Curing Leukaemia With HIV: Breakthrough On Treatment For Cancer?

http://www.youtube.com/watch?feature=player_
embedded&v=dVvEIYlj_wA
http://www.youtube.com/watch?feature=player_
embedded&v=dVvEIYlj_wA
this 4 minute video shows an inspiring story of a
young girl, Emma who was cured of Leukaemia by
injecting her with HIV-modified T-Cells which were
then capable of attacking the cancer cells.
It is important though to get the correct information
on how it was actually done...
No, doctors did not "inject HIV into a dying
girl" to treat her cancer
Posted on June 25, 2013 by Kat Arney
We've recently noticed an inspiring short film
circulating on the internet about how doctors in
the US have apparently cured a child of
leukaemia by "injecting her with HIV".
But while the actual science behind this story is
fascinating, the treatment is still at an extremely
experimental stage and has only been tested in a
handful of patients.
And while we're always keen to welcome exciting
experimental cancer treatments, we also want to
clear up a few misconceptions about what the
research actually involved.
To be absolutely clear, the doctors in the video
did NOT inject HIV – nor a "deadly disease" – into
a child.
So who are these people, and what did they
actually do?
Turning the immune system on cancer
The research comes from Professor Carl H. June
and his team in Philadelphia in the US. He's a
highly-respected scientist working on cancer, HIV
and the immune system, and has published his
work in hundreds of papers in many leading
scientific journals over several decades.
The immune system is an incredibly hot topic in
cancer research. Cancer is an illness that starts
from our own cells going rogue within us. Our
immune system is pretty good at recognising and
attacking foreign invaders – such as bacteria or
viruses – but it doesn't do so well at tackling
tumours.
A huge amount of research effort around the
world is focused on trying to understand why the
immune system doesn't recognise and fight off
the disease. And there's also a lot of work aimed
at harnessing this powerful force for treating
cancer, and this is leading to new ways to treat
the disease.
Professor June and his team are taking an
interesting approach to this challenge. In
particular, they're developing new ways to turn
the power of the immune system on leukaemia –
a cancer caused by white blood cells (usually B
cells, also part of the immune system
themselves) growing out of control.
They've developed a technique in which they
collect special 'killer' immune cells, called T cells,
from a cancer patient. These are then
'reprogrammed' in the lab using a modified virus,
which is very good at smuggling genes into the T
cells.
In this case, the researchers added genes
carrying instructions that tell the T cells to make
a new protein called a "chimeric antigen
receptor" – this lets them lock on to molecules
found on the surface of cancer cells, killing them
in the process.
These reprogrammed T cells are then injected
back into the patient, where they grow and
multiply, creating an army of killer cells to fight
the disease.
At least, that's the theory.
From the lab to the clinic
The Philadelphia team has been working on this
technique for many years, developing it first in
the lab then testing it in animals with promising
results. They're now taking this a step forward,
into clinical trials with cancer patients.
The situation described in the video, where a
little girl called Emily Whitehead (referred to as
Emma in the film) undergoes modified T cell
treatment, isn't the first time this approach has
been tested in people. There's more than a
decade's worth of data looking at the safety and
effectiveness of virus-modified T cells in clinical
trials for treating people with HIV as well as
cancer.
In 2011, Professor June's team treated three
adults with chronic lymphocytic leukaemia (CLL)
with virus-modified immune cells as part of a
small, early-stage clinical trial. All three had
undergone several rounds of chemotherapy, yet
their cancer kept coming back. For two of them,
their cancer completely went away after the T cell
therapy – something known as "complete
remission". This was an important and
impressive result, although one that was
probably over-hyped in the media at the time.
Further results from the trial – totalling 10 adult
patients with CLL and two children with a
different type of leukaemia (acute lymphoblastic
leukaemia, or ALL) were announced at a scientific
conference at the end of 2012. The researchers
claimed that nine out of the twelve patients had
been treated successfully – presumably three of
the adult patients are from the 2011 paper, while
the two children are likely to be from the paper
we'll discuss shortly.
