We should see data on AT13387 this coming week. The next development is that Astx has identified it's lead compound for HVC...AT26893. This should be the next compound that they IND. Recently they published this:
Results: Compounds binding at the novel site show robust antiviral activity in the cell based genotype 1b replicon system with EC50 values in the 1-50nM range and 1000 fold cytotoxicity window. Long term selective pressure on the replicon at high compound concentrations resulted in mutations that map to the allosteric site, confirming the physiological relevance of the allosteric site. Unlike peptide derived active site inhibitors, this new class of compounds are low molecular weight (
I read the article and they do point out the Ocular problems. They compare it with the 120MG level of at11387. In the phase 1, they are dosing to see MTD. I don't know if the 120MG dose is the dose they are using in ph2. The less than 3% is very good for their drug. This ocular problems has halted other hsp90 compounds.
The other toxicity they don't discuss is the liver tox's. So we will have to see how they do with it. So far At11387 has had no liver problems. We will have to watch for these reports this week, the dose level they are using to really compare benefits.
I'm sure our competitor used statistics to their advantage. But it's good to be aware of these issues.
Waiting for the AT13387 results. Did you see the article this week on Synta in Seeking Alpha that talks about its Ganetespib drug? It compared Ganetspib drug to AT13387 for ocular toxicity and Ganetspib had a 3% toxicity vs a greater than 50% for AT13387. Are the SA writers being picky or is this a real concern?