Suspended

A Randomized, Multicenter Trial to Determine Whether Induction Therapy Followed by Treatment Interruption is Superior to Induction Therapy Alone in the Treatment of Primary HIV Infection (PHI): The Structured Treatment Interruption (STI) Study

0 criteria met from your profileSee at a glance how your profile meets each eligibility criteria.
What is being tested

Structured treatment interruption

+ Antiretroviral regimen
Behavioral
Drug
Who is being recruted

Blood-Borne Infections
+15

+ Urogenital Diseases
+ Genital Diseases
Over 18 Years
See all eligibility criteria
How is the trial designed

Treatment Study

Interventional
See protocol details

Summary

Principal SponsorNational Institute of Allergy and Infectious Diseases (NIAID)
Last updated: January 14, 2026
Sourced from a government-validated database.Claim as a partner

Initiation of treatment during acute HIV infection seems to result in greater suppression of viral replication than noted during chronic infection and better recovery of certain CD4 subpopulations. However, it is difficult for patients treated during acute infection to maintain long-term continuous antiretroviral (ARV) treatment because of difficulty adhering to complicated medication regimens, drug-related toxicities, and cost of medications. Acutely infected patients who have undergone early initiation of treatment followed by structured treatment interruptions (STIs) appear to have lower off-treatment viral loads than historical controls. This study will evaluate whether effective ARV treatment during acute and early HIV infection followed by STI will result in lower viral setpoints than would otherwise be expected. This trial will have 2 steps and will last for a maximum of 104 weeks. Participants will either enter Step 1 and continue on to Step 2 or enter Step 2 directly. During Step 1, participants with acute or early HIV infection will be given 24 weeks of ARV therapy. Participants may take any combination of FDA-approved ARV medications that they and their doctors select. Participants will have study visits at study entry and Weeks 1, 4, 8, and 20. After 24 weeks on Step 1, participants may enroll in Step 2. Participants in Step 1 and people with early or acute HIV infection who began ARV treatment within 21 days of diagnosis and have had no more than 1 year of treatment may enroll in Step 2. During Step 2, participants will be randomly assigned to one of two study arms: * Arm 1: Participants will continue taking ARV therapy for 16 weeks and then stop ARVs for 64 weeks. * Arm 2: Participants will stop ARVs for 4 weeks, take ARVs for 8 weeks, stop ARVs for 4 weeks, take ARVs for 8 weeks, and then stop ARVs for 56 weeks. Participants in both study arms will restart ARVs regardless of STI duration if their viral load is above 50,000 copies/ml, they progress to CDC category C disease, or their CD4 count falls below 350 cells/mm3 or declines more than 50% from the last on-treatment CD4 level. Step 2 will last 80 weeks. For the first year, participants will have study visits every 1 to 4 weeks, depending on whether they are taking ARVs. During the second year, participants will have study visits every 8 weeks. Study visits will include a brief medical history, blood and pregnancy tests, and voluntary behavioral questionnaires.

Official TitleA Randomized, Multicenter Trial to Determine Whether Induction Therapy Followed by Treatment Interruption is Superior to Induction Therapy Alone in the Treatment of Primary HIV Infection (PHI): The Structured Treatment Interruption (STI) Study 
NCT00084032
Principal SponsorNational Institute of Allergy and Infectious Diseases (NIAID)
Last updated: January 14, 2026
Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.
Treatment Study
These studies test new ways to treat a disease, condition, or health issue. The goal is to see if a new drug, therapy, or approach works better or has fewer side effects than existing options.

How participants are assigned to different groups/arms
In this clinical study, participants are placed into groups randomly, like flipping a coin. This ensures that the study is fair and unbiased, making the results more reliable. By assigning participants by chance, researchers can better compare treatments without external influences.

Other Ways to Assign Participants
Non-randomized allocation
: Participants are assigned based on specific factors, such as their medical condition or a doctor's decision.

None (Single-arm trial)
: If the study has only one group, all participants receive the same treatment, and no allocation is needed.

How treatments are given to participants
Participants are divided into different groups, each receiving a specific treatment at the same time. This helps researchers compare how well different treatments work against each other.

Other Ways to Assign Treatments
Single-group assignment
: Everyone gets the same treatment.

Cross-over assignment
: Participants switch between treatments during the study.

Factorial assignment
: Participants receive different combinations of treatments.

Sequential assignment
: Participants receive treatments one after another in a specific order, possibly based on individual responses.

Other assignment
: Treatment assignment does not follow a standard or predefined design.

