3SBio and Sequioa China led Refuge Biotechnologies' $25 million series B, which will advance the Bay Area biotech's dead Cas9-based cell therapies. The technology uses mutated Cas9 enzymes to switch specific genes on and off, controlling a cell's gene expression and resulting in therapeutic cells "that are programmed to make cancer-fighting decisions inside the patient's body."
Refuge is working on cell therapies based on its dCas9 platform, which doesn't cut DNA the way traditional CRISPR-Cas9 systems do. Instead, it acts as a carrier of transcriptional activators or repressors to specific targets in the genome.
Connecting dCas9 to a cell's membrane receptors enables them to sense their surroundings and activate or block gene expression depending on what they find. For example, therapeutic cells could be programmed to switch off the PD-1 gene when in the presence of a tumor cell.
The company has three CAR-T programs in the pipeline, in blood cancer and solid tumors. While its lead asset, RB-1916, is designed to inhibit PD-1 expression to treat diffused large B-cell lymphoma, the platform can be used to repress multiple checkpoint targets to boost treatment's potency and tamp down on side effects.
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"We have seen tremendous progress in the development of our technology and science, and believe that our receptor-dCas platform has the potential to create highly targeted cell therapies that bring superior efficacy while overcoming limitations related to toxic side effects," said Bing C. Wang, Ph.D., co-founder and chief executive officer of Refuge Biotech. "This financing will propel our efforts with our growing pipeline as we continue to design these innovative and intelligent cell therapies to fight cancer, and we are encouraged by the support from this top group of global investors."
The lead investors, 3SBio and Sequoia have the exclusive option to negotiate with Refuge on the right to develop and commercialize dCas9-based cell therapies in China. New investors Danhua Capital, Sangel Capital and Ocean Pine Healthcare Fund, as well as its existing backers, 3E Bioventures, WuXi Healthcare Ventures and ShangBay Capital also joined in the round.