Status: approved; marketed

Organizations involved:

Baxter Hyland Immuno – Manuf.; R&D, Tech.; USA Mark.

Baxter AG – Manuf. other

University of Connecticut – Tech.

Baxter Healthcare Corp. – Intl. mark.; Parent

CSL Behring AG – Patent dispute

CSL Ltd. – Parent

Sanofi Aventis S.A. – Patent dispute

Aventis Pharma AG – Patent dispute; Former

New York Blood Center, Inc. – Tech.

Cross ref.: See the entry above for Recombinate (#147), an earlier recombinant Factor VIII product from Baxter, containing the same recombinant Factor VIII. See the Factor VIII Products entry (#715) in the Blood Products, Human section.

Description: Advate or Antihemophilic Factor (Recombinant), Plasma/Albumin Free Method is a lyophilized (freeze-dried) formulation of recombinant full-length Factor VIII glycoprotein expressed by a Chinese ovary hamster (CHO) cell line (the same as used for manufacture of Recombinate, Baxter’s original recombinant Factor VIII product), but without direct use of animal proteins, with immunoaffinity purification using matrix-bound Factor VIII monoclonal antibody, and with addition of a solvent-detergent viral inactivation step. The recombinant Factor VIII in Advate (and Recombinate) has the same primary sequence (2,332 amino acids) and biological effects as Antihemophilic Factor (Human) or Factor VIII purified from blood plasma, and structurally has a combination of heterogenous heavy and light chains similar to native human Factor VIII. The recombinant Factor VIII amino acid sequence has a molecular weight of 280 kDa, and over 300 kDa after glycosylation, with post-translational changes (glycosylation, folding, etc.) similar to human plasma-derived Factor VIII. The recombinant Factor VIII is a heterodimer composed of a 80 kDa light chain, derived from the C-terminus of Factor VIII, bound to a heavy chain with molecular weight between 90-210 kDa, including the 90 kDa N-terminal sequence and varying amounts of the B-domain (which is not required for activity), where 19 of 25 potential N-linked glycosylation sites are located. The Factor VIII also contains 10-12 O-linked glycan (glycosylation sites), all or most residing in the B-domain. Advate has been shown to be comparable to Recombinate with respect to its biochemical and physicochemical properties, as well as its non-clinical in vivo pharmacology and toxicology.

Unlike all previously approved recombinant Factor VIII products, this product is manufactured entirely without the addition of any human or animal proteins, including Albumin (Human) as a stabilizer, during cell culture, purification and final formulation (theoretically, eliminating the risk of viral and prion contamination associated with animal-derived proteins).

Advate is formulated as a sterile, non-pyrogenic, white to off-white powder for intravenous injection in single-dose vials that contain nominally 250, 500, 1000, 1,500 or 3,000 International Units (IU) per vial. Advate is packaged with 5 mL of Sterile Water for Injection, a double-ended needle, a filter needle, and infusion set/blood collection set, 10 mL. When reconstituted with 5 mL of Sterile Water for Injection, the 250 IU/vial, 500 IU/vial, 1,000 IU/vial and 1,500 IU/vial nominal potencies have concentrations of approximately 50 IU/mL, 100 IU/mL, 200 IU/mL, and 300 IU/mL, respectively. After reconstitution, each of the potencies contains approximately 10 mM histidine (buffer), 10 mM Tris (buffer), 90 mM sodium chloride, 0.010% (w/v) polysorbate 80 (Tween 80; surfactant), 3.2% (w/v) mannitol (bulking agent), 0.8% (w/v) trehalose (disacharide stabilizer), 0.08 mg/mL reduced glutathione (reducing agent), and 1.7 mM calcium chloride. The super-high potency 1,500 IU per vial has a smaller infusion volume (5 mL diluent), which means shorter infusion times for patients. The specific activity of Factor VIII in Advate is 4,000 to 10,000 IU/mg protein. The final product contains trace amounts of recombinant von Willebrand’s Factor (not enough to be clinically relevant effect in patients with von Willebrand’s disease).

Advate is stored at 2°-8°C (36-46°F; refrigerated) and may be stored at room temperature for a period of up to 6 months . The dating period for Advate when stored at 2-8°C is 18 months from the date of manufacture, defined as the date of final sterile filtration of the formulated drug product. The expiration date for the packaged product, Advate and Sterile Water for Injection, is the shortest expiration date of either component.

Each vial of Advate is labeled with its antihemophilic factor (Factor VIII:C) activity expressed in IU per vial. Biological potency is determined by an in vitro assay, which employs a Factor VIII concentrate standard that is referenced to a World Health Organization (WHO) International Standard for Factor VIII:C concentrates.

