1.1 Primary Humoral Immunodeficiency (PI)

GAMMAPLEX 10% is an Immune Globulin Intravenous (Human), 10% Liquid indicated for replacement therapy in primary humoral immunodeficiency (PI) in adults and pediatric patients 2 years of age and older. This includes, but is not limited to, the humoral immune defect in common variable immunodeficiency, X-linked agammaglobulinemia, congenital agammaglobulinemia, Wiskott-Aldrich syndrome, and severe combined immunodeficiencies.

1.2 Chronic Immune Thrombocytopenic Purpura (ITP)

GAMMAPLEX 10% is indicated for the treatment of chronic immune thrombocytopenic purpura (ITP) in adults to raise platelet counts.

2.1 Dosage

2.2 Preparation and Handling

• GAMMAPLEX 10% is a clear or slightly opalescent, colorless or pale yellow liquid. Visually inspect parenteral drug products for particulate matter and discoloration prior to administration whenever solution and container permit. Do not use if the solution is cloudy or turbid, or if it contains particulate matter
• GAMMAPLEX 10% vials are for single use only. Dispose of partially used or unused product
• GAMMAPLEX 10% contains no antimicrobial preservatives. Therefore, prompt administration after preparation is necessary
• Do not shake
• Administer GAMMAPLEX 10% at room temperature (up to 25°C [77°F])
• Do not use any solution that has been frozen [see How Supplied/ Storage and Handling (16)]
• Infuse GAMMAPLEX 10% using a separate infusion line
• Do not mix GAMMAPLEX 10% with other intravenous medications (including normal saline) or other IGIV products
• An infusion pump may be used to control the rate of administration
• For administration of large doses, pool multiple vials using aseptic technique

2.3 Administration

• Hydrate the patient adequately prior to the initiation of infusion
• Infuse GAMMAPLEX 10% intravenously using an intravenous infusion set. See Table 1 for recommended infusion rates
• Monitor vital signs throughout the infusion
• Slow or stop the infusion if adverse reactions occur
• If symptoms subside, the infusion may be resumed at a lower rate that is comfortable for the patient
• The observation time of patients after GAMMAPLEX 10% administration may vary. If the patient (a) has not received GAMMAPLEX 10% or another IgG product, (b) is switched from an alternative IGIV product or (c) has had a long interval since the previous infusion, prolong the observation time for adverse reactions after GAMMAPLEX 10% infusion
• Certain severe adverse reactions may be related to the rate of infusion. Slowing or stopping the infusion often allows the reaction to disappear
• Close monitoring of the infusion rate in pediatric patients is recommended
• Ensure that patients with pre-existing renal insufficiency are not volume depleted
• For patients at increased risk of renal dysfunction, thrombotic events, or volume overload, administer GAMMAPLEX 10% at the minimum infusion rate practicable. Consider discontinuing GAMMAPLEX 10% administration if renal function deteriorates [see Boxed Warning, Warnings and Precautions (5.1, 5.2, 5.8)]

5.1 Renal Dysfunction/Failure

Acute renal dysfunction/failure, osmotic nephropathy, and death1 may occur upon use of human IGIV products. Ensure that patients are not volume depleted before administering GAMMAPLEX 10%. In patients who are at risk of developing renal dysfunction, because of pre-existing renal insufficiency, predisposition to acute renal failure (such as diabetes mellitus, hypovolemia, overweight, use of concomitant nephrotoxic medicinal products or age >65 years), administer GAMMAPLEX 10% at the minimum infusion rate practicable [see Dosage and Administration (2.3)].

Periodic monitoring of renal function and urine output is particularly important in patients judged to be at increased risk of developing acute renal failure. Assess renal function, including measurement of blood urea nitrogen (BUN) and serum creatinine, before the initial infusion of GAMMAPLEX 10% and at appropriate intervals thereafter. If renal function deteriorates, consider discontinuing GAMMAPLEX 10%.

5.2 Thrombotic Events

Thrombosis may occur following treatment with immune globulin products, including GAMMAPLEX 10%2. Risk factors may include: advanced age, prolonged immobilization, hypercoagulable conditions, history of venous or arterial thrombosis, use of estrogens, indwelling central vascular catheters, hyperviscosity and cardiovascular risk factors. Thrombosis may occur in the absence of known risk factors.

Consider baseline assessment of blood viscosity in patients at risk for hyperviscosity, including those with cryoglobulins, fasting chylomicronemia/markedly high triacylglycerols (triglycerides), or monoclonal gammopathies. For patients at risk of thrombosis, administer GAMMAPLEX 10% at the minimum dose and infusion rate practicable. Ensure adequate hydration in patients before administration. Monitor for signs and symptoms of thrombosis and assess blood viscosity in patients at risk for hyperviscosity [see Boxed Warning, Dosage and Administration (2.3), Patient Counseling Information (17)].

