Not every stage move is the same size

Five stages and unequal gaps

On the board, every molecule sits in one of five columns: phase 1, phase 2, phase 3, filed and approved. The columns are evenly spaced, but the odds of crossing each gap are not.

A widely cited industry analysis of development programmes from 2011 to 2020 put the chances of moving on roughly like this:

Multiplied together, only around 8 percent of drugs entering phase 1 reached approval. Rates vary by disease area; metabolic and endocrine drugs, which make up much of this board, have tended to do somewhat better than average.

What that means for reading our moves

• A phase 2 to phase 3 move is the biggest step on the board, even though it looks like one column.
• A filed to approved move is expected most of the time; a rejection at that point is the surprise.
• A deal does not move a molecule, but it often changes the odds that the next trial gets run quickly and well.

Why peptides are a special case

Peptides tend to hit their intended targets cleanly, which helps in early phases. Their hard problems come later: manufacturing at scale, devices for self-injection, and oral delivery. Two of the moves on the board, the delay for palopegteriparatide and the oral PCSK9 result for enlicitide, are really stories about those problems.

Position is a fact. Odds are an estimate. We try never to mix the two in a headline.