How the effectiveness of the treatment is controlled
In a non placebo-controlled study, no participants receive an inert substance (placebo) to compare outcomes. Instead, all participants receive either the experimental treatment or an alternative treatment (often the Standard of Care). This method allows researchers to compare the effects of the experimental treatment with those of a different active intervention, rather than a placebo.

Other Options
Placebo-Controlled
: A placebo is used to compare the effects of the experimental treatment with those of an inert substance, isolating the true treatment effect.

How the interventions assigned to participants is kept confidential
Everyone involved in the study knows which treatment is being given. This is typically used when it's not possible or necessary to hide the treatment details from participants or researchers.

Other Ways to Mask Information
Single-blind
: Participants do not know which treatment they are receiving, but researchers do.

Double-blind
: Neither participants nor researchers know which treatment is given.

Triple-blind
: Participants, researchers, and outcome assessors do not know which treatment is given.

Quadruple-blind
: Participants, researchers, outcome assessors, and care providers all do not know which treatment is given.

Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.
Conditions
Criteria
Any sexBiological sex of participants that are eligible to enroll.
Over 18 YearsRange of ages for which participants are eligible to join.
Healthy volunteers not allowedIf individuals who are healthy and do not have the condition being studied can participate.
Conditions
Pathology
Blood-Borne Infections
Urogenital Diseases
Genital Diseases
Acquired Immunodeficiency Syndrome
Communicable Diseases
Immunologic Deficiency Syndromes
Immune System Diseases
Infections
Pathologic Processes
Retroviridae Infections
RNA Virus Infections
Sexually Transmitted Diseases
Slow Virus Diseases
Virus Diseases
Sexually Transmitted Diseases, Viral
HIV Infections
Lentivirus Infections
Disease Attributes
Criteria

Note: Step 2, Arm 3 has been eliminated as of 12/13/04. Inclusion Criteria for Step 1: * Acute or early HIV infection as defined by the study * Agrees to use acceptable methods of contraception * Agrees to begin antiretroviral treatment regimen within 21 days of diagnosis and no more than 3 days after study entry Exclusion Criteria for Step 1: * Unwilling to follow random assignment in Step 2 * Abnormal laboratory result within 21 days prior to study entry, unless abnormality is considered part of acute HIV infection * Have taken antiretroviral drugs other than for postexposure prophylaxis (PEP). Patients who have undergone up to 30 days of previous PEP treatment are not excluded. * Pregnancy or breastfeeding * Previous participation in an HIV vaccine trial * Previous use of experimental therapeutic immunizations or cytokine infusions Inclusion Criteria for Participants Enrolling Directly into Step 2: * Viral load of less than 400 copies/ml * Enrolled in the AIEDRP CORE01 study, with stored blood samples obtained within 21 days prior to starting treatment on CORE01 * Currently receiving antiretroviral treatment regimen, with no interruptions for more than 7 consecutive days since the beginning of treatment * Antiretroviral treatment was started within 21 days after HIV diagnosis * Agrees to use acceptable methods of contraception Exclusion Criteria for Step 2: * Unwilling to follow random assignment to study arms and follow scheduled treatment interruptions * More than 52 weeks of ARV treatment since diagnosis of acute/early HIV infection prior to entering Step 2 * CD4 count less than 350 cells/mm3 within 28 days of entry into Step 2 * AIDS-defining illness * Pregnant or breastfeeding * Previous participation in an HIV vaccine trial * Previous use of experimental therapeutic immunizations or cytokine infusions


Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.
Treatment Groups
Study Objectives
2 intervention groups 

are designated in this study

This study does not include a placebo group 

Treatment Groups
Group I
Experimental
In Step 1, participants will receive ARV therapy for 24 weeks. Upon entering Step 2, participants will continue taking ARV therapy for 16 weeks and then stop ARVs for 64 weeks.

Treatment interruption schedule is dependent on the Arm in which participants are enrolled in Step 2

Participants will take any combination of FDA-approved ARV medications prescribed by their physician
Group II
Experimental
In Step 1, participants will receive ARV therapy for 24 weeks. Upon entering Step 2, participants will stop ARVs for 4 weeks, take ARVs for 8 weeks, stop ARVs for 4 weeks, take ARVs for 8 weeks, and then stop ARVs for 56 weeks.

Treatment interruption schedule is dependent on the Arm in which participants are enrolled in Step 2

Participants will take any combination of FDA-approved ARV medications prescribed by their physician
Study Objectives
Primary Objectives


Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.
This study has no location dataSave this study to your profile to know when the location data is available. 

SuspendedNo study centers
;