5 times HIV was ‘cured’
15 March 2019
With news of another patient ‘cured’ we look back at 5 big moments in cure research and what they really mean
HIV cure news is, understandably, big news. Since HIV reached epidemic proportions in the 1980s, it’s become one of the world’s deadliest infectious diseases. Despite remarkable medical advancements and effective treatment meaning that HIV can now be a manageable chronic illness, any progress towards a cure is an achievement, met with excitement by news desks around the world.
So it was last week when news spread of a London man being ‘cured’ of HIV. The story broke during the Conference of Retroviruses and Infectious Diseases (CROI 2019) held in Seattle. Among those working in HIV, there was a sense of Deja-vu. Not so much in the case itself, but in the reporting of a ‘cure’.
We talk through the case and other reported HIV ‘cures’ that have hit the news.
1. London Patient (2019)
Last week’s exciting development describes a man living with HIV who received a stem cell transplant and is now in HIV ‘remission’, meaning he is off antiretroviral treatment (ART) and doctors are unable to locate any HIV in his body (although they know it’s there).
This is often called a ‘functional’ cure – or simply ‘cure’ by the media – because HIV is not completely eradicated in the body but it is not replicating or doing any harm that can be seen. Because of the emotiveness of the word ‘cure’, scientists prefer to use the word ‘remission’ in these cases.
Diagnosed with advanced Hodgkin’s Lymphoma, the stem cell transplant in combination with chemotherapy was used as a last resort for the man following failures to clear the cancer, as these transplants are complex and dangerous.
The stem cell donor had two copies of the CCR5 delta-32 gene, a rare genetic mutation that makes people naturally resistant to most types of HIV. The CCR5 enzyme is critical to HIV replication as it is the most common entry point HIV uses to infect cells, so in people with the mutation, this entry point is deactivated.
17 months following the successful transplant, with only mild treated graft versus host disease (GvHD), the man consented to ART interruption. He has now been in ‘remission’ for 18 months without viral rebound.
2. Berlin Patient (2008)
The ‘London Patient’ is not the first time a person has achieved long-term HIV remission through stem cell transplantation. There is one other stem cell transplant case researchers feel comfortable about declaring a ‘cure’. That is the case of Timothy Brown, also known as the Berlin Patient.
The London Patient investigators mimicked much of the case in Berlin, but with some important differences. In the first instance, Timothy Brown had late-stage leukaemia, but he also had to go through two stem cell transplants and total body irradiation – a highly aggressive course of chemotherapy. The London Patient received just one transplant with light chemotherapy.
Timothy Brown has been off ART now for over eight years, which is why doctors feel confident in declaring that he is ‘cured’.
“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,” said Professor Ravindra Gupta, lead author of the London Patient study by University College London (UCL) at CROI.
“Continuing our research, we need to understand if we could knock out this receptor in people with HIV, which may be possible with gene therapy,” said Professor Gupta.
3. Mississippi Baby (2013)
At the CROI conference in 2013, it was announced that a baby born with HIV in Mississippi, USA was functionally cured of HIV. The baby was given a strong dose of three antiretroviral drugs soon after birth, but their treatment stopped abruptly at 18 months when the mother was lost from care. When mother and baby returned to care five months later, the baby’s viral load was undetectable.
But just one year later, the landmark case took a significant blow when detectable levels of HIV were found again in the baby. Hence why, in cases such as the London patient, scientists are hesitant to declare a cure.
Even so, the case is important for research as it indicates that early, aggressive ART can result in short-term remission in children. We now also have a better understanding of how ART can control viral replication and limit the establishment of viral reservoirs. This is where groups of immune system cells may be infected with HIV, but where the virus is dormant and not being actively reproduced, and so also not causing any further damage. Understanding these will help us to find the key to long term viral suppression.
4. French Teenager (2015)
More recently, in July 2015, researchers announced that a French teenager who was infected with HIV at birth was still in good health 12 years after she last took ART. It is the longest known paediatric HIV remission case so far.
However, it is not yet known why she has fared better than the Mississippi baby – was there a biological reason? Would she have faired the same in the absence of treatment in the first place? Researchers cannot draw conclusions.
5. Visconti group (2012)
In a 2012 study, 14 French people living with HIV known as the ‘Visconti cohort’, started taking ART within 10 weeks of infection. After three years of medication, they stopped taking treatment, which would normally result in HIV re-emerging. Remarkably, they maintained low levels of HIV in their systems for an average of seven years before a recurrence of the virus emerged.
Another study, the 2018 ‘Control of HIV After Antiretroviral Medication Pause’ (CHAMP) study, also yielded similar results – some 13% of those treated in early infection were considered post-treatment controllers.
What does all this mean?
Aside from the advancements in cure research – the truth is we already have highly effective antiretroviral treatment that is giving people living with HIV the opportunity to live a near-normal life.
While this already an amazing achievement, there’s more to be done to improve the lives of people living with HIV – including combatting stigma, reducing pill burdens and removing sexual taboos. Cure research is just one of the ways that we can move the HIV response forward.
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