Analysis of Technical Advantages of Harbour BioMed's HarbourMice Antibody Platform

Based on the collected information, the technical advantages of Harbour BioMed’s HarbourMice antibody platform are mainly reflected in the following aspects:

HarbourMice platform includes two unique transgenic mouse technologies:

• Can generate classic fully human monoclonal antibodies in the form of double heavy chain and double light chain (H2L2)
• The hypervariable regions of the antibodies are fully human sequences, which are suitable for conventional antibody development using mature CDR grafting technology
• Can quickly and large-scale manufacture typical two heavy and two light immunoglobulin chain antibodies with modified fully human variable regions

• The world’s first platform using transgenic mice to produce functional fully human heavy chain-only antibodies
• The produced heavy chain antibodies are only half the size of conventional IgG antibodies, but have similar pharmacokinetic properties and Fc-mediated effector functions
• No humanization or other additional antibody engineering modifications are required

• Currently, there are only three recognized fully human heavy chain-only antibody platforms worldwide, and Harbour BioMed’s HCAb platform is the only one accessible to the outside world for antibody development
• This scarcity makes Harbour BioMed unique among domestic antibody biotech companies

• In principle, the R&D efficiency of the transgenic mouse platform can outperform the CDR route and even the phage library route
• High technical barriers make it difficult for competitors to copy quickly

The HarbourMice platform can develop various cutting-edge molecular forms:

• Bispecific/multispecific antibodies
  : Bispecific immune cell engagers developed based on the HBICE® platform
• Antibody-drug conjugates (ADC)
• CAR-T cell therapy
• mRNA therapy
• Nanobodies

• Since the HCAb platform does not contain light chains, it maximizes the solution to the problems of light chain mismatch and heterodimerization
• Able to develop products that are difficult to achieve with conventional antibody platforms

• Based on the HCAb platform, the company has independently developed the HBICE® platform, focusing on generating differentiated HCAb-based bispecific immune cell engagers
• Developed the HBICATM platform to support the R&D of innovative biopharmaceuticals in the field of immunological and inflammatory diseases

Mainstream global transgenic mouse platforms have been fully validated:

• Medarex’s HuMAb technology platform has accumulated 10 approved antibody drugs
• Abgenix’s Xenomouse platform has accumulated 6 approved antibody drugs
• These platforms were acquired by Amgen (2.2 billion USD) and Bristol-Myers Squibb (2.4 billion USD) respectively, demonstrating their great value

Harbour BioMed has established an end-to-end closed-loop workflow:

• AI HCAb sequence generation
• AI-guided design and screening (AI classification model and druggability prediction)
• Wet experiment validation
• Transforms HCAb discovery from ‘finding a needle in a haystack’ to ‘AI selection’, significantly improving the efficiency and accuracy of antibody discovery

In summary, the core technical advantages of the HarbourMice platform lie in its global scarcity of fully human heavy chain-only antibodies, broad application scenarios, and ability to solve pain points in traditional antibody development. These advantages enable Harbour BioMed to have a significant differentiated competitive advantage in the field of innovative antibody drug research and development.