Advate contains trace amounts of mouse immunoglobulin G (IgG; maximum of 0.1 ng/IU), residual from immunoaffinity purification, and hamster (CHO) proteins (maximum of 1.5 ng/IU), residual from culture of transformed CHO cells.

Nomenclature: Antihemophilic Factor (Recombinant), Plasma/Albumin Free Method [FDA]; octocog alfa [INN]; Advate [TR]; Octocog Alfa Recombinant Coagulation Factor VIII [EU]; Factor VIII, recombinant [SY]; AHF-PFM [SY]; NDC 0944-2940-01, NDC 0944-2940-02, NDC 0944-2940-03, NDC 0944-2940-04 [NDC]

Companies.: Advate was developed and is manufactured and marketed worldwide by Baxter Hyland Immuno (CBER/FDA est. no. 0140). Clinical supplies used in earlier trials were manufactured at Baxter facilities in Orth, Austria. Recombinant Factor VIII is commercially manufactured by Baxter in dedicated facilities (Suites A and B) within a state-of-the art, 110,000 sq ft., $130+ million facility in Neuchatel, Switzerland. Baxter claims this facility has the capacity to ensure sufficient supplies based on current and anticipated patient needs. Formulation, lyophilization and finishing are performed by Baxter AG, Vienna, Austria. Labelling and packaging are performed at Baxter S.A., Lsssines, France. Dedicated equipment is used throughout product manufacturing.

Baxter claims Advate to be “the only [recombinant Factor VIII] supplier which has consistently increased the supply of Factor VIII year after year without interruption.”

Manufacture: The CHO cell line, clone GD8/6, employed in the production of Advate is derived from that used in the manufacture of Recombinate. To generate clone GD8/6, an expression plasmid containing Factor VIII cDNA was co-transfected into dihydrofolate reductase (DHFR)-deficient CHO cells (DUKX-B11), along with a plasmid expressing a DHFR-selectable marker to create cell line 10A1. Methotrexate was used to amplify and select for increased Factor VIII expression. For co-expression of human von Willebrand’s factor (vWF), which bind and stabilizes the Factor VIII during processing, a plasmid containing vWF cDNA and a selectable adenosine deaminase (ADA) marker was introduced into the 10A1 cell line by protoplast fusion. Adenosine and deoxycoformycin (dCF) were used to select for expression of vWF. Based on high levels of both Factor VIII and vWF expression, a single clonal cell line (10A1C6) was selected, adapted for plasma- and protein-free culture media, and used to create the Master Cell Bank 9710 (MCB 9710) production cell line. Studies indicate each cell contains ~25-100 copies of the Factor VIII gene and a few copies of the vWF gene, with these stable for at least 78 generations (beyond the production limit of 65 generations). A classic, two-tiered cell bank system (MCB and Working Cell Bank/WCB) is maintained at Baxter facilities in Hayward, CA, with WCB shipped by air to Switzerland deep frozen (<-90˚C) as needed.

The CHO cells are cultured by a continuous (chemostat) perfusion process, unlike Factor VIII:vWF for Recombinate which is manufactured by a batch-fed process. One or two WCB vials are inoculated and expanded in roller bottle culture. This is further expanded in a series of three bioreactor steps, with the last being a 2,500 L bioreactor, the contents of which are used to also inoculate a second 2,500 bioreactor, both of which are used for production. Continuous culture in the 2,500 L bioreactors is then maintained for up to 65 generations from the thawing of the WCB vials, involving 60 days of continuous culture after the expansion phase. As the cells grow exponentially, recombinant Factor VIII and vWF are secreted into the medium. The recombinant Factor VIII and vWF are co-expressed by the transformed CHO cells, with the vWF non-covalently binding to Factor VIII to form Factor VIII:vWF complex or Factor VIII:C (much the same as the native human form of this complex), with bound vWF stabilizing Factor VIII during processing and storage. The cell line expresses both recombinant human Factor VIII and vWF from coding regions identical to those used for Recombinate. There are no known changes in the promoter region of these sequences. The cell line for manufacture of Advate has been adapted for a culture medium that does not contain additives of human or animal origin. Physiochemical analyses have shown that the recombinant Factor VIII molecule in commercial-scale Advate is comparable to pilot-scale product (Manufactured in a different facility) and Factor VIII in Recombinate.

