Ig Therapy

Immune globulin (Ig) products, produced from human plasma, were first used in 1952 to treat immune deficiency. Intravenous immunoglobulin (IVIg) contains the pooled immunoglobulin G (IgG) from the plasma of at least 1,000 healthy blood donors. The entire array of variable (antigen-binding) regions of antibodies in normal serum is contained in IVIg. The large number of donors in the pool increases the number of individual antibody activities in the preparation, but also risks diluting any useful rare activity (Scheinfeld 2008). IVIg is treated with physical and chemical viral inactivating regimens, as well as nanofiltration, making these preparations remarkably free of transmissible infectious agents. However, because they are blood products from a large number of donors, the risk of transmitting infectious agents is always present, although it is rare (Lin 2009).

Human IVIg therapy has evolved over the last 60 years from replacement therapy in patients with primary antibody deficiency to a treatment for a wide variety of diseases. As a group, IVIg products are FDA-approved for anti-infective therapy such as in bone marrow transplant, immune globulin replacement such as in primary immune deficiency (PID) and chronic lymphocytic leukemia (CLL), anti-inflammatory therapy such as in Kawasaki Disease, immunomodulation therapy such as in idiopathic thrombocytopenic purpura, and immune-mediated neurological disorders such as chronic inflammatory demyelinating polyneuropathy (CIDP) (see Table 1). For additional comparative information on IVIg, SCIg, and intramuscular Ig, see the PDF Immunoglobulin Comparsion Chart. However, the use for IVIg is constantly expanding and there are currently over 50 off-label indications. As additional uses of IVIg develop, larger numbers of patients with a wider variety of medical conditions are exposed to this therapy. While all IVIg products may be similarly equivalent in their therapeutic effect and are used interchangeably by many physicians, there are product differences (in the final purification steps, IgA content, and excipients) that may be clinically important in some patients (Nicolay 2006).

Table 1: FDA Approved Ig Therapy and Approved Indications

Product Manufacturer Indication Route Dosing
Carimune® NF CSL Behring PIDD IV 0.4 to 0.8 g/kg every 3 to 4 weeks
Flebogamma® DIF (5%) Grifols ITP IV 0.4 g/kg over 2 to 5 consecutive weeks
Flebogamma® DIF (10%) Grifols PIDD IV 300 to 600 mg/kg every 3 to 4 weeks
Gammagard® S/D (10%) Baxter Healthcare PIDD IV 300 to 600 mg/kg every 3 to 4 weeks
CLL IV 400 mg/kg every 3 to 4 weeks
ITP IV 1 g/kg
Kawaski Disease IV Either a single 1 g/kg dose, or a dose of 400 mg/kg for 4 consecutive days within 7 days of the onset of fever
Gammagard® Liquid (10%) Baxter Healthcare PIDD IV 300 to 600 mg/kg every 3 to 4 weeks
Gammaplex® (10%) Bio Products PIDD IV 300 to 800 mg/kg every 3 to 4 weeks
Gamunex-C® (10%) Grifols PIDD SC 1.37 x IVIg dose in mg/kg/iv dose interval in weeks, weekly
PIDD IV 300 to 600 mg/kg every 3 to 4 weeks
ITP IV 2 g/kg
CIDP IV - Loading dose: 2g/kg.
- Maintenance dose: 1g/kg every 3 weeks
Hizentra™ (16%) CSL Behring PIDD SC Initial dose: 1.53 x IVIg dose (in grams)/number of weeks between IVIg doses
Octagam® (5%) Octapharma PIDD IV 300 to 600 mg/kg every 3 to 4 weeks
Privigen™ (10%) CSL Behring PIDD IV 200 to 600 mg/kg every 3 to 4 weeks
ITP IV 1g/kg daily for 2 consecutive days (2g/kg total)
Vivaglobin® (16%) CSL Behring PIDD SC 1.37 x IVIg dose (in grams)/number of weeks between IVIg doses, weekly

 

