SanFranscisco - You are correct about a bunch of rough guesses.

I could not find the Zacks report that I believe that 53% number came from. The one I was looking for came out in 2015 or 2016. The updated reports from John Vandermosten at Zacks dated 4/1/2019 gives  a 64% probability of ABL sales for the indications in the BoM trial. This 64% probability is the same in the Zacks report dated 12/28/2018. These 2 Zacks updates are found in our Link Library.

Having gone down this rabbit hole I found a couple of interesting pieces of info. Sorry I don't know how to cut and paste links with this tablet I'm using.

From our Link Library - Beacon Securities RVX report by Dr David Kideckel 11/15/2017 Risks, pages 21 in the chart of Distribution of lead product stages 54%. That chart is about the; Breakdown of healthcare M&A by development stage of lead asset, Source Thompson Reuters.

From the FDA site % of drugs that move from one stage to the next.

P1  70% move to  P2

P2  30% move to  P3

P3  25% to 30% move to the next stage

No % was given for the drugs that made it past P3 to the drugstore shelf. It was interesting that different websites for drug developers, organizations and associations varied in the length of time in each stage of the trials and % chance of success.

An Interesting read as well was; Regulatory Requirements for the Drug Approval Process in US, Europe and India, ISSN:0975-1459 found at www.jpsr.pharmainfo.in    There was a whole bunch that came after that link but you can Google the earlier part to find that report. 

Neadless to say rough guesses is close. There was discussion on this board about how Zacks came up with that, about 53% when the initial Zacks report first came out.

tada