PTC, chasing BioMarin, posts phase 3 rare disease win but fails to silence skeptics

PTC Therapeutics’ phase 3 clinical trial in the rare inherited disorder phenylketonuria (PKU) has met its primary endpoint. And yet, the design of the study means analysts remain unsure about the strength of PTC’s hand and whether it can rival BioMarin’s Kuvan and live up to its $400 million peak sales forecast.