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Exhibit 99.1 SILVERBACK THERAPEUTICS Silverback Therapeutics Reports Second Quarter 2021 Financial Results and Provides Business Update SEATTLE - August 12 , 2021 – Silverback Therapeutics , Inc. ( Nasdaq : SBTX ) ( “ Silverback ” ) , a clinical - stage biopharmaceutical company leveraging its proprietary Immuno TAC technology platform to develop systemically delivered , tissue targeted therapeutics for the treatment of cancer , chronic viral infections , and other serious diseases , today reported financial results for the second quarter ended June 30 , 2021 and provided a business update . " The second quarter was notable for the significant progress we made across our entire pipeline of tissue - targeted therapies , with SBT6050 , our HER2- TLR8 ImmunoTAC leading the way with continued robust enrollment in our Phase 1 / 1b study , " said Laura Shawver , Ph.D. , chief executive officer of Silverback . " We are deeply appreciative of the patients , their families , and our clinical investigators who continue to contribute to the SBT6050-101 clinical trial , and we look forward to providing the first update of the clinical data at the ESMO conference in September . ” Recent Highlights SBT6050 ( HER2 - TL8 ImmunoTAC ) clinical abstract accepted for poster presentation at the European Society for Medical Oncology ( " ESMO " ) 2021 Annual Meeting . The presentation will provide an update on the monotherapy dose - escalation arm ( Part 1 ) and the pembrolizumab combination dose - escalation arm ( Part 3 ) of the SBT6050-101 Phase 1 / 1b study . Details of the upcoming ESMO poster presentation are as follows : Title : “ Interim results of a Phase 1 / 1b study of SBT6050 monotherapy and pembrolizumab combination in patients with advanced HER2- expressing or amplified solid tumors ” Klempner , S. , et al . Poster Number : 209P Session Date and Time : The ePoster will be released virtually on Thursday , September 16th at 8:30 AM Central European Summer Time / 2:30 AM Eastern Standard Time Announced a clinical supply agreement with Regeneron to evaluate SBT6050 in combination with Libtayo® ( cemiplimab ) , a PD - 1 inhibitor . Under the terms of the agreement , Silverback will expand the ongoing Phase 1 / 1b trial to evaluate the combination of SBT6050 and LibtayoⓇ in tumor - specific dose expansion cohorts , initially in HER2 - expressing non - small cell lung and gastric cancers . GLP toxicology study for SBT6290 ( Nectin4 - TLR8 ImmunoTAC ) is nearing completion , with IND filing on track for the fourth quarter of 2021. Dosing was initiated in the GLP toxicology study in the second quarter and cGMP manufacturing of the drug product for Phase 1 clinical supply has been completed , with release testing in progress . SBT8230 ( ASGR1 - TLR8 ImmunoTAC for chronic HBV ) continues to advance through preclinical development with early CMC activities initiated including selection of the clone and creation of a master cell bank . The GLP toxicology study is expected to commence in the first quarter of 2022 .