Addition of VX-661 to KALYDECO(R) (ivacaftor) Improves Lung Function short study P2

[CFParent2]

At first, I was a little confused about the results from this 4 week study. Here is my summary of what happened.

They took people who were already taking Kalydeco and then also gave some of them VX-661. These people had one gene that was DelF508 and the other gene was one of the G551D genes that have already been shown responsive to Kalydeco. They were able to see additional improvement. The hope is that they might have also corrected the DelF508 gene. If that is true, then they may be able to help the more people who just have two DelF508. Next step is to do a longer (12 week Study). All in all this is very encouraging.

Interesting point that they did not test the younger healthier population this time and they switched the primary endpoint from FEV1 to the sweat Chloride test and safety. This seems to be good move since FEV1 is a very indirect measure of cellular correction.

Please don't take my word read the full release.

http://investors.vrtx.com/releasedetail.cfm?ReleaseID=844677

 

[Aboveallislove]

Actually they did test fev and sc, and in other studies have dumped sc because it doesn't correlate to clinical benefit. They have already tested in dd508 for 28 days with similar results...but all very good because it show you can improve by attacking one mutation...get better benefit for those who benefit from lay deco, and safety is still good which is key for three drug combo.

 

[CFParent2]

Actually they did test fev and sc, and in other studies have dumped sc because it doesn't correlate to clinical benefit. They have already tested in dd508 for 28 days with similar results...but all very good because it show you can improve by attacking one mutation...get better benefit for those who benefit from lay deco, and safety is still good which is key for three drug combo.

Yes, I had heard that SC was not correlating to clinical benefit. Maybe it is due to the clinical benefit they were looking for had to be seen within the short trial period. I wonder how much variation in three months is typical for FEV1. My son's FEV1 went from about 91 all the way up to 110 during a 3 month period, with minimal intervention. Anyone else seen this much variation without outside intervention?

Maybe when they have ways to fix the ion transfer at all process levels, there will be better clinical correlation with SC.

 

[Aboveallislove]

The study showed the FEV change statistically significant to a pretty high degree, which means that there is a very high probability that the change is due to drug and not happenstance.

 

[Gammaw]

We have seen similar Fev1 variations without intervention over a 3 month period. The pulmonologist is seeing a pattern though depending on the seasons and attributes it to an asthma/allergy type response.

 

[CFParent2]

Statistics

The study showed the FEV change statistically significant to a pretty high degree, which means that there is a very high probability that the change is due to drug and not happenstance.

As excited as I am about having new drugs enter the market, I know enough about statistics to know that using test sizes of < 100 of nearly anything with even a small amount of variation is not statistically significant. That said you can only work with what you have available. Pretty funny how the mathematical definitions get blurred in the the name of progress.

 

[Aboveallislove]

I know with small sample sizes it is hard to get stat sign, but the study results specified the p value which showed it was stat significant. My understanding is that to get that p value you have to consider the sample size...what am I missing/misunderstanding?