The Factor VIII made by the CHO cells is expressed into the cell culture medium and purified using a series of chromatography columns, including an immunoaffinity purification. The Factor VIII is purified and the vWF is removed using an immunoaffinity chromatography column with a matrix-bound murine (mouse) F8.1 monoclonal antibody with affinity for an epitope on the 90 Da heavy chain of Factor VIII, which can be further localized to the 43 kDa fragment after digestion of recombinant Factor VIII. The antibodies used for purification are produced in a plasma and albumin-free culture by Baxter in Hayward, CA, apparently from the GI-F8/1.5.6 (ATCC HB 11552) cell line developed by Genetics Inst./Wyeth. The same monoclonal antibodies are used for purification of Factor VIII for Recombinate and plasma-derived Hemophil. Purification of the monoclonal antibody includes Protein A affinity chromatography, with validated removal of Protein A.

A production campaign/lot (as described in the European Product Assesment Report) consists of bulk material (drug substance) derived from the same WCB vial(s), and consists of about 20 production batches. A batch is defined as that resulting from one elution step of the immunoaffinity column. Usually, three cell culture harvests are loaded and purified to produce one batch. A harvest is defined at the cell suspension collected from the 2,500 L bioreactors in a 24-hour period (1,250 L/bioreactor/day). One batch has a volume of 700-1,400 mL, a minumum potency of 1,250 IU/mL, with a specific activity of 4,000-10,000 IU/mL protein.

Cell culture harvest is purified much the same as for Recombinate. Modifications of this process include the addition of a solvent-detergent viral inactivation step using 1% octoxynol (Triton X-100) and 0.3% polysorbate 80 (Tween 80) as the surfactants/detergents and tri-n-butyl phosphate (TNBP) as the solvent component. The main steps in purification are immunoaffinity chromatography; cation exchange chromatography; solvent-detergent viral inactivation; and anion exchange chromatography, with eluate (drug substance) frozen at -80˚C for storage. Advate is later stabilized in a unique formulation of sugars, salts, and amino acids, without use of human serum albumin as used in other recombinant Factor VIII concentrates, e.g., Recombinate.

Cell culture harvest is tested for mycoplasma, sterility, and adventitious agents at the end of each manufacturing campaign. Drug product testing includes determinations of potency, protein concentration, specific activity, sterility, appearance (before reconstitution; and coloration and clarity after reconstitution), residual moisture, pH, and excipient levels. Final formulated product testing includes potency, specific activity, aggregates, solubility, identity and purity, endotoxins, and glutathione (total and reduced). Potency is tested using the chromogenic method (and also the older one-stage clotting method), with the in-house standard calibrated against the Mega 1 and WHO 6 international standard for Factor VIII:C.

The Master and Work Cell Banks (MCB and WCB) have been characterized and found to be stable in genotype and free of any detectable bacterial, or fungal contamination. No adventitious virus was detected from a conventional testing program prior to approval. The manufacturing process for has been validated for consistency, robustness and for removal of impurities. Validation studies have been accepted in lieu of lot-by-lot testing of drug substance and drug product to establish the removal of certain defined contaminants. Various steps in the purification process, e.g., solvent-detergent treatment and column chromatography, were validated for their ability to remove a variety of model viruses that may not have been detected in the production cells. However, the chromatography steps contribute relatively little to virus removal, particularly non-enveloped viruses not affected by the solvent-detergent process. Upon approval, no testing or purification validation had been carried out for bovine spongiform encephalopathy (BSE). However, no animal or human components are used in manufacturing process, with amino acids not derived from animal sources, so the possibility of introducing BSE into the manufacturing process is considered to be negligible. Production of commercial lots of Advate began in Dec. 2000.

FDA class: Biologic BLA

CBER class: Blood And Blood Derivatives

Approvals: Date = 20030725; BLA (STN BL 125063/0), first approval

Date = 20060500; BLA supplement; Indication = new 2,000 IU vial

Date = 20060506; BLA supplement; Indication = new 2000 IU Ultra-High dosage vial

Date = 20070711; BLA supplement; Indication = new 3000 IU (5 mL) dosage strength [launched in Aug.]

Indications: [full text of the "INDICATIONS AND USAGE” section of product insert/labeling; 7/2/2006]:

ADVATE is indicated in Hemophilia A (classical hemophilia) for the prevention and control of bleeding episodes. ADVATE is also indicated in the perioperative management of patients with Hemophilia A. ADVATE can be of therapeutic value in patients with Factor VIII inhibitors not exceeding 10 Bethesda Units (BU) per mL. However, in patients with a known or suspected inhibitor to Factor VIII, the plasma Factor VIII level should be monitored frequently and the dose of ADVATE should be adjusted accordingly.

