CETUS PLA FILING FOR PROLEUKIN (IL-2) IN RENAL CANCER

CETUS PLA FILING FOR PROLEUKIN (IL-2) IN RENAL CANCER is the biotech company's first application for U.S. marketing approval. The product license application (PLA) was submitted to FDA the week of Nov. 28. "Because this is our first application for U.S. marketing approval of a new therapeutic product derived from biotechnology, it represents an important milestone in Cetus history," President Robert Fildes commented in a Dec. 5 press release. In October, FDA designated interleukin-2 (IL-2) an orphan product for metastatic renal cell carcinoma. Cetus noted in its release that currently there is no effective treatment of the disease - the majority of patients survive less than one year following diagnosis. The U.S. filing for the recombinant lymphokine comes about four years after Cetus began clinical investigation of Proleukin as an anticancer agent, and follows by seven months a registration application with the European Economic Community's Committee for Proprietary Medicinal Products by EuroCetus, the company's European subsidary. EuroCetus has also filed for approval in the Scandanavian countries. Cetus' work on interleukin-2 became the subject of considerable media attention in 1986 when preliminary results of clinical work by National Cancer Institute (NCI) researcher Stephen Rosenberg, MD, were published in the New England Journal of Medicine. In 1987, NCI made IL-2 more widely available by giving Group C status, a designation that allows distribution of the drug throughout NCI-funded clinical centers. Subsequently, FDA began treating Group C applications as Treatment INDs, allowing even broader distribution. At a recent conference in Amsterdam sponsored by EuroCetus, Rosenberg reported a 10% complete response rate and a 20% partial response rate in 23 evaluable renal cell carcinoma patients participating in an overall 175-patient trial of IL-2 combined with lymphokine-activated killer cells. A 10% complete response rate has also been observed in melanoma patients. Cetus said that it holds "12 U.S. patents and several European patents covering various forms of interleukin-2 and processes for their manufacture." The company has based its patent strategy on "muteins," or slightly altered forms of the naturally occurring molecule. However, the first U.S. patent for recombinant IL-2 issued to Ajinomoto, whose U.S. licensee is Roche ("The Pink Sheet" April 25, T&G-2). Immunex, the Seattle-based biotech firm, has assisted Roche in the development of IL-2. Under a 1981 agreement, Immunex conducted preclinical research with Roche that led to the molecular development of the product. Roche's relationship with Ajinomoto evolved from a working relationship between Immunex founders Christopher Henney and Steven Gillis and the Japanese company prior to the formation of Immunex. At a meeting with securities analysts this past fall, Immunex CEO Stephen Duzan reported that final patient data for Roche's IL-2 was expected to be available in the fourth quarter. Roche plans to file a PLA as soon thereafter as possible, Duzan indicated. While Roche has not announced the indications it will seek, Duzan noted that the best responses to date have been observed in melanoma and renal cell carcinoma ("The Pink Sheet" Sept. 26, p. 10).