A former naval lieutenant with an undergraduate degree in physics and an MBA in finance, Brian Frenzel has decades of experience as a senior executive in the biotechnology sector. Since 2008, Brian Frenzel has served as president and chief executive officer of Tosk, Inc. in Mountain View, California. Tosk is one of very few pharmaceutical companies that uses fruit flies for drug discovery, despite the fact that the fruit fly has been a mainstay of biology research for over a century. Tosk's pipeline includes the mucositis prevention drug TK-90. It is the first drug discovered using fruit flies to demonstrate efficacy in human clinical studies. Mucositis is a painful gastrointestinal tract condition that is a common side effect of cancer therapies. Symptoms of mucositis include, ulcers of the mouth, stomach, intestinal tract, and anal canal; dry mouth; difficulty in swallowing and speaking; diarrhea; and blood in the stool. These symptoms typically first appear between one and two weeks in cancer patients following radiotherapy or chemotherapy treatment. Currently available therapies for mucositis provide only palliative relief. These include analgesics for pain and barrier sprays and numbing mouthwashes for the mouth and throat. Physicians may also recommend anti-ulcer medications and saliva substitutes. However, none of these methods are preventative, and relief is usually only partial and temporary.