Assistant Managing Editor

Only a day after reporting positive interim results from a Phase II study of its Fibrin Pad product in mild to moderate bleeding, Omrix Biopharmaceuticals Inc. said the study has been suspended to investigate an incident of postoperative bleeding.

Shares of the New York-based firm (NASDAQ:OMRI) plunged 34.5 percent, losing $6.14 Thursday to close at $11.67.

Interim analysis from the U.S. Phase II study, conducted after 90 patients were randomized 2-to-1 to receive Omrix's Fibrin Pad or Surgicel (Johnson & Johnson), showed that the Fibrin Pad was superior to Surgicel in controlling mild to moderate soft tissue bleeding during abdominal, retroperitoneal, pelvic and thoracic surgery.

The trial was designed to measure the proportion of subjects achieving hemostatic success at four minutes after randomization without requiring additional treatment during a subsequent six-minute observation period.

The trial was to continue enrolling patients until at least 100 subjects had been treated with Fibrin Pad, and prior to announcing the trial suspension, Omrix said it had expected to complete that enrollment by the end of this year or early next year.

The company has not disclosed any details of the suspension at this time, and representatives of Omrix could not be reached for comment.

The Fibrin Pad is designed to use the company's aprotinin-free fibrin sealant technology, the same technology that helped create Evicel, a liquid fibrin sealant that gained FDA approval as an adjunct to hemostasis in patients undergoing surgery when control of bleeding by standard surgical technique is neither effective nor practical.

As a next-generation, absorbable biosurgical product, the Fibrin Pad comprises a flexible biodegradable matrix that's coated with human fibrinogen and human thrombin and is designed to help form instant clots for rapid control of bleeding and for possible use on active bleeding sites.

It was not clear from the company's release when the incident of postoperative bleeding occurred in the U.S. Phase II trial, though analyst Jonathan Aschoff, of Brean Murray Carret & Co., wrote in a research note that it occurred after the 90th patient was enrolled and, therefore, was not included in the interim analysis.

Omrix also reported data from a separate ongoing Phase II trial in Israel that is designed to test Fibrin Pad in severe bleeding when the product is applied primarily on the bleeding site. And in that study, four patients have been treated to date with Fibrin Pad, one of whom experienced postoperative bleeding.

"While the detailed reason for this serious adverse event is still under investigation, the fact that it occurred in two patients treated with the Fibrin Pad so far" raises questions as to the product's safety profile, Aschoff wrote, adding that there likely would be some delay in the program, for which he previously had projected a mid-2010 market launch.

Omrix also has submitted an application to UK regulatory authorities to begin a pivotal study of Fibrin Pad in soft tissue severe bleeding when applied adjunctively to the standard of care. That application is under review.

In addition to Evicel, Omrix markets Evithrom (topical human thrombin), a blood-clotting protein - using the same thrombin component as Evicel - for controlling bleeding during surgery. Evithrom gained approval in 2007 and is distributed by a division of Somerville, N.J.-based Ethicon Inc. (See BioWorld Today, Aug. 29, 2007.)

Outside of biosurgery, the company is developing several immunotherapy products, including intravenous immunoglobulin (IVIG) for immune deficiency and autoimmune diseases, as well as other antibody-based products targeting hepatitis B, West Nile virus and smallpox vaccine-related complications.

Omrix recorded total revenue of $19.2 million for the second quarter - $18.2 million of that came from product sales - and posted a net income of $3 million, or 17 cents per share. As of June 30, the firm had a cash position of $83.1 million.