Gleaning stem cells from cloned monkey embryos, as a team of Oregon researchers has done, is an impressive step. But it probably won’t lead to medical treatments any time soon.

The promise of producing stem cells by cloning is that they can be genetically matched to a particular patient. So theoretically, doctors should be able to transplant tissue created from them into that person without tissue rejection. And presumably, such transplants could help treat such conditions as diabetes and spinal cord injury.

The process used in the new experiment is “quite inefficient,” Shoukhrat Mitalipov of the Oregon National Primate Research Center in Portland told reporters Wednesday.

He and his colleagues reported getting two batches of stem cells that required using about 150 monkey eggs apiece. That’s far too many if one hopes to use human unfertilized eggs, which are cumbersome to obtain from women. If further work can get that down to maybe five to 10 eggs per stem cell batch, “we will be closer to clinical applications,” Mr. Mitalipov said.

For now, he and other scientists said, the new work is valuable for showing that stem cells can be produced through cloning in monkeys. It’s been done in mice, but scientists had long been frustrated in their attempts in primates.