Given the severity of DMD, I'm not convinced that global regulatory agencies would be sufficiently concerned by the chemistry for GSK-2402968 to mandate long-term studies for Glaxo and not Sarepta. Nonetheless, this is a very difficult issue to parse from the outside. Until I get direct access to management, I'm tentatively standing by my original view: Glaxo's choice of a lengthy development pathway is a worry, although perhaps only a modest one. Regardless of what happens with Glaxo, Sarepta's 48-week follow-up data for eteplirsen are critical. If those results show an unambiguous correlation between expression of dystrophin and 6MWT, there is plenty of upside from current levels. One final note: I want to thank everyone who provides constructive feedback to my columns, whether or not we agree. Despite my reputation as a skeptic, I'm always willing to change my mind if the data suggest I'm wrong. Disclosure: Sadeghi has no positions in any of the stocks mentioned in this article. Follow Nathan Sadeghi-Nejad on Twitter.