**What is probability of technical and regulatory success (PTRS)?**

Probability of technical and regulatory success (PTRS) is the expected chance of success in a clinical trial or clinical program and successful regulatory approval to follow. It consists of two separate probabilities which are multiplied: the probability of technical success (PTS) which is the probability of success of the trial portion alone and probability of regulatory success (PRS) which is the probability of regulatory success alone. PTRS and its components are tabulated internally by pharma companies and used in making investment decisions. They are also updated over time as new facts emerge which might impact the probabilities of success including potential interim analysis data, other internal data, landscape shifts including readout of competitor trials, etc.