Washington Editor

Omrix Biopharmaceuticals Inc. soon plans to file for FDA approval of its topical human thrombin product after achieving positive Phase III results in a non-inferiority trial.

Importantly, the study demonstrated human thrombin's "equivalent efficacy" to its bovine counterpart, said Peter Johnson at the University of North Carolina School of Medicine during a conference call. He added that the human product would be a safer alternative to the animal-derived thrombin for reasons related to immunogenicity and other concerns.

The company, of New York, plans to file its biologics license application by Nov. 15. President and CEO Robert Taub said he expects FDA approval next year, followed by a launch soon after. Marketing would be handled through Omrix's partnership with Ethicon Inc., a division of New Brunswick, N.J.-based Johnson and Johnson, and the partners have high hopes for human thrombin and other biosurgical products they're collaboratively developing.

Hemostats, Taub said, are believed to represent "the fastest-growing" segment of the surgical sealant market.

In the pivotal trial, human thrombin produced hemostasis in general surgery procedures at the same rate as bovine thrombin, the standard product in that space that has been used for decades and in recent years has increased to more than 1 million applications per year in the U.S., Johnson said. Specifically, the study met its primary endpoint, with both human and bovine thrombin achieving hemostasis 97.4 percent of the time within 10 minutes of product application in subjects undergoing elective surgical procedures.

Among the surgical procedures evaluated - cardiovascular surgery, neurological spine procedures, general surgery or post-traumatic procedures - the incidence of hemostasis within 10 minutes was similar between treatment groups.

Secondary endpoints also were met, with human thrombin achieving hemostasis better at three and six minutes compared to bovine thrombin. Specifically, human thrombin produced that desired effect within three minutes 73.2 percent of the time, compared to 72.4 percent of the time with the bovine product, and 94.8 percent of the time within six minutes, compared to 92.8 percent.

In terms of safety, the incidence and severity of adverse events observed in the study were similar between treatment groups.

The most common related adverse events occurring in more than 1 percent of patients treated with both thrombin products included hypotension, pruritis and procedural complications, adverse events that Johnson said were "as expected" in patients undergoing the types of surgeries evaluated in the study.

While the products proved fairly similar in terms of their efficacy and safety profiles, Omrix is suggesting a more favorable profile for its clotting agent compared to bovine thrombin. For example, human thrombin, which does not need to be reconstituted prior to use, can be prepared for application in one minute, while bovine thrombin requires reconstitution.

The double-blind trial, which was designed to support broad product labeling for the use of topical human thrombin as an aid to control bleeding during surgery, randomized 305 patients to receive either of the two thrombin products at 22 sites in the U.S. The two arms were divided equally, and 93 subjects were in cardiovascular surgery, 121 were having spine procedures and 91 were in general surgery or post-traumatic procedures.

Topical human thrombin, a new, human plasma-derived concentrate of stabilized thrombin formulated with calcium chloride, is one of two components of Evicel, an FDA-approved fibrin sealant that formerly was called Crosseal. A liquid product that is sprayed or dripped onto a surgical site, it has no material of animal origin, meaning that it might be less immunogenic than products derived from animal sources.

Marketed through the Ethicon partnership, it's also sold worldwide under the name Quixil. Given the positive track record with that product, "we have a good basis for our upcoming interactions with the FDA," Taub said.

In addition to its plans for human thrombin, additional biosurgical efforts at Omrix are focused on a next-generation Evicel product, a new biological hemostat dressing and a flowable thrombin to be developed as a device combination. Such work falls under the agreement with Ethicon, which is paying most of the development costs while Omrix stands to receive a percentage of revenues from sales.

On Monday, its shares (NASDAQ:OMRI) lost $2.91, or 14.3 percent, to close at $17.45.

FDA Wants More Aranesp Data

In other late-stage product development news, Amgen Inc. said the FDA issued an approvable letter for the use of Aranesp (darbepoetin alfa) once every two weeks and once monthly dosing regimens for chronic kidney disease (CKD) patients with anemia not on dialysis.

But the agency requested additional data for the once-monthly dosing regimen, including an additional clinical study. The FDA also requested additional label language and clarification of submitted data for the de novo once-every-two-week dosing regimen.

Aranesp has been approved by the FDA for five years as a treatment of anemia associated with CKD in patients on and not on dialysis. In 2002, it was approved for chemotherapy-induced anemia in patients with nonmyeloid malignancies. The company, of Thousand Oaks, Calif., submitted a biologics license supplement to the FDA late last year for those Aranesp dosing regimens.

On Monday, its shares (NASDAQ:AMGN) fell 79 cents to $72.43.