{"id":15482,"date":"2011-08-01T11:35:36","date_gmt":"2011-08-01T11:35:36","guid":{"rendered":"http:\/\/i-base.info\/htb\/?p=15482"},"modified":"2012-08-04T08:22:13","modified_gmt":"2012-08-04T08:22:13","slug":"maraviroc-plus-atazanavirr-without-nukes-versus-standard-of-care-48-week-results","status":"publish","type":"post","link":"https:\/\/i-base.info\/htb\/15482","title":{"rendered":"Maraviroc plus atazanavir\/r without nukes versus standard of care: 48 week results"},"content":{"rendered":"

\"\"Simon Collins, HIV i-Base<\/strong><\/p>\n

Updated results from a Pfizer-sponsored study of dual therapy maraviroc plus atazanavir\/r compared to standard of care atazanavir\/r plus tenofovir\/FTC were presented at the meeting.<\/p>\n

This is controversial due to the lower percentage of patients in the maraviroc arm reaching undetectable viral load <50 copies\/mL at week 48 (75% vs 84%, no between arm statistical data presented due to lack of power in the study size), higher rates of toxicity and the decision to enroll a larger phase 3 study with the same design. These differences were also seen at week 48 when stratified by baseline viral <100,000 (77% vs 87%) and >100,000 (69% vs 77%).<\/p>\n

These trends were apparent in the interim 24-week results presented at the IAS 2010 in Vienna: viral suppression then was 80 vs 89% together with increased side effects (ie 33% vs 23% grade 3\/4 including 26% vs 13% hyperbilirubinaemia) in the maraviroc arm. [2]<\/p>\n

A health economic interest in this study comes from the pharmacokinetic data supporting the use of half-dose (and therefore half-cost) maraviroc (patients are dosed at 150 mg daily when using atazanavir\/r) and that in this combination maraviroc is only taken once daily.<\/p>\n

Mean change from baseline in CD4 count at week 48 was similar with +215 vs +226 cells\/mm3 in the maraviroc vs tenofovir\/FTC arms respectively.<\/p>\n

Grade 3\/4 side effects were more frequent with maraviroc than tenofovir\/FTC (18 vs 11 patients) and these were mostly due to hyperbilirubinemia. Creatinine clearance was stable with maraviroc but decreased by a median \u009612 mL\/min with tenofovir\/FTC. Serious adverse events were similar (10 vs 11 patients) with none related to assigned study drug.<\/p>\n

A second presentation included an analysis of the results from patients who used 150 mg maraviroc with boosted PI, supporting the reduced dose compared to those using 300 mg twice-daily with either tipranavir or fosamprenavir in the maraviroc registrational trials. [3]<\/p>\n

In summary, suppression to <50 copies\/mL was reported in 45% vs 47% in the 150 mg\/boosted PI vs 300 mg groups (vs 16% for the placebo group) with a similar close relationship between doses for people starting in advanced disease with baseline viral load >100,000 copies\/mL (38% vs 39%) or CD4 counts <50 cells\/mm3 (17% vs 18%).<\/p>\n

comment<\/strong><\/p>\n

The limitations from low study numbers in phase 2 studies are important to remember when reviewing these results but it will be important to follow the phase 3 study of this dual therapy arm carefully. Some combinations that are less virologically effective perform better as switch options once people are stable on treatment. <\/strong><\/p>\n

A switch strategy, given the potential cost savings from the reduced dose of maraviroc might warrant a separate study.<\/strong><\/p>\n\n

References<\/p>\n

    \n
  1. 1. Mills A et al. 48-week results of a dual-therapy regimen of once-daily maraviroc (MVC) 150 mg in combination with ritonavir-boosted atazanavir (ATV\/r) compared to emtricitabine\/tenofovir (FTC\/TDF) + ATV\/r in treatment-naive (TN) patients infected with CCR5-tropic HIV-1 (Study A4001078). 6th IAS Conference, 17\u2013\u009620 July 2011, Rome. Abstract TUAB0103<\/a>.\u00a0Webcast<\/a>.<\/li>\n
  2. Portsmouth S et al. Safety and immunovirological activity of once daily maraviroc (MVC) in combination with ritonavir-boosted atazanavir (ATV\/r) compared to emtricitabine 200mg\/tenofovir 300mg QD (TDF\/FTC) + ATV\/r in treatment-na\ued65 patients infected with CCR5-tropic HIV-1 (Study A4001078): A week 24 planned interim analysis. 18th IAS Conference, 18\u2013\u009623 July 2010, Vienna. Late breaker abstract THLBB203<\/a>.<\/li>\n
  3. Taylor S et al. Efficacy of maraviroc (MVC) administered once daily (QD) or twice daily (BID) with boosted protease inhibitors (bPIs) to treatment-experienced patients. 6th IAS Conference, 17\u0096\u201320 July 2011, Rome. Abstract TUAB0106<\/a>.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

    Simon Collins, HIV i-Base Updated results from a Pfizer-sponsored study of dual therapy maraviroc plus atazanavir\/r compared to standard of care atazanavir\/r plus tenofovir\/FTC were presented at the meeting. This is controversial due to the lower percentage of patients in …<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,3],"tags":[94],"class_list":["post-15482","post","type-post","status-publish","format-standard","hentry","category-conference-reports","category-antiretrovirals","tag-ias-6th-2011"],"_links":{"self":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/15482","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/comments?post=15482"}],"version-history":[{"count":0,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/15482\/revisions"}],"wp:attachment":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/media?parent=15482"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/categories?post=15482"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/tags?post=15482"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}