>> PEGGY PICO: It's the first of it's kind and one of only three in the world, neurosurgeons
call it gene therapy.
Here is Dr.�Clark Chen from UCSD.
This therapy provides treatment to certain types of tumors while leaving surrounding
tissue intact.
>>> That's right.
>> PEGGY PICO: What kind of brain cancer does it target?
>> It's a particular form of cancer that is the most frequent occurring of brain tumors
and it's one of the most devastating of cancers.
The average survival of for a patient who has been diagnosed is about 14 months and,
for instance, senator Kennedy expired about a year after he was diagnosed.
>> PEGGY PICO: And senator Kennedy was a public example of this.
What sort of symptoms does somebody who has this, what does the patient experience?
>> In the case of senator Kennedy he suffered a seizure and that eventually led to the diagnoses
of the cancer.
The presentation can be subtle.
I've had patients come to me saying they can't express themselves well and it turns out there
is a tumor in the area of speech.
And there are dramatic things like seizure and coma.
>> PEGGY PICO: What about treating brain tumors?
>> There is something called the blood brain barrier, a natural mechanism that you and
I have evolved to protect our brain from harmful chemicals.
The problem is if you have a brain cancer your chemotherapy is prevent from going into
the brain and we were trying to bypass that by injecting directly into the tumor.
>> PEGGY PICO: We have video.
Walk us through what happens here.
What's happening?
You're under an MRI, correct?
>> That's right.
So what you're seeing here is we're visualizing in realtime where the catheter that's going
to deliver it is.
To neurosurgeons this is extraordinary to be able to see the catheter in its location
as we're advancing it into the tumor.
>> PEGGY PICO: So you put it into the tumor and injecting what?
>> Injecting the gene therapy.
It's in the form of a virus that contains encodes a particular enzyme.
This enzyme converts a benign antifungal drug into a chemotherapy.
So the virus is engineered only to replicate and grow in the tumor.
As the tumor gets infected it makes this enzyme and they locally convert the therapy into
chemotherapy so the chemotherapy is only in the spot of the tumor.
>> And it causes the cell to selfdestruct?
>> That's right.
>> PEGGY PICO: How is this different from regular chemotherapy?
>> You take it into the vein or by mouth and it reaches every cell in your body.
In contrast, direct injection of this gene therapy into the tumor creates only chemotherapy
in the tumor.
So what that means is any of the side effects on non tumor cells is minimized.
>> PEGGY PICO: Are there side effects to the gene therapy treatment?
>> So far we haven't observed any but potentially there may be and we are carefully following
our patients for side effects.
>> PEGGY PICO: How many people in the clinical trial and so far what is the outcome?
>> We have treated a total of 12 patients and the results are very promising.
That said I have to caution that this is a phase 1 clinical trial we're looking at the
safety of the approach rather than the efficacy.
That said our patients are doing quite well.
>> PEGGY PICO: Could this procedure, if the next phase progressing and everything moves
as planned be used to treat other types of cancer?
>> Absolutely, it could be modified to treat cancer that can be imaged on the MRI?
>> PEGGY PICO: Is the trial going on and can people participate?
>> I would put a shout out there for patients who have suffered recurrence of this tumor
and at that point there is no standard of care and it's important to participate in
these trials so we can advance the therapist >> PEGGY PICO: Dr.�Clark Chen with the UCSD
Moores cancer center, thank you.
>>> Thank you for having me.