Unexpectedly, the stem cell treatment - from a donor with a mutation of the CCR5 gene, which is a co-receptor for the HIV-1 infection - ended up with Brown's HIV going into remission, where is has remained ever since.
The new case report comes more than 10 years after the first case, known as the "Berlin patient".
"By achieving remission in a second patient using a similar approach, we have shown that the Berlin Patient was not an anomaly and that it really was the treatment approaches that eliminated HIV in these two people", the lead researcher on the case, Ravindra Gupta, was quoted as saying by the broadcaster.
The breakthrough has come via bone marrow transplants that were meant to cure cancer in the patients, not the HIV virus.
Nonetheless, future research into how this HIV receptor functions could bring us a lot closer to an eventual cure for HIV, which now infects around 37 million people worldwide. Until now, Brown is the only person thought to have been cured of infection with HIV, the virus that causes AIDS.
This can prevent the virus being transmitted to others and give people with HIV a near-normal life expectancy.
Steven Deeks, an HIV researcher at UCSF, says the results could also boost cure efforts to cripple CCR5 "without the need for heroic interventions such as in the Berlin and London cases". That transplant also appeared to clear his HIV infection. "Those of us in the field have been waiting for a second cure via this approach", said Dr. Keith Jerome, one of the leaders of HIV cure research at the Fred Hutchinson Cancer Research Center.
Gupta and his team emphasized that bone marrow transplant - a unsafe and painful procedure - is not a viable option for HIV treatment.
Later that year, he was diagnosed with advanced Hodgkin's Lymphoma, a deadly cancer.
Sharon Lewin, an expert at Australia's Doherty Institute and co-chair of the International AIDS Society's cure research advisory board, told Reuters the London case points to new avenues for study.
This was the second time a man was cured of AIDS after receiving stem cells from a donor with a genetic mutation known to resist the killer virus.
The London patient underwent the transplant in May 2016, and in September 2017, stopped taking antiretroviral drugs.
For this reason, he's often described as being the first patient "cured" of HIV, although technically that's incorrect, since remission and cures are not the same thing (as sometimes remissions are not complete, if the viral load stages a resurgence). They also plan to present details in Seattle at the Conference on Retroviruses and Opportunistic Infections, which began Monday.
This would be crucial, according to researchers, since after the transplant, and an intense post-op treatment process that nearly saw Brown lose his life, he was cured of the virus and the cancer. There is still no trace of the virus after 18 months off the drugs.