Study to Assess the Safety and Durability of Viral Control Beyond 24 Weeks of Analytical Treatment Interruption After the Administration of Candidate HIV-1 Vaccines DNA.HTI, MVA.HTI and ChAdOx1.HTI or Placebo in Early Treated HIV-1 Positive Individuals (ATI Extension of AELIX-002 Study)

The AELIX-002 trial has been conducted on a cohort of individuals who started cART within the first 6 months after the primary VIH infection, thus increasing the likelihood of observing a certain rate of post-treatment controls (PTC), regardless of treatment efficacy. Although the kinetics of HIV rebound should allow observing differences between placebo and control regarding the post treatment controls rate in case of efficacy of the IMPs, assessing the length and determinants of a post-intervention control (PIC) (i.e., associated with vaccination) beyond 24 weeks is crucial for developing a curative approach to HIV infection. In this regard, an extension of the ATI phase for those individuals with pVL less than 2,000 copies/mL after 24 weeks of ATI in the AELIX-002 offers an unique research opportunity to better understand relevant aspects of the mechanisms involved in the different phenotypes of a PIC and PTC.

This trial will enrol participants of the AELIX-002 clinical trial regardless of whether they received vaccines or placebo, who reach 24 weeks of ATI with pVL <2,000 cop/ml and are willing to remain off cART. After accepting participation, subjects will undergo a one-year extension [48 weeks] of ATI monitoring (total duration of ATI envisioned will be of 72 weeks [24 weeks in AELIX-002 study + 48 weeks in current study]), followed by 24 weeks of safety follow-up after cART is resumed.

The primary objective of this study is to assess the safety and durability of viral control after AELIX-002 clinical trial intervention beyond 6 months of ATI. Furthermore, the study will collect biological samples to be stored for further investigational studies.

Inclusion criteria

• Participants of the AELIX-002 clinical trial at week 24 of ATI:

• Willing to continue the ATI up to 1 year.
• With pVL <2,000 copies/ml at week 24 of ATI on the AELIX-002 study.
• CD4 count ≥350 cells/mm3 at week 24 of ATI on the AELIX-002study.
• Willing to comply with the measures to prevent HIV transmission and reinfection required by the protocol.
• Available for follow-up for the planned duration of the ATI period of this study.
• Willing to accept blood draws and collect stool at time points specified in the Schedule of Procedures.
• If heterosexually active female; using an effective method of contraception (hormonal contraception, intra-uterine device

(IUD), or anatomical sterility in self or partner1) during the ATI and until her pVL is <50 copies/ml after cART resumption.

• If heterosexually active male; using an effective method of contraception (anatomical sterility in self) or agree on the use of an effective method of contraception by his partner (hormonal contraception, intra-uterine device (IUD), or anatomical

sterility1) during the ATI and until his pVL is <50 copies/ml after cART resumption.

• Not willing to donate blood during the study.
• Participants who understand the information provided, in the opinion of the investigator.

Exclusion criteria

1- Pregnancy or breastfeeding.

• History or clinical manifestations of any physical or psychiatric disorder which could impair the subject's ability to complete the study.

• Any other current or prior therapy which, in the opinion of the investigators, would make the individual unsuitable for the study or influence the results of the study.

• Active hepatitis B or C at week 24 of ATI on the AELIX-002 study.

• Risk of HIV transmission (i.e. repeated STI during the AELIX-002 ATI period or reported unprotected anal sex).