early and arrive at the detector prior to the parent ions. Castleman says the pattern of magic numbers observed for zirconium metcars is best accounted for by the multicage structure he and his coworkers have proposed. He compares the zirconium met-car data to those from tantalum-carbon clusters, which are known to increase in size by forming increasingly larger cubic clusters. A time-of-flight mass spectrum of tantalum-carbon clusters contains a pattern of magic numbers consistent with closed cubic packings, which is completely different from the pattern for zirconium met-cars. The met-car mass spectrometric data argue strongly against the possibility that met-cars possess a cubic structure, Castleman adds. Although a cubic structure with eight metals at the corners of the cube and 12 carbons connecting between them could explain the stability of Zr8C12 and the other basic met-cars, such an explanation is not compatible with the pattern seen for the larger met-cars. Whether the met-cars have enough stability to be isolated in bulk quantities remains to be seen. Castleman's group is working hard to produce macroscopic amounts of one of the new clusters. Rudy Baum
interleukin-2 wins FDA market clearance The Food & Drug Administration has granted marketing approval to Chiron's Proleukin, interleukin-2 (IL-2), for treating metastatic kidney cancer. Approval is a milestone in several respects. For one thing, IL-2 is the first drug approved specifically for treatment of kidney cancer, a generally fatal disease that afflicts about 10,000 people annually. IL-2 is not a cure and most patients in clinical trials experienced serious, even life-threatening, side effects, FDA notes, but the drug will provide some patients a treatment alternative. 'This treatment represents one of the first successful attempts to fight cancer by augmenting the function of the body's immune system/' says FDA Commissioner David A. Kessler. The approval is a milestone for the biotechnology industry and for the companies involved for additional reasons. IL-2 is the first interleukin to receive
FDA approval, out of about a dozen interleukins that have been discovered. Found by Frank Ruscetti while working in the lab of Robert Gallo at the National Institutes of Health, IL-2 is among the earliest substances explored by biotechnology. But it showed less clinical utility than initially anticipated, and lingered in the drug development and testing process. The approval also closes the arduous history of Cetus, acquired by Chiron in December 1991, and its genetically engineered IL-2 product. Cetus spent over $100 million and more than a decade focusing almost solely on IL-2 development. As the company's destiny became closely tied to IL-2's success or failure, a setback before FDA in July 1990—an advisory panel declined to recommend marketing approval—contributed to resignation of Cetus' chief executive, its reorganization, and its eventual sale. For Chiron, the approval helps validate its rather daring acquisition of Cetus. And since IL-2 is its first proprietary biopharmaceutical product, the clearance is a major step toward returning the firm to profitability. In the mid-1980s, IL-2 was hailed as a breakthrough anticancer agent with potential blockbuster status, but much of this enthusiasm later was dismissed as hype. In 1989, Cetus began marketing it for kidney cancer in Europe, where annual sales have reached only about $18 million. Initial U.S. sales are estimated at $30 million to $45 million a year. Chiron will have a seven-year exclusive market because of IL-2's orphan drug status for kidney cancer. Sales may expand as IL-2 is applied to other diseases, but so may competition from other firms. Clinical trials are under way on other cancers and AIDS. Ann Thayer
Russian chemical arms destruction stymied This week, the Geneva-based Conference on Disarmament reconvenes to continue negotiations on a global chemical weapons treaty. Several key sticking points remain. One point is the concerns the U.S. has raised for the past few years about the former Soviet Union's ability to meet deadlines for destroying chemical weapons, as specified in a 1990 bilateral U.S.-Soviet agreement.
Treblow elected to fill vacancy on ACS board Mordecai D. Treblow has been elected to the American Chemical Society Board of Directors as director from Region II, filling a vacancy caused by the death last year of Frederick Bailey. He will serve through 1995. Treblow won a runoff election against Nina I. McClelland by 2869 votes to 2623. The runoff was required because no candidate won a majority in the initial election in March involving four candidates. Treblow has been an ACS member since 1956, and a councilor for the Pittsburgh Section since 1982. At the ACS national level, he has served on the Committee on Divisional Activities, Committee on Professional Relations, and Professional Programs Planning & Coordination Committee. He was chairman of the Division of Professional Relations in 1991. In recent years, Treblow has been employed by Mead Imaging and Calgon. He is now a consultant.
These concerns, once vaguely stated, took on official coloration in testimony May 1 before the Senate Foreign Relations Committee by Stephen J. Ledogar, chief U.S. negotiator at the conference. He stated that the Russian Federation "cannot meet either the bilateral timetable or the 10-year deadline currently envisioned" in the global treaty under negotiation. "They can't get started. They can't even find a site. They have no ... destruction plan even on the drawing board," Ledogar said. Furthermore, he noted, the Russians have not offered additional data to allow the Geneva negotiators to build "a more realistic schedule" into the text of the global treaty. And this inadequate information prevents the 39-nation conference from considering changes to treaty language to accommodate Russia's request to convert some chemical weapons production facilities to civilian uses. The current treaty text calls for destruction of all production facilities. According to Ledogar, it will be difficult but still possible to reach agreement on a global treaty this year, if certain outstanding issues can be quickly resolved. Besides the destruction timetable, key unresolved issues include verification procedures for both challenge inspecMAY11,1992C&EN 5
