The Importance of Fully Human Antibody Therapeutics

What are Fully Human Antibodies?

Antibodies from human sources consisting solely of fully human sequences
No murine sequences, which are commonly used in animal testing
Produced by using phage display technology to identify the desired human antibody genes, and then introducing the desired sequences into transgenic mice
Simplifies manufacture of antibody therapeutics due to lower expected immunogenicity compared to animal-derived antibody sequences
Antibody Development Trends
1970s Murine Antibodies image

Mouse Antibody Sequences

1980s Chimeric Antibodies image

Human Antibody Sequences

1990s Humanized Antibodies image

Human Antibody Sequences

Reduced Immunogenicity and Side Effects
2000s Fully Human Antibodies image

Human Antibody Sequences

Ratios in Global Antibody Therapeutics Development




  • Pharmacokinetic properties determining a drug’s safety and efficacy impacted by immunogenicity
  • Demonstrated advantage of fully human antibodies or at least humanized antibodies in clinical trials.

Number of Approved Antibody Therapeutics (Cumulative Total)

*Source: Immunotherapy Vol. 11, No. 2

The number of humanized or fully human antibodies among FDA-approved antibody therapeutics has been increasing each year.

  • Human
  • Humanized
  • Chimeric
  • Murine

The First Step in Developing a Fully Human Antibody Therapeutic from a Targeting Protein

Phage Display Technology


In phage display, genetic information of a target protein is inserted into the genome of a phage so that the target protein is exposed on the surface of the phage, enabling the production of fully human antibodies that are nearly identical to antibodies produced by the human body.

Phages, the smallest type of viruses, mainly infect bacteria. Because of their miniscule size, hundreds of billions can exist in just 1 mL of solution.

After the antibodies are presented on the surface of a phage, the process of selecting an antibody that binds to the target antigen becomes much simpler. Antibody presentation on the surface of the phage can be accomplished by inserting the genes of a human antibody into the phage’s genome through genetic engineering.

All antibody genes produced by a human body can be inserted into phage genes to create a collection of phages displaying the diverse antibodies. This collection of antibody-presenting phages is called a phage display library or human antibody library.

The key to producing a comprehensive human antibody library is to obtain every gene for each antibody produced in the human body and use molecular biology techniques that insert the antibody genes into the phage genes without any loss.

Ymax®-ABL, the Initiation Point of all Novel Therapeutic Antibody R&D at Y-Biologics

  • 01

    World-class Fully Human Antibody Library

    World-class naïve cDNA library of fully human antibodies

    More than 100 billion different antibody genes presented through phage display, a technology using genetic recombination to express proteins on the surface of viruses and enabling mass production of antibodies by finding specific enzymes that bind to antibodies

  • 02

    Launchpad for Each Pipeline Projects

    All novel antibodies discovered independently are selected from Ymax®-ABL

  • 03

    Increased Diversity and Excellent Antigen Binding

    Diversity enhanced by using a shuffling strategy during the manufacturing process

    Excellent antigen binding

  • 04

    Clinical Trials for YBL-006 in 3 Countries

    YBL-006, an anti-PD-1 immune checkpoint inhibitor, is a new therapeutic antibody candidate discovered from Ymax®-ABL and developed in-house that is currently undergoing Phase 1 clinical trials in Korea, Australia, and Thailand

  • 05

    High Sequence Similarity to Human Antibodies

    Lower immunogenicity, or the ability of an antigen to trigger an immune response, compared to synthetic libraries

    Superior antibody productivity and physical properties compared to synthetic libraries

Discovering Suitable Antibodies through Biopanning

Biopanning is the process of selecting an antibody pool that binds to a specific antigen from an antibody library. In our pursuit of discovering top-tier antibodies, this process is just as important as the diversity of our Ymax®-ABL library.

In acknowledgement of its importance, Y-Biologics is optimizing and applying a wide range of biopanning methods. In particular, we are developing and applying novel cell panning technology to antigens for antibodies which are challenging to screen and select.


Production of Antibodies with High Potential for Development

  • An antibody library
    with high diversity

  • A phage display system for labeling target proteins

  • Diverse biopanning methods to find the desired antibodies

  • An efficient system enabling prompt
    analysis of discovered antibody

  • High quality of
    antibodies discovered from the library