Positive results from clinical trials often give biotechnology companies a boost, but this one was big.

Shares of Sana Biotechnology, Inc. --a firm with a market capitalization of less than $400 million as of Tuesday's close--are up 217% in Wednesday trading. It announced clinical results for an in-human study on a Type 1 diabetes treatment that it says are positive. The treatment uses cell transplantation to help the body produce its own insulin.

The stock could soar even higher. Before the results were announced, the average target price among three analysts surveyed by Factset was $10.

"Today's data, when combined with progress elsewhere in the field, provide real hope that a scalable, curative treatment for patients with Type 1 diabetes, meaning normal blood glucose with no insulin injections or immunosuppression, is possible," said Per-Ola Carlsson, who led the study at Uppsala University Hospital.

The swings aren't particularly unusual for Sana, which was founded in 2018 and is headquartered in Seattle. It's now on track to close around the level last seen in August last year, and it's still down 87% from a high reached in 2021.