The following are some general comments that may help. This is why trials usually have pretty frequent visits, so that an outcome like that can be picked up early. Of course, it is also possible that the treatment might prove better, or at least as effective. Failure of a drug treatment is possible whether one is in a trial or not, because HIV treatment is still less than perfect. One advantage of a trial is that such problems can be piked up early and addressed promptly.
Most experts consider Tenofovir to be very promising.
Hope this helps. Note that my opinions are likely to be somewhat biased in favor of clinical trials, because much of my work is in that area. Best of luck. Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither The Body nor any sponsor is the publisher or speaker of posted visitors' questions or the experts' material.