Hey, td,
Thanks for dropping by . . .
>>R788 vs. R406.
I believe R788 is actually a prodrug of R406, not a simple reformulation. A completely new molecule, as dosed (the same molecule after biotransformation to R406 in vivo).<<
Hmmmm. Rigel calls it an oral formulation in its PR. "R788, the oral solid dosage formulation of R406 . . . "
prnewswire.com
After Dacogen couldn't equal the survival benefit of Vidaza in MDS, prodrugs have started to make me nervous, and this recent entry from Derek Lowe's blog hasn't helped.
pipeline.corante.com
In the Dacogen case, it may have been the execution of the trials (dunno, maybe nobody does), and not the drugs, but still . . .
If it's quacking like a chicken, but Rigel's still calling it a duck, I'm going to start wondering about their credibility. But you're right, now that I recheck, there are instances in the literature, published by Rigel's own scientists, in which 788 is called a prodrug. For example, this other tox study:
ncbi.nlm.nih.gov
and this one:
Message 25136431
I'm more inclined to believe the scientists than the PR scribes on this issue.
Thanks for pointing this out; crossing my fingers and hoping it does better than Dacogen.
Cheers, Tuck |
