Not really true. SNTA spent a good bit of their JMP webcast talking about this exact issue for those who care to listen.
I would suggest that this is a little bit of an overstatement - what Safi talked about was the fact that he was encouraged by the fact that the squamous vs adeno effects are similar to VEGF inhibitors and that was a good sign (as in lending more credibility to the drug). But I don't think he in any way intimated that it was the only MOA.
And separately, as an example of that, I would point out that so far as I know the VEGF inhibitors don't have any special effect on ALK+ tumors.
PS I thought the most interesting thing in his presentation was the comment that the progression in the placebo arm was largely driven by new mets. In contrast the progression as seen in the G arm was rarely driven by new mets. (i.e. consistent with the overall OS results). I've always wondered why this data isn't more commonly discussed - e.g. I thought it would be interesting data from the Provenge trials.