An FDA approval, particularly if it's the first one for a small-cap biotech, usually sends the stock soaring, but Seattle Genetics Inc. saw only a modest gain late Friday, despite a sooner-than-expected nod for Adcetris (brentuximab vedotin), its anti-CD30 antibody-drug conjugate for two types of lymphoma. (See BioWorld Today, Aug. 22, 2011.)