Welcome to Belrose Pharma official website
Contact : 609.917.3013


Site-Specific PEGylation

In 2013, Belrose Pharma acquired a comprehensive set of drug formulation technologies pioneered by publicly-traded Enzon Pharmaceuticals based on the chemical attachment of polyethylene glycol (PEG) using one of several chemical linkers designed to maximize the activity of a native molecule.

The FDA has approved a number of PEGylated pharmaceutical products since Enzon first pioneered the technique in the 1980s. Cumulative worldwide revenue of all PEGylated pharmaceutical products have exceeded $30 billion.


Currently Marketed PEGylated Pharmaceuticals

Adagen®: (PEG-adenosine deaminase) – for the treatment of Severe Combined Immunodeficiency Disease (SCID) (Enzon)
Oncaspar®: PEGylated L-asparaginase for the treatment of acute lymphoblastic leukemia in patients who are hypersensitive to the native unmodified form of L-asparaginase (Enzon). This drug was recently approved for front line use
PegIntron®: PEGylated interferon alpha for use in the treatment of chronic hepatitis C and hepatitis B (Schering-Plough/Enzon). Approved for use in the treatment of melanoma in 2011, and sold under the name Sylatron®
Doxil®/Caelyx®: PEGylated liposome containing doxorubicin for the treatment of cancer (Ortho Biotech/ Schering-Plough)

PEGASYS®: PEGylated interferon alpha for use in the treatment of chronic hepatitis C and hepatitis B (Hoffmann-La Roche)

Somavert®: (PEG-human growth hormone mutein antagonist) – for treatment of Acromegaly (Pfizer)

Neulasta®: PEGylated recombinant methionyl human granulocyte colony-stimulating factor for severe cancer chemotherapy-induced neutropenia (Amgen)

Macugen®: (PEGaptanib) – used to treat neovascular age-related macular degeneration (Pfizer)
Mircera®: PEGylated form of erythropoetin to combat anemia associated with chronic kidney disease (Roche)
Cimzia®: (Certolizumab Pegol) – for treatment of moderate to severe rheumatoid arthritis and Crohn’s disease, an inflammatory gastrointestinal disorder (Nektar/UCB Pharma)
Krystexxa®: (PEGloticase) – PEGylated uricase for the treatment of gout (Savient)
Omontys®: (PEGinesatide) – once-monthly medication to treat anemia associated with chronic kidney disease in adult patients on dialysis (Affymax/Takeda Pharmaceuticals)



Permanent PEGylation compounds have included enzymes, peptides and antibodies, with the chemical attachment of PEG used to improve these compounds’ half lives and toxicity profiles, along with other patient benefits achieved by maximizing the inherent biological activity of the native molecules. Currently marketed pharmaceutical products that demonstrate the legacy of Belrose Pharma’s proprietary Permanent PEGylation technology include Adagen®, CIMZIA®, Macugen®, Omontys®, Oncaspar®, PEGASYS®, PegIntron® and Sylatron®.

Watch the video for a compelling look at the timeline for these products’ development.



Permanent PEGylation, by increasing the molecular weight of a molecule, can impart several significant pharmacological advantages over the unmodified form, including:

  • Improved drug solubility
  • Increased drug stability
  • Enhanced protection from product degradation
  • Reduced dosage frequency, without diminished efficacy
  • Improved side effect profile, including reduced toxicity
  • Extended blood plasma half-life


Selected Articles on Permanent PEGylation:

Engineering an Arginine Catabolizing Bioconjugate
Structure-Function Engineering of Interferon-β-1b
Biodistribution and Excretion of radiolabeled 40 kDa PEG