Skip to Content

ZymoGenetics Presents Interim IL-21 Phase 2 Results in Renal Cell Cancer

SEATTLE--(BUSINESS WIRE)--Oct. 22, 2008 - ZymoGenetics, Inc. (NASDAQ: ZGEN) presented interim results today from a Phase 2 clinical trial evaluating Interleukin 21 (IL-21) in combination with Nexavar(R) (sorafenib) tablets in patients with metastatic renal cell cancer. Outpatient therapy with IL-21 and Nexavar as a second or third-line therapy for metastatic renal cell cancer was associated with anti-tumor activity, with manageable side effects. Of subjects treated and assessed by independent review, 3 of 18 patients had a confirmed partial response, for an overall response rate of 17%. In addition, two partial responses have not yet been confirmed. The overall response rate and disease control rate observed with the combination treatment regimen appears to compare favorably to results obtained in separate studies with single-agent Nexavar. The data was presented at the EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics.

"We continue to see promising anti-tumor effects from the combination of IL-21 and Nexavar in patients with renal cell cancer," said Nicole Onetto, M.D., Senior Vice President and Chief Medical Officer of ZymoGenetics. "We look forward to final results, including progression-free survival data, in the first half of 2009."

IL-21 with Nexavar is being tested in the Phase 2 study in an outpatient setting to evaluate the safety, pharmacokinetics and anti-tumor efficacy of the combination using the maximum tolerated IL-21 dose determined in Phase 1 (30 mcg/kg). Study endpoints were overall response rate and progression-free survival. Subjects had previously received one or two targeted therapies for renal cell cancer but had disease progression.

Anti-tumor activity (including 3 confirmed PRs) was observed, with stable disease or partial or complete response at any time on study, in 89% or 16 of 18 patients evaluated by independent and investigator review. Seven (54%) of the 13 patients who completed 3 treatment courses had stable disease or better. Interim results suggest a potential additive effect of IL-21.

Most adverse events (AEs) were Grade 1 or 2 and consistent with the known toxicity of Nexavar and IL-21 when administered as single agents. Serious AEs that were considered possibly related to IL-21 occurred in 6 subjects and included acute renal failure; rash and dehydration; coagulopathy, metabolic acidosis, and neutropenia; dyspnea; and acute hemolytic anemia.


The poster is available on the ZymoGenetics website at:

Renal Cell Cancer

Each year in the U.S., there are an estimated 51,000 new cases of renal cell carcinoma. It is estimated that renal cell carcinoma results in approximately 13,000 deaths per year in the U.S. Despite the positive impact of new treatments such as tyrosine kinase inhibitors and mTor inhibitors on the outcome for metastatic renal cell cancer, complete responses are rare and long-term survival remains poor.

About IL-21

IL-21 has potent biological activity in regulating key classes of immune cells, including cytotoxic T cells and natural killer cells. These cell types play important roles in eliminating malignant and infected cells. Results from clinical trials to date have shown that IL-21 administration was well tolerated in an outpatient setting, and reductions in tumor size, including clinical responses per RECIST criteria, have been observed in several patients. ZymoGenetics is developing IL-21 for the treatment of renal cell carcinoma and metastatic melanoma and has commercialization rights for IL-21 in North America.

About ZymoGenetics

ZymoGenetics discovers and develops novel protein therapeutics that are based on the company's research and biological insights into key disease pathways. The Company developed and markets RECOTHROM(R) Thrombin, topical (Recombinant). Other product candidates span a wide array of clinical opportunities that include cancer, autoimmune and viral diseases. ZymoGenetics intends to commercialize product candidates through internal development, collaborations with partners, and out-licensing of patents from its extensive patent portfolio. For further information, visit

This press release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are based on the current intent and expectations of the management of ZymoGenetics. These statements are not guarantees of future performance and involve risks and uncertainties that are difficult to predict. ZymoGenetics' actual results and the timing and outcome of events may differ materially from those expressed in or implied by the forward-looking statements because of risks associated with our unproven product sales and marketing abilities, discovery strategy, preclinical and clinical development, strategic partnering, regulatory oversight, intellectual property claims and litigation and other risks detailed in the company's public filings with the Securities and Exchange Commission, including the company's Annual Report on Form 10-K for the year ended December 31, 2007. Except as required by law, ZymoGenetics undertakes no obligation to update any forward-looking or other statements in this press release, whether as a result of new information, future events or otherwise. ###

Nexavar(R) (sorafenib) tablets is a registered trademark of Bayer HealthCare Pharmaceuticals, Inc.


ZymoGenetics, Inc.
Susan W. Specht, 206-442-6592
Director, Corporate Communications
Michael Fitzpatrick, 206-442-6702
Associate Director, Corporate Communications


Posted: October 2008