Brian Frenzel is the president and CEO of Tosk, Inc. Under his leadership, the company develops drugs designed to treat cancer with reduced side effects. Additionally, Brian Frenzel is a senior advisor and a former director at SanBio, Inc. SanBio is a medical research company focused on developing regenerative therapies for neurodegenerative diseases. In March 2021, SanBio presented the phase 2 trial results of a STEMTRA study at the 44th Annual Meeting of the Japan Society of Neurotraumatology. Phase 2 refers to the stage in which drugs are tested for efficacy and side effects. The STEMTRA study explores the therapeutic effect of SB623 in cases of traumatic brain injury (TBI). SB623 is a form of stem cell treatment consisting of genetically modified mesenchymal cells obtained from adult bone marrow. The study evaluated the effectiveness of SB623 in improving motor function in TBI patients. The phase 2 trial results showed that motor function in patients who received SB623 was significantly improved compared to the control group. Furthermore, long-term assessment of SB623 effects demonstrated the drug was safe.