Dear MTN Family and Friends,
Earlier this year, at the Conference on Retroviruses and Opportunistic Infections in Montreal, we reported the results of HPTN 035, a Phase IIb study that was designed to assess the safety of 0.5% PRO 2000 gel and BufferGel and establish whether either product showed sufficient promise for further testing in a Phase III trial or for licensure. We reported that both gels were safe and PRO 2000 reduced the risk of HIV by 30 percent, a finding that, although encouraging, was not statistically significant. The test for statistical significance (p=0.10) suggested that there was a one in 10 likelihood that this moderately protective effect may actually have been due to chance. We looked to our colleagues conducting MDP 301, a Phase III study involving nearly 9,400 women, to give a more definitive answer about PRO 2000. As we have learned today, this larger trial has confirmed that PRO 2000 does not offer protection against HIV.
The MDP 301 research team is to be commended for their hard work, tenacious spirit and principled approach. The MDP team has demonstrated that large-scale, high-quality microbicide studies can be successfully executed in resource-poor settings. The women who took part in both MDP 301 and HPTN 035 deserve special recognition as well. If not for their dedication and commitment, these two studies could not have been completed.
Although we have now learned that PRO 2000 was not effective, specific details are not yet available. We can expect to learn much from a study of MDP 301’s size and caliber, information that well help the entire field work toward identifying safe and effective biomedical prevention strategies. But there is little question that this study marks the end to an era of investigation focused on the early generation, novel nonspecific microbicides. And the results raise little doubt that at this juncture, agents with specific action against HIV, such as antiretroviral drugs, offer the most hope.
Now it is with renewed purpose that we must work to realize the promise of antiretroviral-based prevention. The MTN’s portfolio of research on topical and oral antiretrovirals for prevention of HIV, including our flagship study, VOICE, which is now open at six clinical research sites in Africa, intends to do just that. These studies, and others, will help to assess whether antiretroviral drugs will be effective tools for curtailing the incidence of HIV, especially when used in combination with condoms, behavioral modification and other HIV prevention methods.
As this decade comes to a close, we hope that you will join us in thanking the communities and study participants who have partnered with our research teams to conduct these studies. We must not allow our disappointment in the outcome of MDP 301 to interfere with our current momentum and progress to apply drugs with known activity against HIV for prevention. We must hope that positive results are within our reach.
We wish you all the very best and look forward to continuing our work with you in the coming year.
Sincerely,
Sharon Hillier Ian McGowan