Sunday, November 21, 2010

Snarski Confirms Burt's Phase-I Results

First, a little background.   The "Burt" clinical trial in Brazil is one of the very few clinical trials which has actually cured people of type-1 diabetes.  I know that is a provocative statement, so let me be clear:  Some of the people treated in this trial did not need to use external insulin (yet still had reasonable A1C numbers while eating normal diets) for a long as the study ran.   Some of these people were followed for years.  This was not just a "couple of week" or even a "couple of months" event.  

But, there are important safety issues to consider with this treatment.  Basically, the treatment is to "reboot" the immune system, hobbling the immune system, and then treating it so that when it comes back, it does not attack the body's own beta cells.  There are two serious safety issues here: first, during the time the immune system is down, the patient must stay in an isolation ward in a hospital, and is subject to opportunistic infections.  Second, the act of shutting down the immune system is a big deal, and might cause problems "down the road".  Cancerous tumors are a particular worry.  Neither of these risks is completely unknown.   Very similar immune system "reboots" are used today to treat cancer, and some other autoimmune diseases and their safety is understood.  Never the less, the general level of safety is lower than other possible cures for type-1 diabetes.

So, with all that as prelude:
 

Snarski Confirms Burt's Phase-I Results
Second trial cures type-1 diabetes, in people, for months, but at what risk?

A Polish team has run a clinical trial very similar to Burt's, and gotten very similar results.  Since Burt's results are the best in terms of curing type-1 diabetes, this is good news indeed! 

The results from the published paper is pretty simple: 8 patients were treated, and 7 of them did not need external insulin again, for as long as they were followed.  They were followed for an average of 7 months (longest was 16 months).  The one who still required external insulin used about 10% of the dose before treatment.  In personal communication this group said that as of November 2010 they had treated 15 patients and that 11 of them had remained off insulin (median remission duration of 16 months).

This team used a protocol very similar to Burt's, although not identical.  However, the entire discussion of safety that applies to Burt applies here as well.

Some Discussion and Opinions

Because of the safety issues, I was interested in how many people volunteered for the treatment.  For this group, 19 patients were offered enrollment, and 8 accepted it.  So that means that basically 40% of the people who had the chance, considered this treatment "safe enough" to try it.  This was an adults only trial, so the people making the decision are making it for themselves (not for their children). I would assume that as this treatment becomes more common, the perceived safety would go up.

The researchers for this trial consider the chance of death from this treatment to be less than 1 in 100 (but are are not specific about how much below it is).


Encapsulated Beta Cells vs. Immune System Reboot: Head to Head Comparison

In terms of results in people, there are two approaches to type-1 diabetes which are head and shoulders above the others: Encapsulated Beta Cells (with LCT in the lead), and Immune System Reboot (Burt and Snarski).  No one else has cured type-1 diabetics for any length of time.  So here is a (slightly irreverent) head to head comparison:

Cure Rates

Encapsulated Beta Cells: less than 20% of the people go into remission for over two weeks.
Immune System Reboot:  more than 80% of the people go into remission for over two weeks.

For patients that did not go into remission, they generally used less insulin (for both treatments).  However, I think the drop was great for the reboot patients, but I don't have detailed data to support that.

Cure Duration
Encapsulated Beta Cells: averages less than 3 months.
Immune System Reboot: averages over 10 months.
Note: these are both very rough estimates!

Cure Safety

Encapsulated Beta Cells: Very safe: no known short term or long term side effects.  Out patient surgery.
Immune System Reboot: Less than 1% chance of death (but how much less?)  Also, very  small additional risk of cancers years or decades after the treatment.  Surgery and hospitalized recovery time, lasting many days.  No serious side effects seen so far.

Experience with the Cure

Encapsulated Beta Cells:  Less than 16 people, Max duration less than 2 years.
Immune System Reboot:  Over 30 people, max duration over 4 years (maybe 6 years in Brazil, I need to get updated information on that trial).
(This includes some personal communication from the Snarski group.)

Snarski Abstract: http://www.nature.com/bmt/journal/vaop/ncurrent/full/bmt2010147a.html
Burt Abstract: http://www.ncbi.nlm.nih.gov/pubmed/19366777
Another Abstract: http://www.ncbi.nlm.nih.gov/pubmed/19773265

Dr. E Snarski was kind enough to send me a pre-print of his group's paper, and provide valuable information for this blog posting.  Of course, all mistakes here are my own.  One comment that Dr. Snarski made very specifically was that "we should not yet talk about cure - rather the word remission should be used".  I used the word "cure" in some parts of this posting, but that's me.

Joshua Levy
All the views expressed here are those of Joshua Levy, and nothing here is official JDRF or JDCA news, views, policies or opinions. 
Blog: http://cureresearch4type1diabetes.blogspot.com
Web: http://joshualevy.pbworks.com/DiabetesCureReadyForHumanTrials

2 comments:

Igor said...

Sounds GREAT.

oakz said...

Thank you for this great news from Turkey! I am looking forward to it for my sister