Alexion Pharmaceuticals

(ALXN) - Get Report

was among the worst-performing health-related stocks Wednesday, with shares tumbling 26% after the company said a study for its heart drug failed.

Alexion's Phase III trial of PRIMO-CABG2 with pexelizumab did show that the drug reduced the primary endpoint of heart attack or death within 30 days after coronary artery bypass graft surgery. However, the results didn't meet the threshold for statistical significance. The company's shares plunged $7.71 to $21.85.

Epix Pharmaceuticals

(EPIX) - Get Report

fell 15% after the company said the Food and Drug Administration is requiring another trial for its blood-pool contrast agent, Vasovist. The company received an approvable letter from the FDA, but the letter indicated that at least one additional clinical trial, and a re-read of images obtained in previously completed Phase III trials, are needed for approval. Epix said these studies would require a "substantial period of time" to complete. "In light of today's news, we have decided that we will have to reduce substantially our research efforts and our employment levels, which we will do in the first quarter of next year," said Interim CEO Michael Astrue in a statement. Epix shares were down 93 cents to $5.12.

Adams Respiratory

( ARXT) fell 7% after the specialty pharmaceutical company filed a registration statement for a share offering by certain stockholders. The holders are offering 5.65 million, with underwriters having the option to buy up to an additional 846,873 shares. Adams shares recently changed hands at $44.83, down $3.71.

Chindex International

(CHDX)

fell 6% after the company said it plans to close down its retail pharmacy distribution business. Chindex, which sells Western health care products and medical services in China, said it plans to concentrate on its core business of health care services and medical equipment distribution. The company said the retail products business hasn't contributed to earnings or cash flow. "Although we had an enviable national distribution platform, the margin structure of distributing on behalf of other companies did not allow for a sustainable business and we have found that developing and rolling out our own national brands required more cash than we had anticipated," said CEO Roberta Lipson in a statement. Chindex shares were down 47 cents to $7.28.

Shares of

Possis Medical

( POSS) fell nearly 5% after the company posted weaker-than-expected first-quarter results and cut its full-year revenue forecast. The medical device maker's first-quarter net income fell to $265,000, or 1 cent a share, from $2.2 million, or 11 cents a share, a year earlier. Excluding certain items, Possis posted a profit of $968,000, or 5 cents a share, compared with Thomson First Call's average analyst forecast of 10 cents a share. Possis' product sales slipped to $15.5 million from $17.5 million, missing the company's projected range of $15.9 million to $16.2 million. The company said it was hurt by Hurricanes Katrina and Rita, higher-than-expected sales force turnover and increased competition, among other things.

For fiscal 2006, Possis lowered its revenue forecast to $66 million to $70 million from its prior range of $69 million to $74 million. The company sees full-year earnings, before items, of 34 cents to 42 cents a share, below Wall Street's projection of 44 cents. Possis shares recently were down 50 cents to $11.25.