{"id":44151,"date":"2022-10-03T07:32:03","date_gmt":"2022-10-03T07:32:03","guid":{"rendered":"https:\/\/i-base.info\/htb\/?p=44151"},"modified":"2022-11-12T19:47:45","modified_gmt":"2022-11-12T19:47:45","slug":"islatravir-update-treatment-studies-to-resume-using-a-lower-dose-but-prep-studies-are-discontinued-in-favour-of-mk-8537","status":"publish","type":"post","link":"https:\/\/i-base.info\/htb\/44151","title":{"rendered":"Islatravir update: treatment studies to use a lower dose but PrEP research discontinued in favour of MK-8537"},"content":{"rendered":"<div><strong><span lang=\"EN-US\">Simon Collins, HIV i-Base<\/span><\/strong><\/div>\n<div>\n<p class=\"HTBBODYtext\"><strong><span lang=\"EN-US\">On 29 September 2022, MSD\/Merck announced that studies using the investigational NRTTI islatravir as HIV treatment will continue, but using a new lower dose. [1]<\/span><\/strong><\/p>\n<\/div>\n<div>\n<p class=\"HTBBODYtext\"><span lang=\"EN-US\">This will hopefully overcome the reduction in total lymphocyte and CD4 counts that led to most islatravir studies being stopped at the end of 2021. [2, 3, 4]<\/span><\/p>\n<\/div>\n<div>\n<p class=\"HTBBODYtext\"><span lang=\"EN-US\">The earlier unexpected effect is now being explained by an accumulation of intracellular concentrations of islatravir triphosphate that will hopefully be avoided by using a reduced dose.<\/span><\/p>\n<\/div>\n<div>\n<p class=\"HTBBODYtext\"><span lang=\"EN-US\">New studies will include:<\/span><\/p>\n<\/div>\n<div>\n<ul>\n<li class=\"HTBBODYindent\"><span lang=\"EN-US\">Phase 3 studies using once-daily oral islatravir plus doravirine as initial ART and as a switch therapy.<\/span><\/li>\n<li class=\"HTBBODYindent\">Phase 2 research into once-weekly oral islatravir in combination with once-weekly oral lenacapavir (being developed by Gilead).<\/li>\n<\/ul>\n<\/div>\n<div>\n<p class=\"HTBBODYtext\"><span lang=\"EN-US\">However, dose reductions are not appropriate for the longer-acting formulations of islatravir, including a monthly oral tablet and an annual implant that were both being studied as PrEP.<\/span><\/p>\n<p class=\"HTBBODYtext\"><span lang=\"EN-US\">Instead, the company is planning to continue long-acting PrEP studies using MK-8527, a second NRTTI at an earlier stage of development, in the hope that it might have a different side effect profile and that this might not be a class effect.<\/span><\/p>\n<\/div>\n<div>\n<p class=\"HTBBODYtext\">References<\/p>\n<\/div>\n<div>\n<ol>\n<li class=\"HTBreferences\"><span lang=\"EN-US\">Merck press release. Merck to initiate new phase 3 clinical program with lower dose of daily oral islatravir in combination with doravirine for treatment of people with HIV-1 infection. (29 September 2022).<br \/>\n<\/span><a href=\"https:\/\/www.merck.com\/news\/merck-to-initiate-new-phase-3-clinical-program-with-lower-dose-of-daily-oral-islatravir-in-combination-with-doravirine-for-treatment-of-people-with-hiv-1-infection\">https:\/\/www.merck.com\/news\/merck-to-initiate-new-phase-3-clinical-program-with-lower-dose-of-daily-oral-islatravir-in-combination-with-doravirine-for-treatment-of-people-with-hiv-1-infection<\/a><\/li>\n<li class=\"HTBreferences\">Selected islatravir studies stop enrolment: further complications with important investigational drugs. HTB (6 December 2021).<br \/>\n<a href=\"https:\/\/i-base.info\/htb\/41833\">https:\/\/i-base.info\/htb\/41833<\/a><\/li>\n<li class=\"HTBreferences\">MSD\/Merck stop once-weekly NNRTI MK-8507: islatravir studies continue with closer monitoring. HTB (November 2021).<br \/>\n<a href=\"https:\/\/i-base.info\/htb\/41647\">https:\/\/i-base.info\/htb\/41647<\/a><\/li>\n<li class=\"HTBreferences\">FDA further limit use of islatravir in ongoing studies. HTB (20 December 2021).<br \/>\n<a href=\"https:\/\/i-base.info\/htb\/41866\">https:\/\/i-base.info\/htb\/41866<\/a><\/li>\n<\/ol>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Simon Collins, HIV i-Base On 29 September 2022, MSD\/Merck announced that studies using the investigational NRTTI islatravir as HIV treatment will continue, but using a new lower dose. [1] This will hopefully overcome the reduction in total lymphocyte and CD4 &hellip;<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-44151","post","type-post","status-publish","format-standard","hentry","category-antiretrovirals"],"_links":{"self":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/44151","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\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/comments?post=44151"}],"version-history":[{"count":6,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/44151\/revisions"}],"predecessor-version":[{"id":44360,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/44151\/revisions\/44360"}],"wp:attachment":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/media?parent=44151"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/categories?post=44151"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/tags?post=44151"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}