Peginterferon alfa-2a
- CAS Number: 198153-51-4
Peginterferon α -2a and peginterferon α - 2b, PEGylated drugs from the group of interferons. PEGylation is a bond the active substance with polyethylene glycol (PEG ), which allows a much slower release of the active ingredient (retardation).
Interferons were discovered in 1957 primarily as a cellular defense substances against the spread of viral infections in the tissue. Interferons have the ability to reinforce a defensive reaction of the body against some viral infections via a non-specific stimulation of T lymphocytes. Today is in addition to the anti-viral properties in addition, the anti -tumor effect in the foreground of therapeutic interest.
In the standard treatment of chronic hepatitis C pegylated interferons are used in combination with ribavirin. Peginterferon α -2b was the first pegylated interferon on the market and was under the product name PegIntron ® (then Essex Pharma, today - MSD - because of corporate merger / Merger ) approved on 25 May 2000 by the European Medicines Agency for the treatment of chronic hepatitis C. Peginterferon α -2b is a monopegylated derivative of interferon α -2b. Peginterferon α - 2a was launched in 2002 as a further development of the available since 1987 interferon α -2a under the trade name Pegasys ®, Roche on the market.
The special feature of the PEGylated interferon is a slower release of the drug from the bond with a polyethylene glycol ( PEG). Through the process of pegylation is so able to delay the renal clearance and prolong the plasma half-life of the interferon α -2b at 10 times (of about 4 hours to about 40 hours). Through this retarding effect occurs even serum levels that are necessary for an adequate and sustained stimulation of the immune response. An injection should only be done once per week therefore today. In the combination therapy with peginterferon α -2a and ribavirin α-2b/Peginterferon the respective dose is adjusted to the body weight of the patient.
In patients with chronic hepatitis C (genotype 2 or 3) a cure can be achieved in combination therapy for six months in about 75%. Patients with HCV genotypes 1 and 4 must be handled over twelve months, but still only achieve a cure rate of 50%. Even "hard- to-treat " patients, such as HIV / HCV co-infected patients in whom there is a special urgency for therapy due to the increased risk of hepatotoxicity of HAART can be successfully treated.
Since October 30, 2007 exists for combination therapy with peginterferon α -2b and ribavirin approval enlargement of the European Medicines Agency, which, re- treatment for relapse patients and nonresponders, not previously responded successfully to therapy with ( pegylated ) interferon / ribavirin allowed. The expanded approval is valid in all EU Member States and in Iceland and Norway. Peginterferon α -2a is approved as monotherapy for the treatment of hepatitis B.