ZymoGenetics Presents Positive Results From RECOTHROM Spray Study In Burn Patients

Seattle, WA - ZymoGenetics, Inc., recently presented results at the American Burn Association annual meeting from a clinical trial with RECOTHROM Thrombin, topical (Recombinant) administered by spray device to burn wound excision sites. The study evaluated the safety and immunogenicity of RECOTHROM for patients undergoing skin grafting for burns. Topical application of RECOTHROM using a pump spray device was well tolerated and demonstrated a similar safety profile and rate of antibody formation to that observed in the rThrombin Phase 3 clinical trial.

"Burn wound excision poses unique challenges to hemostasis," said David G. Greenhalgh, MD, FACS, University of California, Davis Medical Center, and primary study investigator. "The results of this study suggest that rThrombin may be a viable hemostatic alternative in burn patients."

"Results from the trial show that RECOTHROM was well-tolerated when sprayed onto excised burn wounds prior to skin graft placement, with a very low rate of antibody development consistent with data generated in our earlier clinical trials," said Nicole Onetto, M.D., Senior Vice President and Chief Medical Officer of ZymoGenetics.

The multiple site, single-arm, open-label clinical trial treated 72 subjects receiving partial- or full-thickness autologous sheet or mesh graft following burn injury. RECOTHROM was applied to newly excised wounds (graft recipient sites) using a ZymoGenetics-developed pump spray device. Adverse events, skin graft survival and formation of anti-RECOTHROM antibodies were measured at baseline and Day 29 after application of RECOTHROM.

There were no deaths or study drug discontinuations. Adverse events occurred in 63 (88%) of patients and were typical of adverse events seen following acute burn wound treatment. The most common adverse events were procedural pain (25 patients, 35%) and pruritis (itching) (18 patients, 25%). Most adverse events were minor in severity and judged to be unrelated to the study drug. Skin graft survival was consistent with the rate commonly observed in such procedures.¹

One patient had antibodies to RECOTHROM product at baseline (1.4%); another patient developed specific antibodies to RECOTHROM at Day 29 resulting in a low rate of antibody formation (1.6%). The antibodies detected did not neutralize human thrombin. These rates are similar to the low immunogenicity findings of the rThrombin Phase 3 pivotal clinical trial. RECOTHROM was well tolerated when administered with a pump spray device.

About RECOTHROM Thrombin, topical (Recombinant)
RECOTHROM is a recombinant form of human thrombin that is structurally and functionally similar to human thrombin. It is not derived from animal or human blood. With thrombin being used in more than 1 million surgeries each year in the United States, RECOTHROM gives surgeons the opportunity to provide their patients with a plasma-free thrombin alternative for surgical hemostasis. The production of recombinant proteins is not dependent on the availability of blood from animals or human donors and can be scaled-up to meet market demand.

RECOTHROM is indicated as an aid to hemostasis whenever oozing blood and minor bleeding from capillaries and small venules is accessible and control of bleeding by standard surgical techniques is ineffective or impractical. RECOTHROM may be used in conjunction with an absorbable gelatin sponge, USP.

IMPORTANT SAFETY INFORMATION
RECOTHROM is for topical use only and should not be injected directly into the circulatory system. There is a potential risk of thrombosis if the product is absorbed systemically. RECOTHROM should not be used for the treatment of massive or brisk arterial bleeding or in patients with known hypersensitivity to RECOTHROM, any components of RECOTHROM or hamster proteins.

No specific adverse events have been established as adverse reactions causally related to RECOTHROM administration. In a clinical study comparing RECOTHROM to bovine thrombin, adverse events were reported with similar frequency in both treatment groups. The most common event was incision site complication. Limited data (n = 6) are available on repeat exposure to RECOTHROM.

RECOTHROM is being commercialized in a global collaboration between ZymoGenetics and Bayer HealthCare which began in June 2007. ZymoGenetics retains US market rights and Bayer provides its trained surgical sales force to support the first three years of the US market launch. Bayer HealthCare acquired the rights to RECOTHROM in all markets outside the US. Bayer will be responsible for conducting any required clinical trials, securing regulatory approvals and commercializing the product in all countries outside the US.

¹ Foster K, et al. Efficacy and safety of a fibrin sealant for adherence of autologous skin grafts to burn wounds: results of a phase 3 clinical study. J Burn Care Res 2008;29(2):293-303).

SOURCE: ZymoGenetics, Inc.