You are reading information from a corporate press release. Obviously this is couched in “positive-speak.” But there is no detail.

What was the percentage of prostate cancer cells that were accurately identified? There is no information. What was the percentage of non-cancerous cells that were inaccurately targeted? There is no information.

Effective use of targeted therapeutic agents is dependent upon (at least) four things: the sensitivity and specificity of the molecule to bind to the correct target and the effectiveness and safety of the therapeutic capability of the agent to act on the targeted cells. None of this information is provided in the media release issued by this company, but without this information we have no real basis for determining whether this product will be effective on anyone.

This is far from being the first attempt to deliver targeted therapeutic agents to prostate cancer cells via PSMA. There is a big difference between the theoretical possibility and the effective execution of the idea. To date, despite multiple attempts, I am not aware that anyone has been able to execute this strategy with sufficient effectiveness to get even close to the idea of an approvable drug.

Now this doesn’t make the idea wrong. It simply means that it may be very difficult to make it work in the real world. If this company has solved the problem, great — but I shall reserve judgment until I see actual evidence of clinical effect in patients with well-defined disease. At least this is one more possibility to keep one’s eye on.