Sutro’s folate challenge to Immunogen hits a problem

When does disclosure of a best-in-class drug profile warrant a share selloff? When it is accompanied by questions about the way data were generated, apparently, along with concerns about lack of a therapeutic window.

A case in point is Sutro, which yesterday released an update from an ovarian cancer trial of its folate receptor α antibody-drug conjugate STRO-002. This caused Wells Fargo to trumpet STRO-002’s profile as “best-in-class” – the project is a challenger to Immunogen’s similarly acting mirvetuximab soravtansine, which recently scored in a similar setting – but today Sutro stock opened off 25%.