DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Recombinate (Antihemophilic Factor) - Description and Clinical Pharmacology

 
 



Lyophilized Powder for Reconstitution for injection

 

Reconstitute with 10 mL of Sterile Water for Injection using Baxject II

DESCRIPTION

RECOMBINATE [Antihemophilic Factor (Recombinant)] is a glycoprotein synthesized by a genetically engineered Chinese Hamster Ovary (CHO) cell line. In culture, the CHO cell line secretes recombinant Factor VIII (rFVIII) into the cell culture medium. The rFVIII is purified from the culture medium utilizing a series of chromatography columns. A key step in the purification process is an immunoaffinity chromatography methodology in which a purification matrix, prepared by immobilization of a monoclonal antibody directed to Factor VIII, is utilized to selectively isolate the rFVIII in the medium. The synthesized rFVIII produced by the CHO cells has the same biological effects as human Factor VIII. Structurally the protein has a similar combination of heterogenous heavy and light chains as found in human Factor VIII.

RECOMBINATE is formulated as a sterile, nonpyrogenic, off-white to faint yellow, lyophilized powder preparation of concentrated recombinant Factor VIII for intravenous injection. RECOMBINATE is available in single-dose vials, which contain nominally 250, 500 and 1000 International Units per vial. When reconstituted with the appropriate volume of diluent, the product contains the following stabilizers in maximum amounts: For 10 mL reconstitution volume: 12.5 mg/mL Albumin (Human), 0.20 mg/mL calcium, 1.5 mg/mL polyethylene glycol (3350), 180 mEq/L sodium, 55 mM histidine, 1.5 µg/Factor VIII International Unit (IU) polysorbate-80. Recombinant Von Willebrand Factor (rVWF) is coexpressed with the rFVIII and helps to stabilize it. The final product contains not more than 2 ng rVWF/IU rFVIII, which will not have any clinically relevant effect in patients with von Willebrand’s disease. The product contains no preservative.

Manufacturing of RECOMBINATE is shared by Baxter Healthcare Corporation and Wyeth BioPharma. The recombinant Antihemophilic Factor Concentrate (For Further Manufacturing Use), is produced by Baxter Healthcare Corporation and Wyeth BioPharma (For Further Manufacturing Use) and subsequently formulated and packaged at Baxter Healthcare Corporation.

Each vial of RECOMBINATE is labeled with the Factor VIII activity expressed in IU per vial. Biological potency is determined by an in vitro assay which is referenced to the World Health Organization (WHO) International Standard for Factor VIII:C Concentrate.

CLINICAL PHARMACOLOGY

Factor VIII is the specific clotting factor deficient in patients with hemophilia A (classical hemophilia). Hemophilia A is a genetic bleeding disorder characterized by hemorrhages, which may occur spontaneously or after minor trauma. The administration of RECOMBINATE provides an increase in plasma levels of Factor VIII and can temporarily correct the coagulation defect in these patients. Pharmacokinetic studies on sixty-nine (69) patients revealed the circulating mean half-life for RECOMBINATE to be 14.6 ± 4.9 hours (n=67), which was not statistically significantly different from plasma-derived HEMOFIL M, [Antihemophilic Factor (Human), Method M, Monoclonal Purified]. The mean half-life of HEMOFIL M was 14.7 ± 5.1 hours (n=61). The actual baseline recovery observed with RECOMBINATE was 123.9 ± 47.7 IU/dL (n=23), which is significantly higher than the actual HEMOFIL M baseline recovery of 101.7 ± 31.6 IU/dL (n=61). However, the calculated ratio of actual to expected recovery with RECOMBINATE (121.2 ± 48.9%) is not different on average from HEMOFIL M (123.4 ± 16.4%).

The clinical study of  RECOMBINATE in previously treated patients (individuals with hemophilia A who had been treated with plasma derived Factor VIII) was based on observations made on a study group of 69 patients. These individuals received cumulative amounts of Factor VIII ranging from 20,914 to 1,383,063 IU over the 48 month study. Patients were given a total of 17,700 infusions totaling 28,090,769 IU RECOMBINATE.

These patients were successfully treated for bleeding episodes on a demand basis and also for the prevention of bleeds (prophylaxis). Spontaneous bleeding episodes successfully managed include hemarthroses, soft tissue and muscle bleeds. Management of hemostasis was also evaluated in surgeries. A total of 24 procedures on 13 patients were performed during this study. These included minor (e.g. tooth extraction) and major (e.g. bilateral osteotomies, thoracotomy and liver transplant) procedures. Hemostasis was maintained perioperatively and postoperatively with individualized Factor VIII replacement.

A study of RECOMBINATE in previously untreated patients was also performed as part of an ongoing study. The study group was comprised of seventy-nine (79)1 patients, of whom seventy-six (76) had received at least one infusion of RECOMBINATE. To date, this cohort has been given 12,209 infusions totaling over 11,277,043 IU of RECOMBINATE. Hemostasis was appropriately managed in spontaneous bleeding episodes, intracranial hemorrhage and surgical procedures.

CLINICAL STUDIES

Over the investigational period of the original safety and efficacy study of RECOMBINATE, none of the 69 subjects without an inhibitor at entry into the study, developed an inhibitor. In the previously untreated patient group there were 73 eligible subjects with Factor VIII levels less than or equal to 2% who received at least one RECOMBINATE treatment (median days 100, range 3-821) and who were tested for an inhibitor after treatment with RECOMBINATE. Of this group, 23 individuals (32%) developed a detectable inhibitor (median days on treatment at time of detection 10, range 3-69) and of these, 8 subjects (11%) showed a titer greater than 10 B.U.

-- advertisement -- The American Red Cross
 
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2015