Hemophilia, a disease linked with legends of European monarchs, frail heirs and one flamboyant charlatan called Rasputin, still afflicts many people today.

And the very treatments that can help also can put patients’ lives at risk. The standard treatment is infusion with an expensively produced protein that helps the blood to clot. But in some patients the immune system fights the therapy and sets off an allergic reaction that can result in death.

Now researchers at the University of Florida and the University of Central Florida have devised a way that could someday help patients develop tolerance to the therapeutic protein before they are in need of treatment.

Hemophilia mostly affects males, and causes spontaneous internal bleeding or severe bleeding as a result of minor injuries. Many of these patients make multiple trips to the hospital and require intensive treatment that on average costs of up to one hundred-and-fifty-thousand dollars a year, according to the National Hemophilia Foundation.

The researchers set out to create a therapy that is less expensive and easier on patients, most of whom are very young. They genetically modified plants to encapsulate the therapeutic protein within cell walls so that when ingested, it can travel unscathed through the stomach and into the small intestines, where the immune system can act on it to induce tolerance. The system, now being tested in mice, is described in the Proceedings of the National Academy of Sciences.

Mice fed the encapsulated protein, then treated intravenously with the blood-clotting protein, didn’t produce inhibitors or develop allergic reactions.

Eventually the therapy could reach humans, although sadly, far too late for Rasputin’s young charge.