A Californian biotechnology company tried to block publication of a major AIDS study that found that the experimental treatment the company was developing failed to improve the health of patients, the scientists conducting the research said.

The Immune Response company of Carlsbad, California, opposed publication of the study because it did not include a subanalysis it believed showed that the treatment boosted the immune systems of some patients.

But despite the objections of the company, the researchers, led by James Kahn of the University of California at San Francisco, submitted their results to JAMA, which published them.

The study, of 2527 patients at 77 hospitals, tested a therapeutic vaccine, marketed under the …