Shares of

Trimeris

( TRMS) were among the best-performing health-related stocks Wednesday, rising 13% after the company posted a second-quarter loss that was narrower than expected.

The biotech company reported a loss of $3.1 million, or 14 cents a share. Analysts polled by Thomson First Call were expecting a loss of 17 cents a share. Sales of anti-HIV drug Fuzeon came in at $53.9 million, up 48% from last year's total of $36.4 million.

Roche

, Trimeris' collaborative partner, records all sales of Fuzeon. A year ago, the company recorded a loss of $16.2 million, or 75 cents a share. Shares were trading up $1.43 to $12.75.

Medicines Co.

(MDCO) - Get Report

fell sharply in heavy volume Wednesday after reporting second-quarter earnings that were roughly half the year-ago amount. Despite a 24% rise in revenue, the company posted a profit of $1.3 million, or 2 cents a share, down from $2.8 million, or 6 cents a share, last year. Analysts were forecasting earnings of 7 cents a share. The stock was recently off $2.43, or 10%, to $21.90 on about 14 times normal volume.

Shares of

Align Technology

(ALGN) - Get Report

fell 11% after the maker of teeth-straightening products posted second-quarter earnings that fell a penny shy of estimates. The company reported earnings of $538,000, or 1 cent a share, on sales of $53.9 million. Analysts were expecting earnings of 2 cents a share on higher sales of $54.5 million. A year ago, the company posted pro forma earnings of $5.6 million, or 9 cents a share, on sales of $44.2 million. Shares were trading down 74 cents to $6.31.

Advanced Medical Optics

(EYE) - Get Report

traded actively after the company posted second-quarter earnings that matched expectations. The eye surgery products company reported a loss of $438.1 million, or $9.53 a share, on sales of $227.1 million. Excluding several items, however, the company would have earned 37 cents a share.

Analysts were expecting earnings of 37 cents a share on sales of $220.2 million. Looking ahead, Advanced Medical backed its 2005 adjusted earnings guidance of $1.65 to $1.75 a share on sales of $920 million to $930 million. Analysts are expecting earnings of $1.72 a share on sales of $932.4 million. For all of 2006, the company expects adjusted earnings of $2.20 to $2.30 a share on sales of $1.02 billion to $1.04 billion. Analysts are expecting earnings of $2.24 a share on sales of $1.05 billion. Shares were recently trading down 5 cents to $40.77.

Shares of

IMS Health

( RX), which recently agreed to be acquired by Dutch company

VNU

, traded actively Wednesday after the company posted second-quarter earnings that topped forecasts.

The company earned $93.2 million, or 41 cents a share, on sales of $433.3 million. Excluding charges and a tax benefit, the company would have earned $77.8 million, or 34 cents a share. Analysts were expecting earnings of 31 cents a share on sales of $421.9 million. A year ago, the company posted pro forma earnings of $69.5 million, or 29 cents a share, on sales of $379.6 million. Shares were trading down 21 cents to $26.94 on volume of about 4.1 million shares, or more than two times normal volume.

Other health-care volume movers included

Amgen

(AMGN) - Get Report

, up $9.39 to $79.91;

Pfizer

(PFE) - Get Report

, down 24 cents to $27.14;

Millennium Pharmaceuticals

( MLNM), up 63 cents to $10.51;

Gilead Sciences

(GILD) - Get Report

, up 45 cents to $47.05;

StemCells

(STEM)

, down 27 cents to $5.15;

Elan

(ELN)

, up 10 cents to $8.02;

UnitedHealth Group

(UNH) - Get Report

, down 66 cents to $49.92;

Johnson & Johnson

(JNJ) - Get Report

, down 45 cents to $64.57;

Schering-Plough

( SGP), up 12 cents to $20.10; and

Genentech

( DNA), up 84 cents to $89.09.