Sana Biotechnology (SANA) reported Tuesday "positive" initial results from a study that transplanted islet cells into a person with type 1 diabetes without the use of immunosuppression.

Sana shares were rising 225% in recent after-hours trading.

The study showed that the company's hypoimmune, or HIP, technology enabled the transplanted islet cells to avoid rejection and produce insulin without immunosuppression, the company said.

"Results of the study at four weeks after cell transplantation demonstrate the survival and function of pancreatic beta cells as measured by the presence of circulating C-peptide, a biomarker indicating that transplanted beta cells are producing insulin," Sana said.

The study didn't identify any safety issues, the company said.