Interferon alfa-2a dosage and administration

Interferon alfa-2a
PEGASYS® FDA Package Insert
Description
Clinical Pharmacology
Microbiology
Indications and Usage
Contraindications
Warnings and Precautions
Adverse Reactions
Drug Interactions
Overdosage
Clinical Studies
Dosage and Administration
How Supplied
Labels and Packages

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Dosage And Administration

Roferon-A recommended dosing regimens are different for each of the following indications as described below.

Note: Parenteral drug products should be inspected visually for particulate matter and discoloration before administration, whenever solution and container permit.

Roferon-A is administered subcutaneously.

Chronic Hepatitis C

The recommended dosage of Roferon-A for the treatment of chronic hepatitis C is 3 MIU three times a week (tiw) administered subcutaneously for 12 months (48 to 52 weeks). As an alternative, patients may be treated with an induction dose of 6 MIU tiw for the first 3 months (12 weeks) followed by 3 MIU tiw for 9 months (36 weeks). Normalization of serum ALT generally occurs within a few weeks after initiation of treatment in responders. Approximately 90% of patients who respond to Roferon-A do so within the first 3 months of treatment; however, patients responding to Roferon-A with a reduction in ALT should complete 12 months of treatment. Patients who have no response to Roferon-A within the first 3 months of therapy are not likely to respond with continued treatment; treatment discontinuation should be considered in these patients.

Patients who tolerate and partially or completely respond to therapy with Roferon-A but relapse following its discontinuation may be re-treated. Re-treatment with either 3 MIU tiw or with 6 MIU tiw for 6 to 12 months may be considered. Please see ADVERSE REACTIONS regarding the increased frequency of adverse reactions associated with treatment with higher doses.

Temporary dose reduction by 50% is recommended in patients who do not tolerate the prescribed dose. If adverse events resolve, treatment with the original prescribed dose can be re-initiated. In patients who cannot tolerate the reduced dose, cessation of therapy, at least temporarily, is recommended.

Chronic Myelogenous Leukemia

For patients with Ph-positive CML in chronic phase: Prior to initiation of therapy, a diagnosis of Philadelphia chromosome positive CML in chronic phase by the appropriate peripheral blood, bone marrow and other diagnostic testing should be made. Monitoring of hematologic parameters should be done regularly (e.g., monthly). Since significant cytogenetic changes are not readily apparent until after hematologic response has occurred, and usually not until several months of therapy have elapsed, cytogenetic monitoring may be performed at less frequent intervals. Achievement of complete cytogenetic response has been observed up to 2 years following the start of Roferon-A treatment.

The recommended initial dose of Roferon-A is 9 MIU daily administered as a subcutaneous injection. Based on clinical experience,3 short-term tolerance may be improved by gradually increasing the dose of Roferon-A over the first week of administration from 3 MIU daily for 3 days to 6 MIU daily for 3 days to the target dose of 9 MIU daily for the duration of the treatment period.

The optimal dose and duration of therapy have not yet been determined. Even though the median time to achieve a complete hematologic response was 5 months in study MI400, hematologic responses have been observed up to 18 months after treatment start. Treatment should be continued until disease progression. If severe side effects occur, a treatment interruption or a reduction in either the dose or the frequency of injections may be necessary to achieve the individual maximally tolerated dose (seePRECAUTIONS).

Limited data are available on the use of Roferon-A in children with CML. In one report of 15 children with Ph-positive, adult-type CML doses between 2.5 to 5 MIU/m2/day given intramuscularly were tolerated.8 In another study, severe adverse effects including deaths were noted in children with previously untreated, Ph-negative, juvenile CML, who received interferon doses of 30 MIU/m2/day. 12

Hairy Cell Leukemia

Prior to initiation of therapy, tests should be performed to quantitate peripheral blood hemoglobin, platelets, granulocytes and hairy cells and bone marrow hairy cells. These parameters should be monitored periodically (e.g., monthly) during treatment to determine whether response to treatment has occurred. If a patient does not respond within 6 months, treatment should be discontinued. If a response to treatment does occur, treatment should be continued until no further improvement is observed and these laboratory parameters have been stable for about 3 months. Patients with hairy cell leukemia have been treated for up to 24 consecutive months. The optimal duration of treatment for this disease has not been determined.

The induction dose of Roferon-A is 3 MIU daily for 16 to 24 weeks, administered as a subcutaneous injection. The recommended maintenance dose is 3 MIU, tiw. Dose reduction by one-half or withholding of individual doses may be needed when severe adverse reactions occur. The use of doses higher than 3 MIU is not recommended in hairy cell leukemia.

References

Adapted from the FDA Package Insert.