Exciting early results in gene editing contrast with issues around traditional gene therapies, including non-responders, safety and questions over the duration of efficacy.

The accepted commercial dynamics of a competitive indication in older patients can be disrupted by new entrants with improved profiles, lower priced biosimilar competition and (soon) Medicare price negotiations.

Some entrepreneurs combine talent and experience to produce multiple profitable exits for investors. But there are many who do not, and past success is indeed no guarantee of future performance.

More than one-quarter of biopharma or diagnostic start-ups that raised A rounds in the past 18 months had participation by one or more corporate venture arms. Plus news on recent financings by Esperion Therapeutics, XO1, PTC Therapeutics and Valeant.