ADVATE is not indicated for the treatment of von Willebrand’s disease.

Status: Baxter filed a BLA on June 27, 2002. Approval was granted on July 25, 2003 (approval time = ~1.08 years). This was the first approval of Advate in any country. Advate was launched in the U.S. in late August, 2003, with U.S. availability announced in a press release on Sept. 12, 2003.

Advate is exempt from CBER/FDA lot release inspection requirements.

A Marketing Authorization Application (MAA) for European Union (EU) approval was filed in Sept. 2002, with EU approval granted on March 2, 2004. Approval in Switzerland was granted on Feb. 18, 2004. In Dec. 2004, the EU granted supplemental approval for use in children under the age of 6 in the treatment and prophylaxis of bleeding in patients with haemophilia A, whether previously treated with Factor VIII or not; effectively making Advate available to pediatric hemophilia A patients.

In May 2006, FDA approved a new 2,000 IU Ultra-High dosage vial of Advate, making it easier for people requiring higher doses to administer Advate by reducing both the infusion volume of drug solution and the storage space. A new 3,000 IU vial was approved in July 2007.

On Aug. 2, 2006, Baxter received approval for Advate in Canada for the prevention and control of bleeding episodes in people with hemophilia A and for perioperative management of patients with hemophilia A.

In Oct. 2006, Baxter launched BAXJECT II, a needle-less transfer device designed to make the reconstitution and mixing of hemophilia factor therapies easier, faster and safer (as compared to the original BAXJECT and needles). Unlike other devices, BAXJECT II is compatible with existing injection ports and butterfly sets. BAXJECT eliminates the need for needles to mix Factor VIII. BAXJECT II can be used with ADVATE and all other Baxter Factor VIII therapies.

In Nov. 2006, Baxter received approval for Advate in Japan as a replacement therapy indicated for blood coagulation and to reduce the tendency to bleed for people with hemophilia A. At the time, Advate was also approved in the U.S., Canada, Australia and 28 countries in Europe.

As of July 2007, Advate was approved in the approved for use in the U.S., Canada, Australia, Japan and EU.

Tech. transfer: See the entry above for Recombinate (#147), an earlier recombinant Factor VIII product from Baxter, containing the same recombinant Factor VIII.

In April 2003, Aventis Behring, now CSL Behring (Manufacturer and marketer of other Factor VIII products), filed suit against Baxter alleging infringement of its patents covering manufacture of recombinant Factor VIII without use of Albumin (Human) as a stabilizer. These includes U.S. 5,565,427, and other “Freudenberg” patents assigned to Behringwerke AG (later Aventis Pharma; became Sanofi Aventis S.A. in late 2004), with certain rights/co-assignment to CSL Behring, concerning formulations to stabilize Factor VIII. Patent claims include stabilization using amino acids, non-ionic detergents, and carbohydrates (e.g., sucrose). The detergent, polysorbate 20 or polysorbate 80, is described as being present in amounts of between 0.001-0.5% (v/v), while arginine and glycine are present in amounts of between 0.01-1 mol/l. Sucrose is present in amounts of between 0.1 and 10%. Example 2 of this patent asserts that a solution of 1% sucrose, 0.14 M arginine, 0.1 M sodium chloride and solution of 1% sucrose, 0.4 M glycine, 0.14 M arginine, 0.1 M sodium chloride, and 0.05% Tween 80 both exhibited stability. With the Dec. 2003 acquisition of Aventis Behring by CSL, forming ZLB Behring (now CSL Behring), CSL reported that ZLB and Aventis Pharma (now Sanofi Aventis) would continue to jointly prosecute these patents.

In July 2003, Abbott and the University of Connecticut jointly received U.S. 6,586,573, “Albumin-free Factor VIII formulations.” calculated to expire Feb 22, 2019. Claim no. 1 covers Factor VIII formulations containing 4-10% of a bulking agent (mannitol, glycine and/or alanine; 1-4% of a stabilizing agent (sucrose, trehalose, raffinose, and arginine); a calcium salt; 150-300 mM sodium chloride; a buffering agent; and an antioxidant (e.g., glutathione). Other claims include specific lyophilization methods.

Solvent detergent viral inactivation technology was developed by and nonexclusively licensed from the New York Blood Center. For example, see U.S. patent 4,820,805. See the entry for Pooled Plasma, Solvent Detergent Treated (SD Plasma) for further information about solvent detergent viral inactivation, used primarily for inactivation of membrane-coated viruses.

