Pharmaceutical company Chiron on Tuesday reversed course and promised to continue funding a study into whether people with AIDS can combat HIV by strengthening their immune system, just three months after the company pulled its funding because the study was "too costly," the San Francisco Chronicle reports. In 1999, Chiron began funding a NIH study to determine if the anticancer drug interleukin-2, which Chiron developed, could suppress the onset of AIDS in HIV-positive patients. Current antiretroviral therapies work by suppressing the replication of HIV. According to Bruce Scharschmidt, Chiron clinical director, when the study was launched Chiron officials expected it would take six years and $75 million to enroll and study the effect of interleukin-2 on 1,400 patients. However, by last October Chiron had spent $60 million to recruit 1,950 patients, and company officials estimated the study would require four more years and an additional $100 million to complete as originally designed and halted their funding. But on Tuesday, Chiron President Craig Wheeler said, "We did not anticipate the amount of support this trial had in the HIV scientific community." Although Chiron officials and NIH scientists declined to say how much funding Chiron had agreed to provide, the Chronicle reports that Chiron will provide $5 million annually for the "next three to four years," considerably less than the $20 million per year for between four and five years the company originally pledged. Chiron's new financial commitment puts the onus on researchers, according to NIH scientist Cliff Lane. Researchers, who previously had been receiving approximately $5,000 per year for each volunteer, will now begin receiving about $2,000 annually for each participant. Lane said the study would "fall apart" if too many scientists drop out of the study because they cannot cover their costs, the Chronicle reports (Abate, San Francisco Chronicle, 1/15).