On September 13, 2021, Silverback Therapeutics issued a press release "announc[ing] that interim data from the dose-escalation portion of its Phase 1/1b clinical trial evaluating SBT6050 as a monotherapy and in combination with pembrolizumab in patients with advanced or metastatic HER2-expressing or amplified solid tumors will be presented at the upcoming European Society for Medical Oncology (ESMO) 2021 Congress from September 16-21, 2021" and advising that "[t]he accepted abstract. .. is now available on the ESMO website." Per the accepted abstract, while there was a manageable safety profile for Silverback Therapeutics' experimental therapy, SBT6050 yielded only one partial response among 14 HER2-positive solid tumors. On this news, Silverback Therapeutics' stock price fell by more than 23%, damaging investors. When the Silverback Therapeutics class action lawsuit was filed, the price of Silverback Therapeutics common stock continues to trade below the $21.00 per share IPO price.