A rule of thumb for possible acquisition targets...assume there will not be an acquisition. That way, if it all falls through, you are able to move forward independently. This might explain Rothschild even if a deal is imminent.
References abound, but my personal experience with Trius, Cynapsus, Tigenix and others suggests this is a wise approach.
As regards RVX, the payout is likely quicker but probably smaller if fully acquired. I have no preference.