Two HIV-positive patients who received bone marrow transplants for cancer now show no signs of the deadly virus.
Researchers Timothy Henrich and Daniel Kuritzkes, of Brigham and Women's Hospital and Harvard Medical School in Boston, announced last year that eight months after receiving healthy donor cells, the virus had not re-appeared in the patients' blood.
However, the patients were still taking anti-retroviral drugs at the time.
On Wednesday, Henrich and Kuritzkes said that the patients still appear to be HIV free even though they've stopped taking the drugs. They made the announced an international AIDS conference in Malaysia.
"While these results are exciting, they do not yet indicate that the men have been cured," Henrich said.