GMHC criticises Vaxgen for obfuscation of trial results of its AIDS vaccine

Gay Men’s Health Crisis (GMHC), the USA’s oldest AIDS service organisation, has criticised VaxGen, the maker of the AIDS vaccine candidate, AIDSVAX, for obfuscation of its trial results. Despite showing no effect overall in protecting against infection with HIV, the company highlighted a subset of results that seemed to show efficacy in African-Americans and Asians.

GMHC said it looks forward to the day when HIV will be a preventable disease and is a strong supporter of AIDS vaccine research, including VaxGen’s research efforts. However, the conduct of vaccine research must be held to the highest standards of ethics and accuracy, as millions of lives depend on the results of these scientific studies, the organization said in a statement.

“Subset analyses are problematic in the best of cases. With small numbers of African-Americans and Asians in the trial and wide confidence intervals associated with the results, making any statements about efficacy in this subpopulation is grossly premature,” said Gregg Gonsalves, Director of Treatment and Prevention Advocacy at GMHC. VaxGen’s assertions of its vaccine’s efficacy among blacks are based on 13 infections in this population in a trial of more than 5,000 participants. The assertions about efficacy among Asians are based on only four HIV infections in the study.

GMHC is particularly worried that the ‘spin’ of these results will sow confusion in communities particularly at risk in the United States, specifically African-Americans. “VaxGen has not proven that this vaccine is effective among African-Americans or Asians, yet preliminary press reports are claiming that this may be the case,” said Ana Oliveira, GMHC’s Executive Director. GMHC is asking the company to clarify its statements on the subset analysis of African-Americans and Asians, particularly its claims of efficacy for this population, and is calling on the media to look more closely at the data before drawing any conclusions.

GMHC also has concerns that VaxGen’s interpretation of its results will also provide false hopes in Africa and Asia, where the rates of HIV infection are the highest in the world, and which will be the major market for AIDS vaccines. The organization said it is important to note that the vaccine in this study did not use strains of HIV prevalent in Africa and Asia. GMHC fears that claims of partial protection for African-Americans and Asians, by extension, could imply that Africans and Asians living outside the United States could see some protection from this vaccine. GMHC is urging the company not to overstate the promise of its product based on scant and inconclusive data.

VaxGen held a briefing to announce findings from clinical trials of the vaccine AIDSVAX regarding its ability to prevent people from becoming infected with HIV. AIDSVAX is the first AIDS vaccine to enter large-scale human clinical trials. The archived audiocast and accompanying slide presentation are available by clicking here. (NOTE: Access to audiocast requires free registration.) Also an Interview with Chris Collins, executive director, AIDS Vaccine Advocacy Coalition (video):
http://www.kaisernetwork.org/health_cast/hcast_index.cfm?display=detail&hc=789

Comment

These are obviously disappointing results, and in the attempt by Vaxgen to salvage something from this study it is unfortunate that this controversy over the presentation of racial differences has somewhat soured the significant logistic difficulties of running a large scale international vaccine study. Results from the Thailand study are expected in the next few months but this candidate has fallen far short of the reduced efficacy that the company hinted at over the last year, and the increases in stock value following each of those announcements has now fallen.