The Technology

Aadi Bioscience’s first product, ABI-009, nanoparticle albumin-bound sirolimus (rapamycin), a highly active form of sirolimus complexed with albumin, is based on the same technology as Abraxane┬« (nab-paclitaxel, Abraxis Bioscience, acquired by Celgene Corp in 2010 for ~$3B, 2017 sales $992M). The albumin-bound platform technology was invented and developed by Dr. Desai and colleagues at Abraxis.

Albumin is highly accumulated in tumor tissues, either due to the leaky capillary system and defective lymphatic drainage of tumors [1] or through an active gp60/caveolae-mediated transport process across tumor blood vessel endothelium [2, 3]. Importantly, albumin is taken up by proliferating tumor cells via endocytosis and macropinocytosis, then catabolized by lysosomal degradation to support de novo protein synthesis, energy, and tumor growth [4]. The accumulation of albumin in solid tumors provides potential rationale for albumin-based drug delivery systems to preferentially target tumors. The nab technology enables sirolimus to associate with albumin through non-covalent hydrophobic interactions to create a suspension of nanoparticles with a size of about 100 nm.

[1] Kratz F (2008). J Control Release 132, 171-183.
[2] Desai N et al (2006). Clin Cancer Res 12, 1317-1324.
[3] Minshall RD et al (2000). J Cell Biol 150, 1057-1070.
[4] Commisso C et al (2013). Nature 497, 633-637.