Horizon Pharma (NASDAQ: HZNP ) moved up 16.63% to $2.80 in the pre-market session. Horizon Pharma will receive approval of DUEXIS from the United Kingdom (UK) Medicines and Healthcare products Regulatory Agency (MHRA). Ameristar Casinos (NASDAQ: ASCA ) added 16.31% to $25.67 in the pre-market session. Pinnacle Entertainment (NYSE: