 Silverback Therapeutics Inc NASDAQ: SBTX stock dropped to the lowest level since its IPO in December 2020 in reaction to interim data from SBT6050 Phase 11b trial for solid tumors. The trial in advanced or metastatic HER2-expressing or amplified solid cancer was designed to evaluate SBT6050 as a monotherapy and combined with Merck Co Incs NYSE: MRK Keytruda pembrolizumab. 