental and non-compartmental methods. The in vivo recovery was also calculated from each curve. Compartmental methods: the basic pharmacokinetic parameters of the two-compartment open model (alpha and beta half-life) were estimated using a nonlinear least square iterative method (g-10). The concentration values were weighted statistically, taking weight as the reciprocal of concentration. The F-ratio test was employed to assess whether individual decay curves were monophasic or biphasic. Curves showing no evidence of biphasic decay were excluded from the calculation of the two-compartment parameters. Non-compartmental (model-independent) method: this pharmacokinetic method of analysis is based on the calculation of the following three parameters: 1. Total body clearance: 2. Volume of distribution estimated by the area method (Vd-area); 3. Mean residence time (MRT). Half-life is calculated indirectly as MRT/1.443. The estimation of Clearance, Vd-area, and MRT from single-dose experimental data is based on the calculation of the area under the curve (AUC, where the "curve" is a plot of the Factor VIII concentration vs. time) and of the area under the moment curve (AUMC, where the "moment curve" is a plot of the product of concentration and time vs. time). The procedures for calculating model independent parameters have been previously described in detail (9,11,12). Calculation of in vivo recovery: the plasma volume of each patient was estimated to correspond to 41 ml multiplied by the body weight expressed in kilograms. In vivo recovery was calculated as the ratio of the plasma Factor VIII:C activity measured after the end of infusion (measured peak value) and the Factor VIII activity expected theoretically (expected peak value). The measured peak value was determined as the maximum Factor VIII:C concentration measured in the three samples drawn at 0.25, 0.5 and 1 hour after the end of infusion. The expected peak value was calculated by dividing the administered amount of Factor VIII:C by the patient's plasma volume (13).
Vol.61,No. 3
FACTORVlllMONOCLONALCONCENTRATES
288
RESULTS Table
1 summarizes
the
results
of the TABLE
pharmacokinetic
study.
1
Pharmacokinetic parameters of monoclonal Factor VIII concentrates, according model-independent and compartmental analysis. Monoclate P
Dose
(IU) 26.2+2.1 Peak (IU/dL) 56.9T17.2 Time of peak (hr) 0.2920.30 Model-independent parameters: Clearance 4.9+3.1 (ml/h/kg) Mean residence time (h) 17.6T6.4 Half-life (h) 12.2T4.4 Vd Area 72.5722.9 (ml/kg) In Vivo Recovery (%) 100.8'32.4 Compartmental parameters:* biphasic decay curves 7 alpha half-life (h) 1.25+0.96 beta half-life (h) 14.73z7.13
Monoclate HT
Hemofil M
p-value by Friedman's two-way ANOVA
30.0+5.8 53.459.0 0.2050.17
28.8+4.8 53.8513.1 0.22+0.17
0.25 0.50 0.40
5.0+1.6 15.7T4.7 10.9T3.2 75.9712.5 82.7x10.0
5.1+2.5 15.2T4.9 10.573.4 74.4T24.6 87.1T23.4 -
0.30 0.49 0.49 0.49 0.15
6 1.83+2.27 11.4523.46
8 0.92+0.66 11.7514.46
0.25 0.35
*Reported only for curves showing evidence of biphasic decay.
Friedman's two-way analysis of variance showed no significant differences in the model-independent and compartmental pharmacokinetic parameters of the three monoclonal concentrates. The percentage of curves showing evidence of biphasic decay was 60% for Monoclate HT, 70% for Monoclate P, and 80% for Hemofil M. Monoclate P showed the highest in vivo recovery, the lowest clearance and the longest mean residence time (and half-life). In addition, despite the fact that the average infused dose of Monoelate P was slightly lower than that of Monoclate and Hemofil M, the peak values observed after Monoclate P were on average higher. While these data seem to indicate that Monoclate P has a slightly better pharmacokinetic profile, none of the differences achieved statistical significance. the pharmacokinetic parameters determinated We also compared for the three monoclonal concentrates with those previously obtained for intermediate-purity concentrates. In 1988, Messori et al. (10) reported the following values (mean+SD) calculated from a series of 87 single-dose pharmacokinetic curves: clearance (h) = 11.00+4.9; Vd-area (ml/h/kg) = 3.85z1.94; half-life (ml/kg) = 58.20+21.3. The intermediate-purity products included in that evaluation were Kryobulin (N=39) and Kryobulin TIM3 (N=17) (Immuno, Vienna, Austria), Koate HT (N=18) (Cutter, Berkeley, Ga), and Hemofil (N=13) (Hyland, Glendale, Ca). The Comparison of these data with those reported in Table 1 indicates that the pharmacokinetic characteristics of the monoclonal concentraHowever, tes are similar to those of conventional concentrates.
