Gammaplex

GAMMAPLEX 5% is an Immune Globulin Intravenous (Human), 5% 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 (XLA), congenital agammaglobulinemia, Wiskott-Aldrich syndrome, and severe combined immunodeficiencies.

GAMMAPLEX 5% is indicated for the treatment of chronic immune thrombocytopenic purpura (ITP) to raise platelet counts.

• GAMMAPLEX 5% is a clear or slightly opalescent, colorless or pale yellow liquid. Parenteral drug products should be inspected visually 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.
• Do not freeze, and do not use any solution that has been frozen.
• Do not shake.
• GAMMAPLEX 5% should be at room temperature (up to 25°C [77°F]) at the time of administration.
• Do not use GAMMAPLEX 5% beyond the expiration date on the product label.
• The GAMMAPLEX 5% vial is for single use only. Due to the absence of anti-microbial preservatives, promptly administer GAMMAPLEX 5% after piercing the cap. Dispose of partially used or unused product.
• Infuse GAMMAPLEX 5% using a separate infusion line.
• Do not mix GAMMAPLEX 5% with other intravenous medications (including normal saline) or other IGIV products.
• An infusion pump may be used to control the rate of administration.
• If large doses of GAMMAPLEX 5% are to be administered, several vials may be pooled using aseptic technique. Begin infusion within 2 hours after pooling.

• Hydrate the patient adequately prior to the initiation of infusion.
• Due to the absence of anti-microbial preservatives, promptly administer GAMMAPLEX 5% after piercing the cap.
• Infuse GAMMAPLEX 5% 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 5% administration may vary. If the patient (a) has not received GAMMAPLEX 5% 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 5% infusion.
• Certain severe adverse reactions may be related to the rate of infusion. Slowing or stopping the infusion often allows the reaction to disappear.
• 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 5% at the minimum infusion rate practicable. Consider discontinuing GAMMAPLEX 5% administration if renal function deteriorates [see Boxed Warning, Warnings and Precautions (5.1, 5.2, 5.8)].

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 5%. 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 5% 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 5% and at appropriate intervals thereafter. If renal function deteriorates, consider discontinuing GAMMAPLEX 5%.

Thrombosis may occur following treatment with immune globulin products, including GAMMAPLEX 5%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 5% 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)].

Severe hypersensitivity reactions may occur [see Contraindications (4)]. In case of hypersensitivity, discontinue GAMMAPLEX 5% infusion immediately and institute appropriate treatment. Medications such as epinephrine should be available for immediate treatment of acute hypersensitivity reactions.

GAMMAPLEX 5% contains trace amounts of IgA (<10 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 5% is contraindicated in patients with antibodies against IgA and a history of hypersensitivity reaction [see Contraindications (4)].

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.

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.

GAMMAPLEX 5% 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 and 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.

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.

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

GAMMAPLEX 5% 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 5%. 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 5%, the physician should discuss the risks and benefits of its use with the patient [see Patient Counseling Information (17)].

• 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 5%.
• 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 5%, 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.

As 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.

As 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.

In addition to the adverse reactions identified in clinical studies [see Adverse Reactions (6.1)], the following adverse reactions have been identified during postmarketing use of GAMMAPLEX 5%:

• Infusion reactions: Dizziness
• Respiratory: Pulmonary embolism, dyspnea, respiratory distress
• Cardiovascular: Myocardial infarction, other thromboembolic event
• Neurological: Migraine, aseptic meningitis
• Integumentary: Rash, urticaria
• Musculoskeletal: Musculoskeletal pain

The following adverse reactions have been identified during postmarketing use of intravenous immune globulins⁹:

• Infusion reactions: Hypersensitivity (e.g. anaphylaxis), headache, diarrhea, tachycardia, fever, fatigue, dizziness, malaise, chills, flushing, urticaria or other skin reactions, wheezing or other chest discomfort, nausea, vomiting, rigors, back pain, myalgia, arthralgia, and changes in blood pressure
• Renal: Acute renal dysfunction/failure, osmotic nephropathy
• Respiratory: Apnea, Acute Respiratory Distress Syndrome (ARDS), TRALI, cyanosis, hypoxemia, pulmonary edema, dyspnea, bronchospasm
• Cardiovascular: Cardiac arrest, thromboembolism, vascular collapse, hypotension
• Neurological: Coma, loss of consciousness, seizures, tremor, aseptic meningitis syndrome
• Integumentary: Stevens-Johnson syndrome, epidermolysis, erythema multiforme, dermatitis (e.g. bullous dermatitis)
• Hematologic: Pancytopenia, leukopenia, hemolysis, positive direct antiglobulin (Coombs') test
• Gastrointestinal: Hepatic dysfunction, abdominal pain
• General/Body as a Whole: Pyrexia, rigors

Use caution when administering GAMMAPLEX 5% 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 5% at the minimum infusion rate practicable.

Eight patients with primary humoral immunodeficiency at or over the age of 65 years were included within the clinical evaluation of GAMMAPLEX 5%. This number of geriatric patients was too small for separate evaluation from the younger patients for safety or efficacy [see Clinical Studies (14)].

In a Phase 3 multicenter, open-label clinical trial to evaluate the efficacy and safety of GAMMAPLEX 5% in chronic immune thrombocytopenic purpura, 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 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 5% has a shelf-life of 36 months.

Keep GAMMAPLEX 5% in its original carton to protect it from light.

Do not freeze.