BOSTON ( TheStreet) -- Here are some more top biotech stock trades for the second half of 2011. The biotech stock trades listed on the following pages encompass pending FDA drug approval decisions and clinical trial results -- all of which have the potential to produce significant stock-price volatility in the next six months. These biotech stock events/trades expected before 2011 finishes build on the list of 10 biotech stock trades that I compiled and published last week. Represented below are an additional five pending FDA drug approvals, four phase III clinical trials and five phase II clinical trials -- all of which should occur in the second half of the year. Targacept ( TRGT) The event: Phase III study of TC-5214 as add-on therapy for patients with major depressive disorder. The timelines: Top-line results from one or more of the four phase III studies expected in the fourth quarter. The stakes: Targacept partner AstraZeneca ( AZN) is conducting a large phase III study program for TC-5214 in major depressive disorder. TC-5214 is a potential blockbuster depression drug if the phase III studies are successful. Aveo Pharmaceuticals ( AVEO) The event: Phase III study of tivozanib in kidney cancer. The timeline: Top-line results expected in the fourth quarter. The stakes: Tivozanib, Aveo's lead drug, is being compared against Onyx Pharmaceuticals' ( ONXX) Nexavar in first-line, advanced renal cell carcinoma, or kidney cancer. The study is designed to show that tivozanib can extend the time before tumors regrow or patients die compared to Nexavar. Threshold Pharmaceuticals ( THLD) The event: Phase II study of TH-302 in pancreatic cancer The timeline: Top-line results expected in the fourth quarter. The stakes: After a previous pancreatic cancer drug failed, Threshold is back developing another drug known as TH-302. The phase II study compares TH-302 plus the chemotherapy drug gemcitabine against gemcitabine alone in patients with first-line pancreatic cancer. The study is designed to show that the addition of TH-302 to gemcitabine can prolong the time before tumors start to grow.