RE:The FDA-BTD approval process...
Agree the FDA wants to review this newer treatment thouroghly, They don't need a flip flop scenario where they green light it and then have to retract. However, PDT has been around for decades. What's different is Ruvidar. Considering the success to date i wouldn't be surprised if Theralase is granted AA along with the BTD.
The waiting is certainly annoying but someone pointed out a while back that even big pharma can take up to a year for their new drugs to receive BTD.
I don't think Keytruda generates a whole lot of sales from treating bladder cancer. And while Ruvidar poses a threat down the road to other cancers treatments Keytruda patents expire in a few years anyways so if Merck wants a patent protected technology whether it's Ruthenium or Osmium look no further....