And in March this year, a team at Memorial Sloan-
Kettering Cancer Centre in New York published
results testing a similar approach in five adults
with ALL. In all five, the cancer vanished,
although four of them went on to have further
treatment so it's hard to say whether this therapy
was solely responsible for curing them. And for
the final patient, the cancer came back once the
reprogrammed T cells had died off in their body.
From what we can tell, the girl in the video –
Emily/Emma – is being treated as part of another
small-scale, early-stage clinical trial for children
with leukaemia and lymphoma, testing the virus-
modified T cell treatment. This is primarily a trial
to find out whether the treatment is safe, rather
than how well it works.
Results from two children with ALL were recently
published in a paper in the New England Journal
of Medicine. Of the two kids, one seems to have
had a complete remission – we can only assume
this might be Emily, though she isn't mentioned
by name in the paper. Sadly, the other child
didn't do so well. The cancer came back just two
months after the T cell treatment.
Obviously, for Emily and her family this
experimental therapy has been nothing short of a
miracle. But from the handful of cancer patients
treated so far, it's clear that it doesn't work for
everyone – something that's rightly pointed out
in the film.
The therapy also causes significant side effects,
dramatically described in the video. Several of
the patients who receive the modified T cells
seem to experience what's known as a "cytokine
storm" – a potentially fatal immune reaction.
Subjecting weakened cancer patients to such a
barrage is highly risky, so researchers need to
proceed with great caution as the clinical trials
continue recruiting patients.
How does HIV fit into the picture?
Promoting the video, the Upworthy website
boldly states that the doctors are injecting "HIV
into a dying girl", and that she received a "deadly
disease". This is a serious bending of scientific
truth, and very misleading.
In fact, the researchers are using a type of virus
called a lentivirus to reprogramme the T cells.
This family of viruses – of which HIV is a member
– are particularly skilled at sneaking into cells
and embedding their genetic code within the
cell's DNA. Unsurprisingly, this makes them a
good vehicle for smuggling in the genetic
instruction telling T cells to attack the cancer.
According to the video, Professor June says that
the virus used in these experiments was
originally derived from HIV, and we hear the film-
maker asking off-camera "So you're taking the
HIV virus and infecting healthy cells with it to
help kill cancer?" However, the virus has
undergone significant genetic tinkering, meaning
that it is no longer harmful (as June does go on to
explain). And it's arguable whether it should even
be referred to as HIV at all, given how much it has
been altered.
And the researchers didn't inject any virus into
anyone. As we've explained, they took immune
cells out of the patient, treated them with the
virus in the lab, then injected the modified cells
back in.
To sum up
Broadly speaking, we feel that this film is
inspiring, and we're always happy to see the
fruits of promising new therapies for cancer. But
to promote "injecting HIV" as a treatment is
misleading.
One child surviving 'incurable' cancer is an
amazing event, but there is a lot more work to be
done to find out how best to use this new
technology. At the moment it's still highly
experimental and expensive. It's only being
trialled in a very small number of patients,
primarily to make sure it is safe, and so far we've
seen that it doesn't work for everyone.
In the case of the child whose cancer came back
after treatment, the researchers found that her
cancer cells had somehow stopped carrying the T
cells' target molecule. So it's likely that other
targets will need to be identified, to make the
treatment more effective for more patients in the
future.
On a positive note, there's no reason why this
type of treatment should be restricted to cancers
affecting the immune system (namely leukaemia
and lymphoma), although they're much more
accessible to the killer T cells. Researchers
elsewhere are investigating how to target a range
of different types of cancer with this approach.
There are several similar therapies being tested
in the lab and in clinical trials around the world,
including in the UK. And Cancer Research UK
scientists are finding out whether harmless
genetically-engineered viruses could be used as
therapeutic vaccines, training the immune
system to seek and destroy cancer cells.
It's still early days for these exciting new
approaches and there are many hurdles to jump,
but we're looking forward to the day when they
can be used to treat patients on a wider scale.
http://scienceblog.cancerresearchuk.org/2013/06/25/
no-doctors-did-not-inject-hiv-into-a-dying-girl-to-
treat-her-cancer/