PEG-INTRON® treatment for hepatitis C

Pegylation is a process whereby a substance called polyethylene glycol (PEG) is attached to a protein in order to extend protein activity. PEG is used in everyday products, such as foods and cosmetics. When used in prescription medications, active substances stay in the body longer before they are broken down and eliminated.

Interferon alfa-2b was developed by Schering Hepatitis Innovations as the first FDA-approved therapy for hepatitis C. Now with Schering's pegylated interferon, PEG-INTRON®, polyethylene glycol is attached to a standard interferon (alfa-2b) molecule. This allows the interferon to stay in the body longer to help maximize treatment outcomes.

Standard interferon only stays in the body for about a day. Pegylated interferon from Schering provides longer, more constant drug levels to better suppress the hepatitis C virus. Pegylated interferon also allows for once-weekly dosing, compared to dosing three times a week with standard interferon. This means fewer shots over your course of treatment. In fact, people on PEG-INTRON® can experience 2/3 or 104 fewer injections over a one-year treatment course. And fewer shots can mean less time worrying about your disease and more time getting on with your life.

WARNING
Alpha interferons, including PEG-INTRON®, cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory evaluations. Patients with persistently severe or worsening signs or symptoms of these conditions should be withdrawn from therapy. In many but not all cases these disorders resolve after stopping PEG-INTRON therapy.

There are no new adverse events specific to PEG-INTRON® as compared to INTRON® A (Interferon alfa-2b, recombinant) for Injection, however, the incidence of some (eg, injection site reactions, fever, rigors, nausea) were higher. The most common adverse events associated with PEG-INTRON® were "flu-like" symptoms, occurring in approximately 50% of patients, which may decrease in severity as treatment continues. Application site disorders were common (47%), but all were mild (44%) or moderate (4%) and no patient discontinued, and included injection site inflammation and reaction (ie, bruise, itchiness, irritation). Injection site pain was reported in 2% of patients receiving PEG-INTRON®. Alopecia (thinning of the hair) is also often associated with alpha interferons including PEG-INTRON®.

Psychiatric adverse events, which include insomnia, were common (57%) with PEG-INTRON®, but similar to INTRON® A (58%). Depression was most common at 29%. Suicidal behavior including ideation, suicidal attempts, and completed suicides occurred in 1% of patients during or shortly after completing treatment with PEG-INTRON®.

PEG-INTRON® is contraindicated in patients with autoimmune hepatitis and decompensated liver disease.

The following serious or clinically significant adverse events have been reported at a frequency < 1% with PEG-INTRON® or interferon alpha: Severe decreases in neutrophil or platelet counts, hypothyroidism, hyperglycemia, hypotension, arrhythmia, ulcerative and hemorrhagic colitis, development or exacerbation of autoimmune disorders including thyroiditis, RA, systemic lupus erythematosus, psoriasis, pulmonary disorders (dyspnea, pulmonary infiltrates, pneumonitis and pneumonia, some resulting in patient deaths), urticaria, angioedema, bronchoconstriction, anaphylaxis, retinal hemorrhages, and cotton wool spots.

Renal failure patients should be closely monitored for signs and symptoms of interferon toxicity and PEG-INTRON® should be used with caution in patients with creatinine clearance < 50 mL/min. Patients on PEG-INTRON therapy should have hematology and blood chemistry testing before the start of treatment and then periodically thereafter.