Aprogen Develops Blood Non-Toxic Macrophage Immuno-Oncology Bispecific Antibody

Aprogen announced on the 9th that it has secured strong competitiveness in the multi-billion-dollar macrophage immune checkpoint anticancer drug market.

Aprogen, the only domestic new drug company holding an international patent for a bispecific antibody platform, announced on the 9th that it has succeeded in developing a CD47 bispecific antibody that significantly enhances the function of macrophages, which act as the body's primary immune defense line to attack cancer cells, while not killing red blood cells.

The CD47 bispecific antibody developed by Aprogen has about 1,000 times stronger ability to distinguish between cancer cells and red blood cells compared to magrolimab, developed by Gilead Sciences (hereafter 'Gilead') in the United States, resulting in very low hematologic toxicity, which is a drawback of magrolimab. In addition, the company greatly improved the ability to attack cancer cells while avoiding normal cells by applying bispecific antibody technology.

The industry is experiencing a boom in the development of CD47 immune anticancer drugs. In March 2020, Gilead acquired Forty Seven, the developer of the macrophage immune checkpoint anticancer antibody magrolimab, for $4.9 billion.

Magrolimab showed an ORR (overall response rate) of 92% and a CR (complete remission rate) of 50% in clinical trials combining azacytidine for myelodysplastic syndrome, and an ORR of 64% and CR of 55% for acute myeloid leukemia, confirming its therapeutic effect. Encouraged by this, Abbvie signed a license agreement worth $3 billion with I-Mab Biopharma to secure CD47 antibodies and CD47-based bispecific antibodies, and the following August, Pfizer invested $2.3 billion to acquire Trillium Therapeutics, which holds CD47 antibodies.

The most advanced in this CD47 immune anticancer antibody competition is Gilead's magrolimab. However, magrolimab has the drawback of binding very well not only to cancer cells but also to red blood cells, causing serious side effects such as anemia. According to Aprogen's own analysis, magrolimab binds only about 1.87 times better to the cancer cell line CEM7 and 6.8 times better to the cancer cell line NALM6 than to red blood cells. In other words, the degree of binding to red blood cells relative to cancer cells is still high, resulting in significant hematologic toxicity.

On the other hand, the bispecific antibody developed by Aprogen binds 1,879 times better to the cancer cell line CEM7 and 962 times better to the cancer cell line NALM6 than to red blood cells. In other words, Aprogen's CD47 bispecific antibody shows up to 1,000 times higher discrimination between red blood cells and cancer cells compared to magrolimab. This means that while magrolimab shows considerable hematologic toxicity at therapeutic effective concentrations, Aprogen's CD47 bispecific antibody is expected to have almost no hematologic toxicity. The company expects that, based on this superiority, its CD47 bispecific antibody will have strong competitiveness in the multi-billion-dollar immune checkpoint anticancer drug development market.

This content was produced with the assistance of AI translation services.