A second man may have been cured of HIV following treatment for leukemia and a stem cell transplant similar to what cured the virus in Timothy Ray Brown, the famed Berlin Patient, the National AIDS Treatment Advocacy Project (NATAP) reports.

However, since the man remains on standard antiretroviral (ARV) treatment, it is not known whether his virus would rebound without suppressive therapy.

Researchers presented information about the “Dusseldorf patient” at the International Congress on Drug Therapy in HIV Infection (HIV Glasgow).

In January 2011, the 41-year-old man was diagnosed with acute myeloid leukemia (AML), the same condition Brown had. Only recently diagnosed with HIV, he then began treatment for the virus and ultimately had a viral load of 44 and a CD4 count of 474.

He was treated for AML three times. In February 2013, during his second remission, he was given a transplant of unmodified peripheral blood stem cells from a donor who was homozygous for the CCR5-delta32 gene. This gene gives rise to immune cells that lack the CCR5 coreceptor on the surface immune cells onto which most HIV latches in order to infect cells. Thus it can lead to a natural resistance to the virus. Prior to the transplant, clinicians conditioned the man’s body with the drugs fludarabine and treosulfan.

The man remains on HIV treatment. The signs look promising that he may be cured, since highly sensitive tests, including biopsies from his rectum and bone marrow samples, have come up negative for HIV. Researchers intend to continue conducting tests to search for the virus in his body before they consider stopping his ARVs.