5.3 Hypersensitivity

Severe hypersensitivity reactions may occur [see Contraindications (4)]. In case of hypersensitivity, discontinue GAMMAPLEX 10% infusion immediately and institute appropriate treatment. Medications such as epinephrine should be available for immediate treatment of acute hypersensitivity reactions.

GAMMAPLEX 10% contains trace amounts of IgA (<20 micrograms/mL) [see Description (11)]. Patients with known antibodies to IgA may have a greater risk of developing potentially severe hypersensitivity and anaphylactic reactions. GAMMAPLEX 10% is contraindicated in patients with antibodies against IgA and a history of hypersensitivity reaction [see Contraindications (4)].

5.4 Hyperproteinemia, Increased Serum Viscosity, and Hyponatremia

Hyperproteinemia, increased serum viscosity, and hyponatremia may occur in patients receiving IGIV therapy. It is critical to clinically distinguish true hyponatremia from a pseudohyponatremia that is associated with or causally related to hyperproteinemia with concomitant decreased calculated serum osmolality or elevated osmolar gap, because treatment aimed at decreasing serum free water in patients with pseudohyponatremia may lead to volume depletion, a further increase in serum viscosity, and a possible predisposition to thrombotic events2.

5.5 Aseptic Meningitis Syndrome (AMS)

AMS may occur with IGIV treatment. AMS usually begins within several hours to 2 days following IGIV treatment. Discontinuation of IGIV treatment has resulted in remission of AMS within several days without sequelae3.

AMS is characterized by the following signs and symptoms: severe headache, nuchal rigidity, drowsiness, fever, photophobia, painful eye movements, nausea, and vomiting [see Patient Counseling Information (17)]. Cerebrospinal fluid (CSF) studies frequently reveal pleocytosis up to several thousand cells per cubic millimeter, predominantly from the granulocytic series, and elevated protein levels up to several hundred mg/dL, but negative culture results. Conduct a thorough neurological examination on patients exhibiting such signs and symptoms, including CSF studies, to rule out other causes of meningitis. AMS may occur more frequently in association with high doses (2 g/kg) and/or rapid infusion of IGIV.

5.6 Hemolysis

GAMMAPLEX 10% may contain blood group antibodies that can act as hemolysins and induce in vivo coating of red blood cells (RBCs) with immunoglobulin, causing a positive direct antiglobulin test (DAT) (Coombs' test) result and hemolysis4. Delayed hemolytic anemia can develop subsequent to IGIV therapy due to enhanced RBC sequestration; acute hemolysis, consistent with intravascular hemolysis, has been reported5. Cases of severe hemolysis-related renal dysfunction/failure or disseminated intravascular coagulation have occurred following infusion of IGIV.

The following risk factors may be associated with the development of hemolysis following IGIV administration: high doses (e.g. ≥2 g/kg), given either as a single administration or divided over several days, and non-O blood group6. Other individual patient factors, such as an underlying inflammatory state (as may be reflected by, for example, elevated C-reactive protein or erythrocyte sedimentation rate), have been hypothesized to increase the risk of hemolysis following administration of IGIV7, but their role is uncertain. Hemolysis has been reported following administration of IGIV for a variety of indications, including ITP and PI4.

Closely monitor patients for clinical signs and symptoms of hemolysis, particularly patients with risk factors noted above. Consider appropriate laboratory testing in higher risk patients, including measurement of hemoglobin or hematocrit prior to infusion and within approximately 36 to 96 hours post infusion. If clinical signs and symptoms of hemolysis or a significant drop in hemoglobin or hematocrit have been observed, perform confirmatory laboratory testing. If transfusion is indicated for patients who develop hemolysis with clinically compromising anemia after receiving IGIV, perform adequate cross-matching to avoid exacerbating on-going hemolysis.

5.7 Transfusion-related Acute Lung Injury (TRALI)

Noncardiogenic pulmonary edema may occur in patients following IGIV treatment8. TRALI is characterized by severe respiratory distress, pulmonary edema, hypoxemia, normal left ventricular function and fever. Symptoms typically appear within 1 to 6 hours following treatment.

Monitor patients for pulmonary adverse reactions. If TRALI is suspected, perform appropriate tests for the presence of anti-neutrophil antibodies in both the product and the patient's serum.

TRALI may be managed using oxygen therapy with adequate ventilatory support.

5.8 Volume Overload

Carefully consider the relative risks and benefits before prescribing the high dose regimen (for chronic ITP) in patients at increased risk of volume overload.

5.9 Transmissible Infectious Agents

As GAMMAPLEX 10% is made from human blood, it may carry a risk of transmitting infectious agents, e.g. viruses, the variant Creutzfeldt-Jakob disease (vCJD) agent and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent. No cases of transmission of viral diseases or CJD have been associated with the use of GAMMAPLEX 10%. All infections suspected by a physician possibly to have been transmitted by this product should be reported by the physician or other healthcare providers to Kedrion Biopharma, Inc. at 1-855-3KDRION (1-855-353-7466)

Before prescribing GAMMAPLEX 10%, the physician should discuss the risks and benefits of its use with the patient [see Patient Counseling Information (17)].

