San Diego is the third largest center of biotechnology in the United States, a ranking obtained by counting the number of public biotech companies.

Moreover, more biotech companies are within the city limits of San Diego than any other city in the country.

A review of Biocom/San Diego membership information turns up 27 bioscience companies involved in cancer research or diagnostics, most with multiple studies under way. At least five of those companies have treatments in Phase III studies, typically the final testing before the U.S. Food and Drug Administration is asked to give its blessings to a commercial product release.

But it’s a lot harder to come up with a comparative ranking for San Diego’s role in fighting cancer. The region is one of the top centers in oncology research, but even those deeply involved in the field are hard-pressed to give any quantifiable numbers.

“I’ll be honest with you, I don’t think anybody’s done data,” says Guy Iannuzzi, a local biomedical industry veteran and president of Mentus, a San Diego-based life sciences public relations and marketing firm. “The surveys that are being done are conducted in a generic way. They use metrics like the numbers of companies in a place. They don’t break it down further,” by type of drug being developed.

Iannuzzi has tried to get such numbers from trade groups such as the Biotechnology Industry Organization and its local equivalent, Biocom/San Diego, without success.

Other surveys that focus on what kind of drugs are being developed don’t break the numbers down by geography. For example, a recent survey by medical writer Joseph F. Dooley found that more than 350 new medicines are under development to treat cancer, and cancer therapeutics already on the market get $8.8 billion in sales. But Dooley says he could not tell how many of these were being developed by San Diego-based companies.

Nevertheless, some measures of San Diego’s importance to the fight against cancer are available. One is financial: in the quarter ended Sept. 30, sales of Rituxan, discovered by San Diego’s Idec Pharmaceuticals, reached $270 million, compared to $205 million a year earlier. That’s nearly 12 percent of the revenue of all cancer drugs on the market today. (Idec got help developing Rituxan from Genentech of South San Francisco, which keeps about two-thirds of the revenue.)

San Diego also is a hotbed of cancer research breakthroughs:

• Rituxan is the first monoclonal antibody to treat cancer.
  
  
• Carlsbad’s Isis Pharmaceuticals is applying its gene-blocking antisense technology in clinical trials of anti-cancer drugs.
  
  
• Research institutions such as The Burnham Institute, the Salk Institute, UCSD and Scripps are staffed with scientists renowned for their cancer-related work.

To name a few names, Erkki Ruoslahti of Burnham is ranked one of the most highly cited scientists in research by the Philadelphia-based Institute for Scientific Information. Ruoslahti’s specialty is metastasis.

Sydney Brenner, newly minted Nobel laureate at the Salk Institute, championed using the nematode C. elegans as a research workhorse, leading to discoveries in apoptosis or programmed cell death, now intensively investigated for cancer therapeutics.

Kurt Wüthrich, a structural biology professor at The Scripps Institute, also was awarded a Nobel Prize in October for work that’s being used for cancer research. Wüthrich got the prize for using nuclear magnetic resonance to study large biological molecules. This technology is being used by Cyternex, a San Diego startup developing cancer therapies.

— Bradley J. Fikes