Our Technology

F-star is developing novel, innovative tetravalent bispecific antibodies intended to transform the lives of individuals with hard-to-treat cancers.

Why tetravalency? In our quest to overcome many of the challenges facing current immuno-oncology therapies, we discovered that a 2 + 2 approach, with four binding sites, would drive strong dual immune activation capabilities.

  • Natural human antibody format means easier manufacturing with a favorable clinical safety profile
  • Four binding sites enhances targeted bispecific activity
  • Receptor clustering drives stronger biological potency than other bispecific approaches

F-star Therapeutics Bispecific Platform Explained

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Technology Platform

Our Bispecific Antibody Platform

F-star’s proprietary technology enables the creation of two additional distinct antigen binding sites in the Fc region of a natural antibody, termed an Fcab. The resulting tetravalent (2+2) mAbbispecifics bind simultaneously to two different antigens and are being designed to deliver focused, potent and safe immune activation.


Activating the Immune System with our Tetravalent Bispecifics

Our differentiated tetravalent mAb2 bispecifics are designed to enable safe, potent immune activation by:

  • CROSSLINKING. Bringing together two different cells, or two receptors on the same cell, to activate the immune system.
  • CLUSTERING. Receptors are brought together on the cell surface to activate key immune cell pathways.
  • CONDITIONALITY. Immune cells are only activated when their receptors are simultaneously bound by our bispecifics, which is designed to lead to safe activation.
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Our bispecifics are natural full-length human antibodies with substantial advantages for development:

  • Manufactured using well established manufacturing processes
  • No additional domains that may complicate manufacturing, such as domain assembly or other modifications

Introduction of the Fcab antigen binding sites does not interfere with binding to the Fc receptors. Mutations can be introduced into the Fcγ receptor binding sites to provide optimal immune activation, with a desirable safety profile.

The ability to engineer binding sites into an Fc region also provides the potential to create a number of other technology formats such as trispecifics and Fc-fusion proteins.


F-star develops novel bispecific antibodies to improve the treatment of serious diseases, with a focus on immuno-oncology.

Intellectual Property

F-star has built a comprehensive IP portfolio around its core technology and product pipeline that includes patents, trademarks and trade secrets.

With over 500 issued and pending patents to protect F-star’s mAb2 technology and pipeline, our IP portfolio provides exclusivity around both the Fcab and mAb2 technologies and their applications. It also covers Fcab and mAb2 products and their use in the treatment of disease.

F-star intends to continue seeking additional patent protection relating to its product candidates currently in development and as it develops additional novel mAb2 product candidates.