Manufacturing

Genzyme has extensive experience in researching, developing, and manufacturing treatments for lysosomal storage disorders. Fabrazyme^® (agalsidase beta) manufacturing occurs exclusively at Genzyme production facilities. The highly complex, multistep process is established, scalable, and rigorously controlled to help ensure consistency and reliability.

Fabrazyme is produced by state-of-the-art molecular biologic techniques. Genzyme has over 10 years experience with the methodology, which is similar to that used to produce numerous other therapeutic proteins.

Early studies of enzyme replacement in the 1970s and 1980s using α-GAL purified from human tissues were promising,^[1] but practical application was impossible because of the difficulty of obtaining enough purified human enzyme. The advent of genetic engineering and recombinant human DNA technology allowed for production of substantial quantities of therapeutic proteins such as human α-GAL.

^{Well-characterized host cell to help ensure safety}

Fabrazyme production begins with genetic modification of a host cell to produce α-GAL from human DNA. The CHO (Chinese hamster ovary) cell line was chosen for its well-characterized track record in the manufacturing of biopharmaceuticals. In fact, nearly 1 million patients received therapeutic proteins produced by CHO cells during the past year ^[2]with no evidence of viral transmission. Being of non-human origin, CHO cells are less vulnerable to contamination by human viruses than cells of human origin. ^[3]

^{Protein manufactured using highly regulated techniques to help ensure reproducibility}

• The human α-GAL gene is isolated, spliced into a bacterial plasmid, and then inserted into the CHO host cell, which serves as a hospitable environment to manufacture the protein.
• In a bioreactor under carefully controlled conditions, the cells grow in a liquid medium of about 50 different nutrients such as sugar, amino acids, and salts.
• Throughout the production process the cells remain continuously in suspension, using up to 2,500 liters of medium per day.
• Liquid is removed daily and the enzyme is drawn off and collected for purification.

^{Multistep process to help ensure purity of protein}

• The enzyme goes through a multistep purification process, including chromatography and nanofiltration, capable of removing virus particles.
• To help ensure the product meets worldwide regulatory authority standards and specifications, rigorous testing takes place during every stage of the manufacturing process.

^{Product is filled, labeled, tested, and prepared for shipping}

• The purified α-GAL is stabilized with excipients and undergoes double-sterile filtration before it is distributed into vials under aseptic conditions.
• More than 20,000 vials are filled in a 6-hour period.
• The vials are lyophilized (freeze-dried to remove oxygen and water) to enhance stability and storage.
• After lyophilization, vials are ready for quality-control testing.

^{Rigorous testing to help ensure consistent quality}

• Each lot of Fabrazyme undergoes an extensive series of quality control tests before being released to confirm consistent quality.

