A local gene therapy start-up has clinched a deal worth more than $1.2 billion with a global pharmaceutical giant to develop and eventually commercialise its treatments for rare genetic diseases.

Carmine Therapeutics, which was formed last year and says it is the first gene therapy company in South-east Asia, inked the deal on June 19 with Takeda Pharmaceutical, a research and development-driven Japanese multinational pharmaceutical company.

Gene therapy is a treatment where genes are injected into patients to fight or prevent diseases, instead of using chemicals or surgery.

Carmine developed a novel technology that uses tiny particles called extracellular vesicles, released by red blood cells, to deliver genes to parts of the body that need to be treated.

Once the particles reach the diseased cells or tissues, the genes help them build therapeutic proteins to restore their normal functions.

Carmine is unable to reveal the rare genetic diseases it is working on at this point.

It says it is the first company in the world to harness red blood cell extracellular vesicles as vehicles for gene therapy.

Most gene therapy treatments use viruses to deliver genes, but some patients may develop adverse immune responses to the viruses or reject them, said Carmine's founding vice-president, Dr Ronne Yeo.

In Carmine's therapy, only red blood cells from O-negative blood in blood banks are used because it has the lowest risk of causing adverse reactions in patients, he added.

Additionally, the vesicles from red blood cells are able to pack larger genes than viruses can, are cheaper to manufacture, and can access more organs than other vehicles.

The vesicles' ability to hold and deliver genes and their advantages over viral vehicles were discovered by two Singapore researchers, Dr Minh Le and Dr Shi Jiahai, both scientific co-founders of Carmine.

The start-up also says it is the first gene therapy company in Asia to use non-viral vehicles.

Its technology is called Red Cell EV Gene Therapy (Regent). The "EV" stands for extracellular vesicles.

"Developing alternative gene therapy delivery vehicles like the Regent platform that could address the challenges of (virus-based) gene therapy is critical to one day delivering next-generation cures for rare diseases," said Takeda's rare diseases drug discovery unit head Madhu Natarajan.

Carmine has been further developing the vesicles, engineering them to tackle different rare genetic diseases, and conducting pre-clinical studies. The company is also aiming to treat cancers with gene therapy in the future.

Mr Lin Xiangqian, Carmine's founding chief executive, said Takeda's funding and collaboration will help the start-up further optimise its technology and accelerate it towards clinical trials and commercialisation of the treatments.

"We are working very hard for patients with rare genetic diseases, and we are working to put locally developed biotech inventions on the world map," he added.