Silverback Therapeutics

The company's core product, the ImmunoTAC platform, was designed to deliver potent small molecules directly to diseased tissues, thereby minimizing systemic side effects. This was particularly aimed at pathways previously considered undruggable due to the toxicity of systemically administered small molecules. Silverback’s initial focus was on creating targeted immuno-oncology agents that activated myeloid cells within the tumor microenvironment to enhance cancer cell destruction. Their lead candidate, SBT6050, was a HER2-directed antibody conjugated to a TLR8 agonist, intended for patients with HER2-expressing solid tumors. Another program, SBT6290, targeted Nectin-4 for solid tumors, while SBT8230 was being developed for chronic hepatitis B by targeting ASGR1 in the liver.

Silverback Therapeutics achieved several significant milestones, including raising a total of $211 million in venture capital through multiple funding rounds. The company went public in December 2020, raising approximately $277.7 million in its initial public offering. In April 2020, veteran biotech executive Dr. Laura Shawver was appointed as CEO. However, in March 2022, the company announced disappointing clinical data for its lead oncology program and discontinued its development, leading to a significant restructuring. This culminated in a definitive merger agreement with ARS Pharmaceuticals in July 2022, which was completed in November 2022. The combined entity continued under the ARS Pharmaceuticals name, focusing on the commercialization of ARS's epinephrine nasal spray, Neffy. Following the merger, Silverback's independent operations ceased.