MARCH is an international, multicentre trial planning to enroll 380 HIV-1 infected patients who are currently on 2N(t)RTI + PI/r regimen and virologically suppressed. Participants will be randomized (1:2:2) to one of three treatment groups: to continue their current treatment regimen, maraviroc dose at 150 mg twice daily with PI/r, or maraviroc at 300 mg twice daily with 2N(t)RTI. As the participants population have HIV RNA <200 copies/mL, the phenotypic assessment of tropism cannot be used to determine tropism, instead we will employ the genotypic assessment of tropism by sequencing the V3 loop of the HIV envelope. The main aim of this study is to investigate whether switching to maraviroc, in combination with either RTI or PI/r, is as good at keeping the HIV viral load undetectable as the combination of RTI with PI/r. The other aim is to see if switching to these combinations with maraviroc will improve some of the side effects that can be seen when people take combination therapy including RTI and PI/r.

The study hypothesis is that in stable, virologically suppressed (plasma HIV-RNA <200 copies/mL) patients with no history of prior virological failure, a switch to either MVC dosed at 300mg twice daily (bid) combined with the same 2N(t)RTI backbone regimen or MVC dosed at 150mg twice daily (bid) with the current PI/r (or 300mg bid at the discretion of the investigator if the PI/r is fosamprenavir/r) provides similar (non-inferior) antiretroviral efficacy compared to continuation of the current 2N(t)RTI + PI/r regimen.

Inclusion Criteria:

• Documented HIV-1 infection by a licensed diagnostic test at any time prior to study entry
• Age >18 years
• HIV-1 RNA <200 copies/mL plasma for at least 24 weeks
• Stable (>24 weeks) ART including two N(t)RTIs and a PI/r
• No evidence of any primary HIV genotypic mutations in HIV reverse transcriptase or protease for all patients with available resistance testing results conducted prior to cART and/or during viral rebound/failure
• Provision of written, informed consent.

Exclusion Criteria:

• CXCR4 or CCR5/CXCR4 dual tropic HIV tropism or a non-reportable tropism result based on assessment using proviral DNA

• Anticipated need to modify current cART regimen for toxicity management in the next 6 months

• The following laboratory criteria,

  1. absolute neutrophil count (ANC) <750 cells/µL
  2. haemoglobin <8.0 g/dL
  3. platelet count <50,000 cells/µL
  4. serum AST, ALT >5 x upper limit of normal (ULN)

• Active hepatitis B co-infection

• Pregnant women or nursing mothers

• Current use of any prohibited medications as described in product specific information.

• Hypersensitivity to soy or peanuts

• Acute therapy for serious infection or other serious medical illness (in the judgement of the site Principal Investigator) requiring systemic treatment and/or hospitalisation

• Use of immunomodulators (e.g. systemic corticosteroids, recombinant interleukin-2, interferon) within 30 days prior to screening

• Patients with current alcohol or illicit substance use that in the opinion of the site Principal Investigator would conflict with any aspect of the conduct of the study

• Patients unlikely to be able to remain in follow-up for the protocol-defined period

• Prisoners or subjects who are compulsorily detained (involuntary incarcerated).