Indications and Usage Fabrazyme (agalsidase beta) is indicated for use in patients with Fabry disease. Fabrazyme reduces globotriaosylceramide (GL-3) deposition in capillary endothelium of the kidney and certain other cell types. The reduction of GL-3 inclusions suggests that Fabrazyme may ameliorate disease expression; however, the relationship of GL-3 inclusion reduction to specific clinical manifestations of Fabry disease has not been established. Important Safety Information Life-threatening anaphylactic and severe allergic reactions have been observed in patients during Fabrazyme infusions. In clinical trials and postmarketing safety experience, approximately 1% of patients developed anaphylactic or severe allergic reactions during Fabrazyme infusions. Reactions have included localized angioedema (including swelling of the face, mouth, and throat), bronchospasm, hypotension, generalized urticaria, dysphagia, rash, dyspnea, flushing, chest discomfort, pruritus, and nasal congestion. Interventions have included cardiopulmonary resuscitation, oxygen supplementation, IV fluids, hospitalization, and treatment with inhaled beta-adrenergic agonists, antihistamines, epinephrine, and IV corticosteroids. If severe allergic or anaphylactic reactions occur, immediately discontinue administration of Fabrazyme and provide necessary emergency treatment. Because of the potential for severe allergic reactions, appropriate medical support measures should be readily available when Fabrazyme is administered. In patients experiencing infusion reactions, pretreatment with an antipyretic and antihistamine is recommended. Infusion reactions occurred in some patients after receiving pretreatment with antipyretics, antihistamines, and oral steroids. If an infusion reaction occurs, decreasing the infusion rate, temporarily stopping the infusion, and/or administrating additional antipyretics, antihistamines, and/or steroids may ameliorate the symptoms. If severe infusion reactions occur, immediate discontinuation of the administration of Fabrazyme should be considered, and appropriate medical treatment should be initiated. Severe reactions are generally managed with administration of antihistamines, corticosteroids, intravenous fluids, and/or oxygen when clinically indicated. Because of the potential for severe infusion reactions, appropriate medical support measures should be readily available when Fabrazyme is administered. Re-administration of Fabrazyme to patients who have previously experienced severe or serious allergic reactions to Fabrazyme should be done only after careful consideration of the risks and benefits of continued treatment, and only under the direct supervision of qualified personnel and with appropriate medical support measures readily available. The most common adverse reactions reported are infusion reactions, some of which were severe. Infusion reactions occurred in approximately 50-55% of patients during Fabrazyme administration in clinical trials. Serious and/or frequently occurring (≥ 5% incidence) related adverse reactions consisted of one or more of the following: chills, fever, feeling hot or cold, dyspnea, nausea, flushing, headache, vomiting, paresthesia, fatigue, pruritus, pain in extremity, hypertension, chest pain, throat tightness, abdominal pain, dizziness, tachycardia, nasal congestion, diarrhea, edema peripheral, myalgia, back pain, pallor, bradycardia, urticaria, hypotension, face edema, rash, and somnolence. Patients with advanced Fabry disease may have compromised cardiac function, which may predispose them to a higher risk of severe complications from infusion reactions. Patients with compromised cardiac function should be monitored closely if the decision is made to administer Fabrazyme. Other serious adverse events reported in clinical studies included stroke, pain, ataxia, bradycardia, cardiac arrhythmia, cardiac arrest, decreased cardiac output, vertigo, hypoacousia, and nephrotic syndrome. These adverse events also occur as manifestations of Fabry disease; an alteration in frequency or severity cannot be determined from the small numbers of patients studied. Severe and serious infusion related reactions have been reported in postmarketing experience, some of which were life threatening including anaphylactic shock. In addition to the above adverse reactions, the following have been reported during postmarketing use of Fabrazyme: arthralgia, asthenia, erythema, hyperhidrosis, infusion site reaction, lacrimation increased, leukocytoclastic vasculitis, lymphadenopathy, hypoesthesia, oral hypoesthesia, palpitations, rhinorrhea, oxygen saturation decreased and hypoxia. Adverse reactions (regardless of relationship) resulting in death reported in the postmarketing setting with Fabrazyme treatment included cardiorespiratory arrest, respiratory failure, cardiac failure, sepsis, cerebrovascular accident, myocardial infarction, renal failure, and pneumonia. Some of these reactions were reported in Fabry disease patients with significant underlying disease. The safety and efficacy in patients younger than 8 years of age have not been evaluated. Most patients who develop IgG antibodies do so within the first three months of exposure.  IgG seroconversion in pediatric patients was associated with prolonged half-life of Fabrazyme, a phenomenon rarely observed in adult patients. In clinical trials, a few patients developed IgE or skin test reactivity specific to Fabrazyme. Physicians should consider testing for IgE in patients who experienced suspected allergic reactions and consider the risks and benefits of continued treatment in patients with anti-Fabrazyme IgE antibodies. Fabrazyme is available by prescription only. Side effects should be reported promptly to Genzyme Medical Information at 800-745-4447, option 2. To learn more, please see the full Prescribing Information (PDF) or contact Genzyme at 1-800-745-4447.

^References

1. Desnick RJ, Dean KJ, Grabowski G, Bishop DF, Sweely CC. Enzyme therapy in Fabry disease: differential in vivo plasma clearance and metabolic effectiveness of plasma and splenic α-galactosidase A isozymes. Proc Natl Acad Sci U S A 1979; 76:5326-30.

2. Data on file. Genzyme Corporation.

3. Wiebe ME, Becker F, Lazar R, May L, Casto B, Semense M, Fautz C, Garnick R, Miller C, Masover G, Bergmann D, Lubiniecki AS. A multifaceted approach to assure that recombinant tPA is free of adventitious virus. In: Advances in Animal Cell Biology and Technology for Bioprocesses. Great Britain, 1989; 68-71.