What is the Difference Between Chimeric and Humanized Antibody?

Chimeric and humanized antibodies are both types of monoclonal antibodies that have been modified for use in therapeutics. The main differences between them are:

1. Extent of humanization: Chimeric antibodies consist of rodent variable regions and human constant regions, while humanized antibodies have undergone a process called humanization, which involves replacing mouse constant regions and variable framework regions with human sequences. This process results in a significantly less immunogenic product.
2. Immunogenicity: Humanized antibodies carry a lower risk for inducing immune responses in humans than mouse or chimeric antibodies. However, they still contain murine-sequence derived complementarity-determining regions (CDRs) engrafted into human sequence-derived V regions. Fully human antibodies, on the other hand, have no murine sequence and are largely produced via phage display technologies or transgenic mice.
3. Production: Chimeric antibodies are created by combining rodent variable regions with human constant regions, while humanized antibodies are produced by grafting vital non-human amino acids over a human antibody framework. The human content is introduced more than in chimeric antibodies to reduce the risk associated with immunogenicity, while still maintaining the parent antibody's non-human components.

In summary, chimeric antibodies retain more rodent sequences and are less humanized than humanized antibodies, which have undergone a humanization process to reduce immunogenicity and improve tolerability in humans.

Comparative Table: Chimeric vs Humanized Antibody

Chimeric and humanized antibodies are both types of non-human antibodies that have been modified for use in therapeutic applications. They are monoclonal antibodies produced mainly by mice or rodents and are used to treat various conditions, including cancers. Here is a table highlighting the differences between chimeric and humanized antibodies:

The major difference between chimeric and humanized antibodies lies in the extent of amino acids of rodent origin retained in the variable regions. Chimeric antibodies contain a larger stretch of non-human protein, whereas humanized antibodies carry a lower percentage of non-human protein.