Versartis, Inc. (VSAR)

[longx]

why not just increase dosage?

Analyst at Cantor Fitzgerald explained that it's because new dosage will require additional trials, ultimately this will delay commercialization and potentially diminish the company’s advantage over competitor Ascendis.

A copy of the original text:
"Although we believe these pivotal data are insufficient to support approval, we believe that optimizing for a higher dose administered more frequently could achieve the range of activity to demonstrate non-inferiority,” analyst Elemer Piros wrote in a note.

An additional trial would be needed, ultimately delaying commercialization and “potentially diminish[ing] the company’s advantage over competitor Ascendis Pharma A/S"
https://www.benzinga.com/analyst-ratings/analyst-color/17/09/10089620/versartis-somavaratan-still-has-a-path-forward-cantor-r