At a Boston AIDS conference, researchers announced that two patients affected with HIV had been virus-free after getting bone marrow transplants, weeks after they stopped using antiretroviral drugs, the New York Times reported.
This latest development in the search for curing the epidemic follows news of the so-called "Berlin patient," Timothy Ray Brown, whose results show no signs of the virus five years after also getting a bone-marrow transplant.
The procedure requires bone marrow from a donor who has a rare mutation that resists HIV.
However, the New York Times writes that "The Boston cases, like Mr. Brown's, are of no practical use to the 34 million people in the world who have H.I.V. but neither [have] blood cancer nor access to premier cancer-treatment hospitals."
But the cases are still seen to as improvements and further evolution in the search for an HIV cure.
Two teams are reportedly already studying variants of re-engineering patient cells to improve resistance to the infection, according to Dr. Steven G. Deeks, University of California AIDS researcher.
Dr. Françoise Barré-Sinoussi, who discovered the AIDS-causing virus and is the president of the International AIDS Society, said that the Boston patients findings were "very interesting and very encouraging."
The announcement about the cases was made at the society's annual conference in Kuala Lumpur, Malaysia, said the New York Times.
"The Berlin Patient" has sometimes been referred to as the very "first H.I.V. cure."
The procedure requires severely decreasing the ability of the immune system to function prior to a marrow transplant. The danger is so high that it has been deemed unethical for physicians to perform the procedure on people who are not already dying from cancer, since most people can live with the infection by taking a daily antiretroviral cocktail.
"One patient stopped taking antiretroviral drugs seven weeks ago. For the other, it has been 15 weeks. No virus or antibodies to the virus have been found in their blood or other tissues since," the New York Times writes.
The procedure on the two patients was very risky. A third patient reportedly died during the procedure after his cancer returned.
Brown had leukemia, while the three Boston trial patients had lymphoma.