Referring to biogeneric and follow-on products, Baxter reports, “various U.S. patents for Advate run through the end of the decade so the company has enough time to develop a longer-lasting version that would allow the company to maintain market share before a cheaper generic would emerge as a threat.”

Trials: Pivotal Phase II and III clinical trials (using product manufactured at Orth, Austria) evaluated the safety, immunogenicity and efficacy of Advate, including in comparison with Recombinate (earlier formulation of the same recombinant protein; see related entry above) in the treatment and prevention of bleeding in previously treated hemophilia patients in a variety of clinical settings. A global, multicenter, randomized double-blind, cross-over study showed that Advate and Recombinate are bioequivalent; should exhibit comparable hemostatic efficacy in the management of hemophilia A; and Advate was effective in controlling bleeding episodes. Pharmacokinetic studies showed Advate clinical supplies manufactured at Orth, Austria, facilities were bioequivalent to product manufactured in commercial scale at Neuchatel, Switzerland, facilities.

Approximately 2% of subjects in the clinical trials of Advate had a rise in antibodies to either CHO cell or murine proteins, but there were no cases of clinical allergy.

A global Post Authorization Safety Surveillance was put in place immediately after launch of Advant.

Medical: For treatment of hemorrhaging in hemophilia A patients, Advate is administered by infusion, with additional dosing every 8-24 hours as needed to control bleeding. In preparation for surgical procedures, Advate is given as a single bolus infusion, e.g., beginning within one hour of the start of a major surgical operation, with additional dosing every 8-24 hours as needed to control bleeding.

The expected in vivo peak increase in Factor VIII level expressed as IU/dL of plasma or percent of normal can be estimated by multiplying the dose per kg body weight (IU/ kg) by two. This calculation is based on the findings of several pharmacokinetic studies, including data from pharmacokinetic studies with Advate in 107 Phase II/III pivotal study subjects.

Market: The 2007 Average Wholesale Price (AWP) is $1.68/IU for all vial sizes (Red Book, 2007). AWPs were $1.47/IU in 2005. and $1.66/IU in 2004.

Medicare reimbursement is $1.29/IU for inpatient and home care, and $1.01/IU for outpatient care [from NHF].

Total worldwide Advate plus Recombinante sales were $2.058 billion in 2009, up 8% from 2008, with Advate increasingly dominating market share.

Total worldwide sales were about $1.5 billion and growing in 2008; $800 million in 2006; and 2004 sales were reported to be nearly $300 million. Total 2003 (partial year; launched only in the U.S. in August) sales in the U.S. have been reported to be ~$45 million. Advate’s initial sales (U.S. only) had been expected to be about $100 million. Baxter had previously projected peak worldwide sales to reach $1 billion by 2005.

In March 2005, one year after European Union approval, Baxter reported, Advate had been launched in 14 European countries, and in the past three months, Advate accounted for the majority of Baxter’s total recombinant Factor VIII units sold in Europe.

In Jan. 2006, Baxter announced that accumulated sales of Advate had surpassed one billion activity units, in large part because of rapid adoption in the U.S. and Europe since the therapy’s launch in 2003 and 2004, respectively. “The new sales figures establish Advate as the number one selling therapy in Baxter’s hemophilia franchise, surpassing Recombinate [Antihemophilic Factor (Recombinant)] as the company’s leading recombinant FVIII therapy. The rapid adoption of Advate indicates that pathogen risk is still a primary concern to the hemophilia community.” Also, data from Baxter’s pharmacovigilance program reaffirmed Advate’s safety profile, including a low reported incidence of inhibitor development in previously treated patients. Advate remains the world’s first and only recombinant factor VIII therapy processed without the addition of animal or human blood components.

R&D: In Oct. 2005, Baxter concluded collaborative R&D agreements with both Nektar Therapeutics Inc., with particular expertise in pegylatation, and Lipoxen Technologies to develop longer-acting blood-clotting drugs, with the goal of decreasing the time between injections. This apparently involves polymeric-modified forms of Factor VIII. Nektar is developing a formulation, presumably a pegylyated (polyethylene glycol polymer conjugate) form designed for use once weekly, with trials expected to start in 2010. Nektar will receive payments for manufacture of polyethylene glycol (PEG) reagents, and is eligible for milestones and royalties. Baxter will handle clinical development, manufacturing and marketing. Lipoxen Technologies will use its PolyXen technology, involving attachment of the natural polymer polysialic acid (PSA), to prolong the active life and improve the pharmacokinetics of Factor VIII. Being chemically identical to polysialic acid in the human body, bacterial polysialic acid is completely non-immunogenic, even when coupled to proteins.