LongBio Pharma Seeks Partners for High-Affinity SARS-CoV-2 Diagnostic Antibody Raw Materials

LongBio is a next-generation innovative biopharmaceutical company focused on the research and development of large-molecule antibody therapeutics. Leveraging its mature antibody discovery and antibody engineering platforms, LongBio has initiated the development of multiple Class 1 innovative drugs targeting various indications, with several projects scheduled to enter clinical trials sequentially this year.

Meanwhile, the Company has fully leveraged its technological advantages in the field of biomacromolecules to develop a variety of antibody-based raw materials for diagnostic assays, with quality meeting or approaching advanced international standards. Notably, the Company has successfully developed paired antibodies for SARS-CoV-2 antigen detection (comprising mouse monoclonal and rabbit monoclonal antibodies) and entered into a cooperation agreement with a domestic client. Using these antibody raw materials supplied by LongBio, the client successfully developed a SARS-CoV-2 antigen test kit (colloidal gold method), which received approval from the German Federal Institute for Drugs and Medical Devices (BfArM) and was listed on the whitelist permitting market access in the European Union and multiple other countries. Currently, registration applications for this test kit are underway in several countries.

This antibody pair (murine monoclonal antibody and rabbit monoclonal antibody) utilizes the SARS-CoV-2 nucleocapsid (N) protein as the antigen-binding site, featuring high affinity. It innovatively binds to distinct epitopes on the N protein, thereby ensuring efficient capture and detection. Binding assays against various viral variants demonstrate that these antibodies exhibit strong binding affinity not only for early strains of the virus but also for recently emerged variants such as Delta and Omicron, enabling robust detection.

According to the client's internal test results, this antibody pair (mouse monoclonal antibody + rabbit monoclonal antibody) demonstrates a detection sensitivity of over 1:50,000 for inactivated virus culture supernatant (i.e., a 50,000-fold dilution of the lysed viral stock), which is higher than that of other mainstream products on the market:

(Client Internal Test Results, for Reference Only)

Unlike the production models adopted by other raw material manufacturers on the market, the COVID-19 detection antibodies developed by LongBio are expressed using stable mammalian cell lines, offering differentiated advantages such as consistent quality, high yield per unit, and controllable costs. Antibody production adheres to cGMP standards, supported by a high-standard manufacturing environment and quality system. The current production process can meet supply demands at the 100-gram scale and can rapidly scale up antibody output in response to increased customer order volumes.