GENEVA, Switzerland, December 13 /PRNewswire/ --

- Trial Will Evaluate Safety and Efficacy of Atacicept in Lupus Nephritis and is Intended to Support Marketing Authorizations

Merck Serono, a division of Merck KGaA, and its partner ZymoGenetics, Inc. (NASDAQ: ZGEN) announced today the initiation of a Phase II/III clinical trial of atacicept in lupus nephritis, a severe form of systemic lupus erythematosus (SLE). The kidneys are affected in at least 30% of the estimated 1.5 million people suffering from SLE worldwide. This study will evaluate the efficacy and safety of atacicept for the treatment of patients with active lupus nephritis.

The trial is being conducted under a Special Protocol Assessment (SPA) agreement with the U.S. Food and Drug Administration (FDA) and is intended to support worldwide applications for marketing authorization.

"Lupus nephritis patients need better treatment options to help them maintain kidney function and avoid kidney failure," said Nicole Onetto, M.D., Senior Vice President and Chief Medical Officer of ZymoGenetics. "Based on its mechanism of action and our early clinical data in lupus, we believe that atacicept has the potential to reduce disease symptoms and may help patients improve kidney function."

Anton Hoos, M.D., Merck Serono's Head of Global Development, added: "This study forms part of our ongoing development program with atacicept in autoimmune and inflammatory diseases. It underscores Merck Serono's strong commitment to offering innovative treatment options to patients and their doctors in indications with unmet medical needs."

The one-year (52-week), randomized, double-blind, placebo-controlled Phase II/III clinical trial will enroll approximately 200 patients and will be conducted at approximately 80 sites in North America, Europe, Latin America, and Asia.

The objective of the study is to evaluate the efficacy and safety of atacicept in patients with active lupus nephritis who are also receiving immunosuppressive therapy with mycophenolate mofetil (MMF) and corticosteroids. To be eligible to enroll in the trial, patients must have active lupus nephritis at the time of screening. The primary endpoint of the trial is the improvement in patients' renal function from baseline to week 52.

About atacicept

Merck Serono and ZymoGenetics are developing atacicept (formerly referred to as TACI-Ig) as a potential treatment of autoimmune diseases, such as systemic lupus erythematosus (SLE), lupus nephritis (LN), rheumatoid arthritis and multiple sclerosis, as well as B-cell malignancies. Atacicept, a recombinant fusion protein, contains the soluble TACI receptor that binds to the cytokines BLyS and APRIL. These cytokines are members of the tumor necrosis factor family that promote B-cell survival and autoantibody production associated with certain autoimmune diseases such as systemic lupus erythematosus. Current data indicates that levels of BLyS and APRIL are elevated in patients with rheumatoid arthritis, SLE and B-cell malignancies. Atacicept has been shown to affect several stages of B-cell development and may inhibit the survival of cells responsible for making antibodies.

About lupus nephritis

Lupus nephritis is a complication of systemic lupus erythematosus (SLE) and is characterized by inflammation of the kidneys. Patients with lupus nephritis typically have damage to the glomeruli and progressive loss of kidney function. In the United States, for example, SLE affects 1 person in 2,000, with higher rates among women and among individuals with African, Asian, and Hispanic genetic heritage. Published studies estimate that clinically significant renal involvement occurs in at least 30% of those with SLE.

About ZymoGenetics

ZymoGenetics creates novel protein drugs with the potential to significantly help patients fight their diseases. The Company is developing a diverse pipeline of product candidates that are moving into and through clinical development. These candidates span a wide array of clinical opportunities that include bleeding, autoimmune diseases and cancer. ZymoGenetics intends to commercialize these product candidates through internal development, collaborations with partners, and out-licensing of patents from its extensive patent portfolio.

For further information, visit

About Merck Serono

Merck Serono, the new division for innovative small molecules and biopharmaceuticals of Merck, was established following the acquisition of Serono and the integration of its business with the former Merck Ethicals division. Headquartered in Geneva, Switzerland, Merck Serono discovers, develops, produces and commercializes innovative products to help patients with diseases with unmet needs. Our North American business operates in the United States and Canada under EMD Serono.

Merck Serono has leading brands serving patients with cancer (Erbitux(R)), multiple sclerosis (Rebif(R)), infertility (Gonal-f(R)), metabolic and cardiometabolic disorders (Glucophage(R), Concor(R), Saizen(R), Serostim(R)), as well as psoriasis (Raptiva(R)). With an annual R&D investment of EUR 1bn, we are committed to growing our business in specialist-focused therapeutic areas such as Neurodegenerative Diseases and Oncology, as well as new therapeutic areas potentially arising out of our research and development in Autoimmune and Inflammatory Diseases.

About Merck

Merck is a global pharmaceutical and chemical company with sales of EUR 6.3 billion in 2006, a history that began in 1668, and a future shaped by 30,962 employees in 61 countries. Its success is characterized by innovations from entrepreneurial employees. Merck's operating activities come under the umbrella of Merck KGaA, in which the Merck family holds an approximately 70% interest and free shareholders own the remaining approximately 30%. In 1917 the U.S. subsidiary Merck & Co. was expropriated and has been an independent company ever since.

For more information, please visit or

Contacts: Merck Serono, 9 Chemin des Mines, 1202, Geneva, Switzerland, Media Relations, Phone: +41-22-414-36-00