The latest science from the IAS Towards an HIV Cure Symposium

The 2016 edition of the International AIDS Society (IAS) Towards an HIV cure symposium was held in Africa for the first time, bringing together over 300 participants in Durban on 16–17 July 2016 to present and discuss the latest science in HIV cure and remission research. The symposium, chaired by Francoise Barre-Sinoussi, Steven Deeks and Sharon Lewin, included presentations by invited speakers (Table ​(Table1),1), roundtable discussion and oral and poster abstracts. Table 1. List of names and affiliations of invited speakers and panelists As the field of HIV cure and remission research grows and expands, the symposium covered virology, immunology, clinical studies and social sciences research, retaining its characteristic cross-disciplinary dialogue. As befits the location, an increasingly important proportion of participants, both researchers and community, were from sub-Saharan Africa. Out of the 65 invited speakers and panellists, 47% were women, echoing the positive trend of female researchers in HIV science. Over one and half days, the symposium was the place of discussion of the mechanisms of HIV persistence, and ways to reverse it, and the immunological responses to control and/or eliminate residual disease. Presentations included the latest scientific evidence on the clinical approaches towards cure and remission, as well as discussion on the perceptions and expectations of people living with HIV. The symposium coincided with the launch of the International AIDS Society 2016 global scientific strategy: towards an HIV cure 2016 [1], a blueprint of the current and future research directions to be addressed to accelerate a cure and/or remission for HIV. The keynote address was provided by Anthony Fauci who presented the challenges and opportunities in addressing HIV persistence [2]. Dr Fauci discussed how HIV persistence could potentially be addressed by two approaches: eradication of the reservoir (the classic ‘cure’) or the control of viral rebound by sustained virological remission. Among the strategies to address HIV persistence, Dr Fauci concentrated on discussing the control of viral rebound, defining it as ‘sustained virological remission’, indicating that the optimal starting point to achieve this status is a small reservoir and a competent immune system, which can be achieved by early initiation of combination antiretroviral therapy (cART). From that perspective, three possible strategies can be explored with the hope of achieving a state of sustained virological remission: natural immunity, therapeutic vaccines and passive transfer of HIV antibodies. In the context of passive transfer of HIV antibodies, Dr Fauci presented the data from infusions of 40 mg/kg of VRC01 (a first-generation neutralising monoclonal antibody) 3 days prior to ART interruption and 14 and 28 days following. All of the 10 patients rebounded following ART discontinuation; nevertheless some variability from the moment of treatment interruption to time to rebound was observed. The median rebound time was 39 days, compared to a median 11–28 days in the absence of VRC01 treatment as per the literature, suggesting a modest influence, albeit transient. Analysis showed that rebound did not occur because the level of VRC01 fell below what is known to be the protective level. An analysis of the virus pre-infusion, however, showed that some of the individuals already displayed pre-existing resistance to VRC01 explaining the lack of extended time to rebound. Overall these results show that multiple infusions of broadly neutralising HIV antibodies can be safe and well tolerated. To improve the length of sustained remission, further studies should explore antibodies with improved potency and breadth, antibodies with extended half-lives (which can be achieved relatively easily with minor modifications of the Fc region) and vector-based antibody production.