Biotechnology company ZymoGenetics Inc. said Monday data from early-stage clinical trial show its lupus treatment atacicept was safe and tolerable.

The drug, being developed with Swiss-based biotechnology company Serono, was tolerated across all dose levels in the Phase Ib study. Seattle-based ZymoGenetics said the companies hope to start a Phase II clinical trial before the end of the year.

The study involved 49 patients with systemic lupus erythematosus, the most common form of the immune system disorder. The key goal of the study was to test the drug for safety. Secondary goals measured biologic activity, or impact of the drug on disease symptoms. Results varied based on the dose.

The results were released at the American College of Rheumatology's annual meeting.

Shares of ZymoGenetics rose 57 cents, or 3.7 percent, to $16.06 on the Nasdaq in midday trading. The stock has traded between $15.02 and $25 over the last 52 weeks. American depositary shares of Serono fell 12 cents to $21.79 on the New York Stock Exchange.