5.10 Laboratory Tests

• After infusion of immunoglobulin, the transitory rise of the various passively transferred antibodies in the patient's blood may yield positive serological testing results, with the potential for misleading interpretation
• Passive transmission of antibodies to erythrocyte antigens (e.g. A, B, and D) may cause a positive direct or indirect antiglobulin (Coombs') test
• Clinically assess patients with known renal dysfunction, diabetes mellitus, age greater than 65 years, volume depletion, sepsis, paraproteinemia, or those receiving nephrotoxic agents, and monitor as appropriate (BUN, serum creatinine, urine output) during therapy with GAMMAPLEX 10%
• Consider baseline assessment of blood viscosity in patients at risk for hyperviscosity, including those with polycythemia, cryoglobulins, fasting chylomicronemia/markedly high triglycerides, or monoclonal gammopathies
• Consider measuring hemoglobin or hematocrit at baseline and approximately 36 to 96 hours post infusion in patients at higher risk of hemolysis. If signs and/or symptoms of hemolysis are present after an infusion of GAMMAPLEX 10%, perform appropriate laboratory testing for confirmation
• If TRALI is suspected, perform appropriate tests for the presence of anti-neutrophil antibodies in both the product and patient's serum

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

6.2 Postmarketing Experience

Because adverse reactions are voluntarily reported post-approval from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to product exposure.

8.1 Pregnancy

8.2 Lactation

8.4 Pediatric Use

In pediatric subjects 3 years of age and older, the pharmacokinetics, dosage and safety are similar to those in adults.

8.5 Geriatric Use

Use caution when administering GAMMAPLEX 10% to patients aged 65 years and over who are judged to be at increased risk of developing renal insufficiency or thrombotic events [see Boxed Warning, Warnings and Precautions (5.1, 5.2)]. Do not exceed recommended doses, and administer GAMMAPLEX 10% at the minimum infusion rate practicable.

No subjects over the age of 55 years were included in the clinical study of GAMMAPLEX 10%. Eight (8) patients with PI at or over the age of 65 years were included within the clinical evaluation of GAMMAPLEX 5%. The number of geriatric patients was too small for separate evaluation from the younger patients for safety or efficacy [see Clinical Studies (14)].

12.1 Mechanism of Action

12.3 Pharmacokinetics

14.1 Treatment of Primary Humoral Immunodeficiency

14.2 Treatment of Chronic Immune Thrombocytopenic Purpura

The crossover bioequivalence study described in 14.1, above, did not include subjects with ITP. The results of the bioequivalence study comparing GAMMAPLEX 10% to GAMMAPLEX 5% in subjects with PI are supportive of the potential effectiveness of GAMMAPLEX 10% in the treatment of chronic ITP.

In a Phase 3 multicenter, open-label clinical trial to evaluate the efficacy and safety of GAMMAPLEX 5% in chronic ITP, of the 35 subjects enrolled from various ethnic groups, 9 were male and 26 were female. The age range was between 6 and 69 years. Subjects received intravenous infusions on two consecutive days (1 course) and then observed for a further 30 days. Individuals were given the option of a further two courses of treatment (if required), where only safety variables were assessed. Doses of GAMMAPLEX 5% ranged from 482 to 1149 mg/kg on Day 1 and Day 2. The median total dose per subject was 2035 mg/kg. Subjects received a total of 94 infusions (48 treatment courses).

All 35 subjects received at least one infusion of clinical trial drug, and all but one subject completed the first course of treatment.

The primary analysis was based on the platelet count achieved by Day 9 after the first course of treatment with GAMMAPLEX 5%, response being defined as a platelet count of 50 × 109/L or greater. Response to treatment on or before Day 9 was achieved by 29 of 35 subjects (82.9%), and the one-sided 97.5% lower confidence limit of the response rate was 66.4%, which met the a priori success criterion that required it to be greater than 60%.

Efficacy analyses included the duration of response, and changes in the incidences of bleeding or hemorrhage. At Day 32, the median (+ SD) platelet count (24 + [90] × 109/L) was still higher than the baseline value, and 11 of 33 subjects (33.3%) continued to show response of platelet counts of 50 × 109/L or greater. The median duration of platelet count response for the responders was 10 days.

There was an increase in platelet counts for the majority of subjects, and an overall reduction in the manifestations of bleeding after treatment compared to baseline (Day 1). Petechiae, hematomas and gastrointestinal, pulmonary and genitourinary bleeds were all either reduced or absent by Day 32.

There were no thromboembolic episodes reported in the clinical trial; and vital signs, biochemical, hematological and virology tests did not reveal any unexpected pathophysiology or toxicity.

When stored between 2°C [35.6°F] and 25°C [77°F]), GAMMAPLEX 10% has a shelf life of 36 months.

Keep GAMMAPLEX 10% in its original carton to protect it from light.

Do not shake.

Do not use GAMMAPLEX 10% beyond the expiration date on the product label.

Do not freeze.