Shares of Amylin Pharmaceuticals ( AMLN) were among the worst-performing health-related stocks Thursday, falling 11% after the biopharmaceutical company posted third-quarter results that were worse than Wall Street expectations. The company reported a loss of $69.5 million, or 65 cents a share, on sales of $25.9 million. Analysts surveyed by Thomson First Call projected a loss of 57 cents a share on sales of $30.7 million. A year ago, the company reported a loss of $34.1 million, or 36 cents a share, on sales of $13.4 million. The company posted a big jump in selling, general and administrative expenses during the most recent period. SG&A expenses amounted to $52.1 million, which was up considerably from last year's $15 million. Amylin attributed the surging costs to the commercialization of Byetta and Symlin. Shares were trading down $4.42 to $33.57. Express Scripts ( ESRX) rose 16% after the pharmacy-benefit manager posted better-than-anticipated third-quarter earnings and lifted its full-year earnings guidance. The company earned $101.7 million, or 68 cents a share, on sales of $3.85 billion. Excluding items, the company earned $100.2 million, or 67 cents a share, topping analysts' estimate of 61 cents a share. A year ago, Express Scripts posted adjusted earnings, which exclude items, of $77.4 million, or 50 cents a share. The company's sales rose to $3.85 billion from $3.77 billion a year ago, shy of analysts' expectation for sales of $3.99 billion. Looking ahead, Express Scripts now expects full-year adjusted earnings of $2.54 to $2.61 a share, up from its previous guidance of $2.37 to $2.42 a share. Analysts had forecast earnings of $2.40 a share. Express Scripts shares were up $10.14 to $72.21. Shares of PacifiCare Health Systems ( PHS) rose 1.3% after the company posted better-than-expected third-quarter results. The health insurer earned $118.1 million, or $1.21 a share, on sales of $3.77 billion. After stripping out one-time gains and losses during the quarter, the company would have earned $1.18 a share. Analysts were expecting earnings, before items, of $1.01 a share on sales of $3.67 billion. A year earlier, the company earned $88.2 million, or 94 cents a share, on sales of $3.11 billion.