Introduction to Biclonics®

Biclonics® are bispecific, full length human IgG antibodies. Merus utilizes a suite of technologies integrating the generation of large panels of high quality human antibodies and their rapid conversion into thousands of Biclonics® ready for functional screening in clinically relevant assays.

Merus Biclonics® Platform Capabilities

Human antibody generation

Merus uses its proprietary transgenic mouse MeMo® for the generation of diverse and high-quality panels of common light chain human monoclonal antibodies.


The product programs in the Merus pipeline are based on the Biclonics® format. Biclonics® are bispecific, full length human IgG antibodies.

Predictable in vivo behaviour

Data suggests that Biclonics® have IgG-like half life properties and low immunogenicity in humans.

High-throughput functional screening

Our functional screening assay has allowed us to learn that specific target combinations are indeed new targets and unlock novel biology.

Fc region engineering

CH3-engineering process has yielded essentially pure Biclonics® from single cells. The functional flexibility format of Biclonics® also allows for Fc-silencing for added safety and enhanced ADCC for high potency.


Our Biclonics® manufacturing process is compatible with standard platform monoclonal antibody manufacturing with yields of up to 4 g/L.

Biclonics® at work

Merus clinical programs are derived from the Biclonics® platform, and are selected from up to thousands of candidates using functional assays to select for specific characteristics. One example of the Bliconics® platform is Merus clinical pipeline candidate MCLA-128, an ADCC-enhanced bispecific antibody that utilizes our Dock & Block® mechanism. MCLA-128 is designed to further increase the immune-mediated killing capacity, and a full-length IgG format for potential long half-life, rapid intravenous administration and attractive dosing schedules for patients. Pre-clinical data suggests MCLA-128 has the ability to completely block heregulin-driven growth in tumor cell lines that are resistant to current HER2-targeting therapies. You can learn more about MCLA-128 and our unique Dock & Block® mechanism below.

Merus technology, process and the Biclonics® platform

Merus develops Biclonics®, innovative full-length human bispecific antibody therapeutics, which are based on the full-length IgG format and are designed to have several of the same features of conventional human monoclonal antibodies, such as long half-life and low immunogenicity. With Biclonics®, Merus can utilize unique mechanisms of actions and novel targets/target combinations. Candidates are derived from a sophisticated functional screening process for a given target combination and disease area.

Scientific Publications

To read more about Merus platform and its leading Biclonics® technology, please follow the link below for access to Merus scientific publications.

View Publications