Trial Success Score (PTRS): The Odds a Drug Makes It
A trial success score, or PTRS (probability of technical and regulatory success), estimates the odds that a drug in development eventually gets approved. It starts from how often drugs at the same phase and in the same disease area have succeeded, then adjusts for details of the specific program. It gives you starting odds, not a prediction of the next result.
How a trial success score is built
The starting point is history. Across the industry, only 7.9% of drugs that entered Phase 1 from 2011 to 2020 were eventually approved, according to the BIO, Informa and QLS study. The odds rise with each phase passed, and they differ a lot by disease: cancer drugs had the lowest odds, blood disorders the highest.
Our score starts from those base rates for each phase and disease area, calibrated against past outcomes, then adjusts for details of the specific program. Each drug gets a percentage you can compare across the pipeline.
What the score tells you, and what it doesn't
Here is the honest part. In our study of 631 Phase 2 and Phase 3 readouts, a higher score did not reliably mean a better result on the day. A trial is one roll of the dice, and the score can't see the data inside it.
Where the score did help was the downside. In our 22,234 past stock-months, companies with a Phase 3 drug scored 50% or higher fell 30% or more over six months 10.4% of the time, against 24.4% for all biotechs. They did not rise 50% more often (12.6% against 13.3%). Part of that may simply be that higher-scored Phase 3 drugs tend to sit at larger, more mature companies; we haven't separated the two. Either way, the score is more useful for judging risk than for picking winners.
How to use it
- Compare the score with the price. A stock priced as if approval is certain, with a 40% score, carries a lot of risk.
- Read it next to the cash. A low score plus a short runway is the most dangerous mix.
- Watch it change. A score rises when a drug passes a phase and falls when a trial changes or slips.
See it live: The trial success score sits next to every upcoming readout, with phase, design, cash and runway.
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Frequently asked questions
Probability of technical and regulatory success: the estimated chance that a drug in development succeeds in its trials and is approved.
In the BIO, Informa and QLS study of 2011 to 2020, 7.9% of drugs that entered Phase 1 were eventually approved. Odds vary widely by disease area and rise as a drug passes each phase.
No. In our data a higher score did not reliably mean a better trial result. It did come with fewer big stock drops, so it is more useful for judging risk than for picking winners.
They describe the same idea. Different providers use different names and methods; ours starts from phase and disease-area base rates, calibrated against past outcomes, and adjusts for details of each program.
It moves when a drug advances to the next phase, when a trial's design or timeline changes, or when the drug receives an FDA designation.
Educational content only. Not financial advice. Past results don't predict future ones.