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FACTOR VIII MONOCLONAL CONCENTRATES
289
all monoclonal concentrates seem to have a slightly higher clearance and a larger Vd-area than traditional factor VIII concentrates. In addition, Monoclate P shows a somewhat longer half-life (and MRT) in comparison with the other (monoclonal and intermediate-purity) products. DISCUSSION The three monoclonal concentrates evaluated in this study diffor Factor VIII purification fer substantially in the procedures and virus inactivation. In addition, although their specific activity with respect to the content of total protein, fibrinogen or immunoglobulins is similar, their content in von Willebrand Factor Antigen (vWFAg) differs greatly inasmuch the vWFAg/Factor VIII:C ratio is 0.02 in Hemofil M and around 0.10 in Monoclate HT (6). Since vWFAg is known to play a key role in Factor VIII:C stabilization both in vivo and in vitro, the differences in vWFAg content might result in differences in pharmacokinetic behavior of the concentrates. This study, however, showed no clear difference in the pharmacokinetics of Monoclate HT, Monoclate P, and Hemofil M, thus indicating that the different fractionation methods, virucidal methods and contents of vWFAg of the concentrates do not affect the rate of Factor VIII:C disappearance from plasma. Similar preliminary results have been recently obtained in another cross-over study for two pasteurized concentrates, differing widely in their vWFAg content (14,15). Finally, the trend towards a faster Clearance and larger Vdarea for monoclonal products, compared with intermediate-purity concentrates deserves some comments. While on the one hand this finding suggests that monoclonal concentrates have a larger extra-vascular diffusion, on the other it remains at present unknown if the diffusion of Factor VIII:C in the extra-vascular space is beneficial in terms of hemostatic efficacy.
REFERENCES 1. Antihemophilic Factor (Human), Method M, Monoclonal purified. Baxter Health Care Corporation, Hyland Division, Glendale, CA, USA, 1988. 2. HOROWITZ, B., WIEBE, M.E, LIPPIN, A., STRYKER, M.H. Inactivation of viruses in labile blood derivatives. I-Disruption of lipid-enveloped viruses by tri(n-butyl)phosphate detergent combinations. Transfusion 25,516-522, 1985.
3. ZIMMERMAN, T.S. Purification of Factor VIII by monoclonal Antibody Affinity Chromatography. Semin. Hemat., 25, Suppl. 1, 25-26, 1988. 4. SCHREIBER, A.B. The preclinical characterization of Monoelate Factor VIII:C antihemophilic factor (Human). Semin. Hemat., 25, Suppl. 1, 27-32, 1988.
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Vol. 61, No. 3
5. HRINDA, M.E., FELDMAN, F., SCHREIBER, A.L. Preclinical characterization of a new pasteurized monoclonal antibody purified Factor VIIIC. Semin. Hemat., 27, Suppl. 2, 19-24, 1990.
6. MORFINI, M., RAFANELLI, D., FILIMBERTI, E., CINOTTI, S., PIAZZA, E., LONGO, G. AND ROSS1 FERRINI, P. Protein content and Factor VIII complex in untreated, treated and monoclonal concentrates. Thromb. Res., 56, 169-178, 1989. 7. LANGDELL, R.D, WAGNER, R.H, BRINKHOUS, K.M. Effect of antihaemophilic factor on one-stage clotting test. J Lab Clin Med 1953;41:637-41. 8. WILLIAMS, K.N., DAVIDSON, J.M.F., INGRAM, G.I.C. A computer program for the analysis of parallel-lines bioassay of clotting factors. Br. J. Haematol., 31, 13-23, 1975.
9. MESSORI, A, LONGO, G., MATUCCI, M., MORFINI, M., ROSS1 FERRINI, P. Clinical pharmacokinetics of Factor VIII in patients with classic hemophilia. Clin. Pharmacokinet., 13,365-380, 1987. 10. MESSORI, A, LONGO, G., MORFINI, M., CINOTTI, S., FILIMBERTI, E ., GIUSTARINI, G., ROSS1 FERRINI. P. Multivariate analysis of factors governing the pharmacokinetics of exogenous Factor VIII in hemophiliacs. Eur. J. Clin. Pharmacol., 35, 663-668, 1988. 11. MATUCCI, M., MESSORI, A., DONATI-CORI, G., LONGO, G., VANNINI, S., MORFINI, M., TENDI, E., ROSS1 FERRINI, P. Kinetic evaluation of four Factor VIII concentrates by model-independent methods. Stand. J. Haematol. 34, 22-28, 1985. 12. LONGO, G., MATUCCI, M., MESSORI, A., MORFINI, M., ROSS1 FERRINI. P.. Pharmacokinetics of a new heat-treated concentrate of Factor VIII estimated by model-independent methods. Thromb. Res., 42, 471-476, 1986. 13. MORFINI, M., MESSORI, A., LONGO, G., CINOTTI, S., MATUCCI, M ROSS1 FERRINI, P. Half-life and in vivo recovery of heated Fa&or VIII Lancet, II, 571-572, 1986.
14. SCHIMPF, K., REIS, T. Comparison of recovery and half-life of a new factor VIII high-purity concentrate (FVIII C HS) with a factor VIII HS (Haemate P). Ricerca Clin. Lab., 16, 231, 1986. 15. BLOMBACK, M., CINOTTI, S., LONGO, G., MESSORI, A., MORFINI, SCHIMPF, K. Pharmacokinetics of two pasteurized factor VIII M study on the reproducibility of co&entrates: a multi-center parameters using different assay methods. XIX International Congress of World Federation of Hemophilia, Washington D.C., August 14-19, 1990.
