Hey Spiny and Pebbles,
Thanks for the plug with kind words about the D3 Regimen efficacy. After reading the article on galcanezumab-gnlm (Emgality) results when treating episodic CHers... all I can say is bless my long gray whiskers, the author of this article and the folks at Lilly who paid for this RCT must have been thinking pure thoughts.
Here's my analysis of the results. BTW, I've read the results from all the anti-CGRP monoclonal antibody RCTs for episodic migraine and episodic cluster headache... The published results of these RCTs tend to sugar coat the absolute efficacy of these mAbs with clever wording and relatively new measures of effectiveness like "Patient Global Impression of Improvement scale." In short, the results of these RCTs are at best fair with respect to prophylactic effect (headache prevention)... but not great... as a rating of great would be a complete cessation of headache symptoms...
To get the absolute efficacy of a cluster or migraine prophylactic intervention in an RCT you subtract the mean measure of improvement from the Placebo Control Group from the mean measure of improvement from Test Group taking in this case taking Emgality. In this RCT, the primary measurable endpoint was the reduction in CH frequency as indicated in the following quotes from the article/RCT...
"In this study there were 106 participants with episodic cluster headache who had an average of 17.5 cluster headache attacks per week at baseline."
Note: There's no discussion of how these 106 episodic CHers were divided between the Placebo Control arm and the Treatment arm...
The article when on to say "Across weeks 1 to 3 of the 2-month study period, the group treated with 300-mg galcanezumab reported a statistically significant difference in the reduction of weekly cluster headache attacks compared to placebo (-8.7 reduction for galcanezumab vs. -5.2 reduction for placebo; P = .036).
Note: There's no mention of efficacy at the end of the 2-month study period...
If you do the math, the placebo control arm of this RCT experienced decrease in average weekly CH from 17.5/week down to 12.3 CH/week (17.5 CH/week minus 5.2 CH/week). That also works out to 5.2/17.6 = 0.297 or a 29.7% reduction in CH weekly frequency Doing the same math on the treatment arm, Episodic CHers receiving 300-mg galcanezumab had a reduction in average weekly CH from 17.5 CH/week down to an average of 8.8 CH/week... and that works out to 8.7/17.5 = 0.497 or a 49.7% reduction in average CH/week.
Now lets look at the absolute efficacy by subtracting 29.7% for the placebo control arm from 49.7% for the Emgality treatment arm and to get an absolute average reduction in weekly CH of 20%. By the way you get the same 20% by subtracting 5.2 from 8.7 you get 3.5 and dividing by 17.5.
A better measure of efficacy is the number needed to treat (NNT) to achieve the stated improvement... in this case 3.5 fewer (20%) CH/week in one CHer. To get the NNT we divide 1 by the % improvement or 1/0.20 and we get 5. That means neurologists need to treat 5 episodic CHers to get on CHer to respond to this regimen... for an estimated $550 per treatment plus the neurology consult and labor of administering the Emgality injection and the bill per treatment comes to ~$750... assuming three months per treatment for an episodic CH cycle...
Now let's look at the efficacy of the anti-inflammatory regimen. Data from the online survey of 293 CHers taking this regimen since the survey started in Jan of 2011. This data indicates 80% of CHers who start this regimen experience an average 80% reduction in the frequency of their CH in the first 30 days and 50% of the CHers who start this regimen experience a complete and lasting cessation of of CH symptoms in the first 30 days These are combined figures for both episodic and chronic CHers...
There was no placebo control arm in this study, but we can use figures provided by a study run by a team of neurologists expert in treating CHers. They found the highest reported placebo response in CH of 14% to 43%. The lowest value was reported
using the strict endpoint; cessation of headache attacks. Using these figures to come up with the absolute efficacy we subtract 43% from 80% for a 37% reduction in CH frequency for 80% of CHers, we multiply 0.37 times the 0.8 we get 0.296. Dividing that into 1 we get 3.37 so round up to the next whole person for an NNT of 4 CHer taking this regimen to get one of them to have a favorable response.
Using the same math to get the absolute efficacy for a complete cessation of CH we subtract 14% from 50% for 36% or 0.36 and dividing that into one to get the NNT we get 2.77. Rounding up to the next whole CHer we have an NNT of 3 CHers treated with the anti-inflammatory regimen to get one CH to experience a CH pain free response. Using the same 3-month treatment period as the Emgality RCT, at 55 cents a day, the cost of this regimen for 3 months is $49.50.
Accordingly comparing efficacy of Emgality with an NNT of 5 for a 20% reduction in average weekly CH frequency for a cost $750 with the anti-inflammatory regimen at an NNT of 4 for one CHer to experience an 37% reduction in CH in average weekly frequency at a cost of $49.50 and an NNT of 3 to get one CHer a pain free response for $49.50... I think the nod goes to the anti-inflammatory regimen based on bang for the buck...
BTW this doesn't count the Emgality adverse side effects... Vitamin D3 has essentially none...
Take care,
V/R, Batch