A 2009 industry report found that approximately 55 percent of IVIg was prescribed for non-FDA approved indications (IVIg 2009). Overall (approved and off-label use) approximately 38,500 kilograms of IVIg were administered to approximately 85,100 patients in the U.S., with an average administration of 453 grams per patient per year. Sixty percent of the patients (and 67 percent of total grams) were used to treat seven diseases: PID, chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain Barre Syndrome (GBS), BMT, immune thrombocytopenic purpura (ITP), CLL, and Kawasaki disease. A comprehensive list of IVIg use is displayed in Table 2. This further suggests there will be a likely increase of 16,500 kilograms of IVIg administered by 2015 or approximately 36,000 additional patients treated. If other indications such as Alzheimer's disease and multifocal motor neuropathy are approved for IVIg therapy then the additional number of IVIg patients in 2015 could be over 66,100.

Table 2: IVIg Usage by Medical Specialty in 2009

Medical Specialty Patients Percent Kilograms Percent Avg. Grams
Allergy/Immunology 27,573 32.4% 13,875 36.0% 503
Primary Immune Deficiencies 23,997 28.2% 12,598 32.7% 525
Neurology 24,266 28.5% 9,649 25.1% 398
Guillain Barre Syndrome 5,921 7.0% 3,316 8.6% 560
CIDP 2,460 2.9% 2,067 5.4% 840
Alzheimer's Disease 1,468 1.7% 801 2.1% 546
Hematology/Oncology 14,236 16.7% 9,900 25.7% 695
Bone Marrow Transplant 6,133 7.2% 5,152 13.4% 840
Idiopathic Thrombocytopenic Purpura 2,953 3.5% 977 2.5% 331
Chronic Lymphocytic Leukemia 3,212 3.8% 1,349 3.5% 420
Cardiology 7,139 8.4% 570 1.5% 80
Kawasaki Disease 6,783 8.0% 271 0.7% 40
Dermatology 5,052 5.9% 1,145 3.0% 227
Rheumatology/Nephrology 2,978 3.5% 2,078 5.4% 698
Infectious Disease 1,716 2.0% 674 1.8% 393
Ophthalmology 1,168 1.4% 394 1.0% 338
Obstetrics/Gynecology 948 1.1% 222 0.6% 234
Total 85,074 100.0% 38,507 100.0% 453
Source: MRB IVIg Industry Report 2009

Many of the diseases treated with IVIg therapy are chronic in nature and may be treated at home, generally with the assistance of a specialty infusion, home healthcare service company that includes home pharmacy and/or home nursing care. In recent years, home infusion of Ig administered subcutaneously (SCIg) has become increasingly popular. This mode of therapy has been shown to result in higher health-related quality of life as compared to hospital- or office-based intravenous therapy. For patients using SCIg at home, the role of the nurse is more limited and mainly consists of educating the patient or family to become independent in administering their own therapy (IDF 2007).

Projected Immunoglobulin Growth by Medical Specialty, Between 2009 and 2012


 

References
IDF 2007. IDF Guide for Nurses: On Immune Globulin Therapy for Primary Immunodeficiency Diseases, 2nd Edition. Towson Maryland, United States:  Immune Deficiency Foundation, 2007.

IVIg 2009. IVIg 2015: A Forecast of the Polyvalent Intravenous Immune Globulin (IVIg) Market in the United States in 2015. Orange Connecticut, United States: The Marketing Research Bureau, Inc., 2009.

Lin RY, Swartz RA “Immunoglobulin G Deficiency: Treatment & Medication” eMedicine from WebMD. July 2009 http://emedicine.medscape.com/article/136897-treatment

Nicolay U, Kiessling P, Berger M, et al. Health-related quality of life and treatment satisfaction in North American patients with primary immune deficiency diseases receiving subcutaneous IgG self-infusions at home. J Clin Immunol. Jan 2006;26(1):65-72.

Scheinfeld NS, Godwin JE “Intravenous Immunoglobulin” eMedicine from WebMD. Mar 2008 http://emedicine.medscape.com/article/210367-overview