 SEATTLE--BUSINESS WIRE--Silverback Therapeutics, Inc. Nasdaq: SBTX Silverback, a clinical-stage biopharmaceutical company leveraging its proprietary ImmunoTAC technology platform to develop systemically delivered, tissue targeted therapeutics for the treatment of cancer, chronic viral infections, and other serious diseases, today announced the closing of its previously announced initial public offering of 13,225,000 shares of its common stock, which includes 1,725,000 shares sold pursua 