My Doctor asked me a few months ago if I would like to participate in the Smart study. I decied not to take part in the study and then a few weeks later I read that they stoped the study because the patients who stoped taking the drugs did worse than those who did not. Now yesterday they showed in the Swiss News a doctor from the univeristy in Geneva (Bernard Hirschel) saying that they just proved that it is safe to stop taking your HIV drugs and then start again when the CD4 count falls. What is true now?

Thank you for your post. Let me provide some background on these studies for other readers and then attempt to address your question.

The SMART study enrolled thousands of patients with the plan of following them for several years. Patients were told to either continue antiretroviral therapy or to stop therapy when their CD4 cells were greater than 350 cells/uL and then restart when they dropped to below 250 cells/uL. The study was prematurely stopped by a monitoring board of independent experts that were charged with assuring the safety of study subjects. This group found that for many of the outcomes assessed, such as disease progression, the people who stopped therapy did worse than those who did not. The results of the study were then presented earlier this year at a scientific meeting, although have yet published. Full details as to why the treatment discontinuation group did worse than the continuous therapy group is not yet completely known and further analyses are underway.

The study you refer to was presented at the same meeting earlier this year and was just published in a scientific journal in the last few weeks. This was a much smaller study with a somewhat different design. In this case they similarly assigned people to continue therapy or stop when CD4 cells were greater than 350 cells/uL. However, this study had the treatment discontinuation group subjects restart therapy when their CD4 cells declined to less than 350 cells/uL, rather than the 250 cells/uL threshold used in SMART. As you note, the latter study did not see major differences in the outcomes of the two groups with a potential benefit of the treatment interruption group having been less antiretroviral exposure which may allow for less overall toxicity.

Only further analyses of both studies will definitively answer the question as to why the outcomes were different. However, one obvious and potentially important difference relates to the threshold for restarting treatment. Until more information becomes available I would suggest to my patients that this type of strategy be avoided. Nevertheless, this does not mean that there are not certain situations where treatment discontinuation might be appropriate, and these need to be addressed on a case by case bases between a given patient and their expert provider.

I hope that helps. Best, Eric