CSL Behring has licensed global rights to Uniqure NV's late-stage hemophilia B gene therapy candidate, AMT-061, for $450 million up front, plus up to $1.6 billion in potential milestone payments and royalties. Uniqure positioned the deal as a boon for its broader gene therapies pipeline, anchored by a Huntington's disease (HD) program. But the move appeared to sour investors hoping for a rumored near-term M&A takeout, sending company shares (NASDAQ:QURE) falling 21.8% to $49.22 on June 25.