Alright, with China quarantine measures I have some time to make an analysis of the 3 new posters from last week. Only going to cover the relevant new bits of information.
-- Derralynn Hughes poster: Basically this poster is looking at the BLISS score of the Phase I/II study. We already had some BLISS score data before but this poster goes into much more detail.
BLISS score is effectively looking at the amoung of the target fatty substrate GB3, in the Kidney Peritubular Capillaries (PTC). It is the build up of this in the target organs that leads to their degradation. So reducing this is good.
First let us remember that in the Phase I/II study there were 3 dosage regimens being investigated, 0.2mg/kg, 1mg/kg and 2mg/kg. So let us bear in mind that the subjects in the 0.2mg/kg data set could have the ability to negatively skew results as we are only here provided the data on the overall or gender level. The data is also from 14 of the 16 evaluable patients in the Phase I/II at the 6 month mark for BLISS, and out to 12 months for Plasma lyso-GB3, which is the lysosomal GB3 that has gotten out into the bloodstream, hence 'Plasma'.
On Kidney GB3 'BLISS' score the result after just 6 months are staggering, with an approx 70% reduction in GB3 in the kidney PTCs. The therapeutic effect is more pronounced in the males in this study compared to females at 85% reduction and 48% reduction in females. Though this more pronounced effect in males is to be expected at they suffer more from Classic Fabry and have a higher baseline of kidney GB3 to act on.
Not only do we see this as wonderful data but this also corroborates the understand that a considerable amount of enzyme is making it into the target organs. And not being degraded by anti-bodies in the bloodstream or being broken down by the liver like for current ERTs.
This activity is further corroborated by the again staggering decrease in Plasma Lyso-GB3. This Plasma GB3 being the first to be acted on by PRX-102 via the infusion of the enzyme into the bloodstream. We see a 81% decrease in the overall sample, with 86% reduction in males and 72% reduction in females, even though the female were at a relatively low baseline already. 78%, 71% and 64% achieved reduction in BLISS score of >50%, >60% and more than 70% respectively. Quite astounding.
This clearly shows the enzyme doing it's job where it needs to be doing it. And also thereby gives credence the effect halting of eGFR slope decline that was seen in these subjects at the 24 month mark.
--David Warnock Poster & Oral presentation effectively look at the same data:
This poster mainly looks at the baseline characteristics of the BALANCE subjects that have been treated on Fabrazyme, and essentially pointing out how ineffective Fabrazyme was for them.
Of the 75 subjects, 23% had an eGFR of >90, the great majority 51% had worse eGFR of 60-90, and the final 27% had a terrible eGFR of 30-60.
so 78% of the patients are already in very bad straits indeed, and 23% are doing ok physiologically at the moment, however what is more important going forward is their annualised eGFR slope on Fabrazyme. Where we can see on the poster than these same 3 groups have an annualised reduction in eGFR of -8, -7.85 and -9.34 respectively. This being a far cry from the -2.2 that Fabrazyne notes having achieved in their pivotal Phase II for approval. At these rates, even a normal person with an eGFR of 100 would being on dialysis in 12 years.
Now compared that to the Replagal bridge data of eGFR of -5.1 on Replagal to -0.23 seen in the interim Bridge data, and we can see clearly how even in these patients are benefiting very much from PRX-102. Given that the BALANCE study subjects are actually on an even worse baseline than than the BRIDGE subjects I believe would provide a range for which the effect of PRX-102 could be even more pronounced. But probably still having a final 0.2-0.5 eGFR slope on PRX-102 in these same BALANCE subjects.
--Dr Ales Linhart poster: Looks at full year (12 month) eGFR data of the first 16 BRIDGE study subjects, 9 males, 7 females.
From Replagal usage, Baseline eGFR was -5.1 with -5 in females and -5.2 in males. Basically terrible, but not as bad as the baseline on Fabrazyme of the BALANCE subjects above.
After the full 12 months of the study, the eGFR slope improved by 4.9, leading to the 0.23 eGFR slope on PRX-102.
When looking at the severity of the Kidney disease. there was a 67% increase in the number of Stable Disease patients (from 6 to 10), a 25% reduction in Progressing Disease (4 to 3), and a 50% reduction in Fast progressing Disease (6 to 3). This last data shows that while things are improving for all groups, specifically the Fast Progressors, Slower Progressors on Replagal are both also seeing benefit from PRX-102. No-one appears worse off after switch and a good amount see improvements and an over 4.9 improvement at that.
All very good signs individually and collectively.
AI
