LONDON (Reuters) - Shares in Sweden’s Hansa Medical jumped 12 percent on Thursday after research showed its experimental drug allowed doctors to perform successful kidney transplants in 24 out of 25 patients with a particularly high risk of organ rejection.

A donated kidney is the best treatment option for people with end-stage renal disease but some 30 percent of those on transplant lists have antibodies making them highly sensitive to donor organs, even with standard immunosuppressant drugs.

Hansa’s drug candidate IdeS - a bacterial enzyme that depletes such problem antibodies - offers a novel way to desensitize these patients so they can receive a new kidney that their bodies would otherwise reject.

There are currently no approved drugs for desensitization, making IdeS a potentially important new medicine for Hansa, which specializes in enzyme-based drugs for transplantation and acute autoimmune diseases.

Writing in the New England Journal of Medicine, researchers reported on the cases of 11 patients in Sweden and 14 in the United States who received IdeS before transplantation.

The new kidneys worked in all but one of the patients, although the scientists said their results “should be interpreted cautiously” given the small numbers involved.

Rx Securities analyst Joseph Hedden said the fact the transplanted kidneys continued to work well for at least six months indicated that IdeS could improve long term outcomes for difficult-to-treat patients.

He expects initial results in mid-2018 from a Phase II trial of IdeS that could potentially pave the way for regulatory approval.