Share
1,640 Posts.
lightbulb Created with Sketch. 143
clock Created with Sketch.
02/05/18
21:38
Share
Originally posted by skint
↑
Chucke, I have always thought PBT434 has the potential be the better drug, maybe even possibly in HD and AD or in combination, and that the PBT434 clinical program was a good backup for the IMAGINE result. Considering the guidance from 2012 that Prana hoped for first in man trials (of PBT434) in 2014, I think we can all feel somewhat let down. In 2014 we knew the IMAGINE PBT2 AD trial was too small to evaluate even plaque load, but the Reach2HD (result 2013) were pretty good IMO for cognition in HD. It wasn't till Feb 2015 we found out that Prana would not be able to use the therapeutic level dose in the US, even after 8 safe human trials at that dose or higher. The FDA required "additional animal neurotoxicity studies OR identify a strategy for safely using a clinically relevant dosage in humans". The latter looked easily doable. Then there was Europe. In 2015 the EMA (European Medicines Agency) even awarded PBT2 orphan drug designation with some positive comments on the drug. In June 2015 the IMAGINE extension trial yielded excellent 2yr human safety results, which Prana had been waiting on for the Phase3 HD trial for PBT2. Suddenly there was a chink of light at the end of the tunnel. Things were looking great, "Planning underway for global (PBT2 HD)clinical trial in EU, Aust, US (US subject to FDA partial clinical hold)" (Nov2015) From the same presentation "Anticipated commencement of PBT434 Phase 1 program in 2016 (subject to regulatory approval)" Wonderful. But buried in that presentation was "We are required to establish how the dog study is not relevant to future PBT2 trials or in humans AND to describe a strategy to safely proceed with clinically relevant dosages in future clinical trials" The OR had become AND.
Then the FDA rejected Prana's plan for a safe trial outright as told to us in the Nov 2016 update. But Europe was still on the cards till the Dec update." Both agencies were encouraging of Prana’s development program for PBT2 but recommended further non-clinical work be undertaken and completed to establish the reversibility of the neurotoxicity effects seen in a dog study before further consideration of the Phase 3 trial."
I still don't understand why nobody took some dogs off the drug at the time and observed if the unwanted effect was reversible. How basic is that?
So that was PBT2 dead in the water IMO, Dec 2016, about 4 years after Reach2HD trial was completed July 2013, successful results reported Feb 2014.
"Carnage of the IMAGINE result." you say. That was the biggest hit, but they just kept coming. I would say more like a rolling train wreck.
I am not looking for any miracles and IMO all SP recovery will take is to get the PBT434 program started, which should be very soon. IF Kempler is to be believed, now may be the time to start accumulating. PBT434 looks like a very strong candidate and ticks all the boxes in the preclinical studies.
Expand
Is not looking good though.. 4 year delay in the program, no explanation why, and not even a peep if p1 will actually start this financial year as reported in last year's annual report. Or if it will be pushed back another 6 months again with no explanation.
Let's not forget the supposedly great pbt 512 has been buried before even being tested. And there has not been any mention of any new molecule from their reportedly massive pipeline which s going to bring about many new treatments.. almost nothing from tanzis dish, no more enlightenment about exactly what is going on with takeda ( or if that consultancy is already over)..
It's an absolutey barren wasteland at the moment.. And the SP reflects as much.