{"id":41866,"date":"2021-12-20T07:38:04","date_gmt":"2021-12-20T07:38:04","guid":{"rendered":"https:\/\/i-base.info\/htb\/?p=41866"},"modified":"2025-07-08T03:53:50","modified_gmt":"2025-07-08T03:53:50","slug":"fda-stop-use-of-islatravir-in-ongoing-studies","status":"publish","type":"post","link":"https:\/\/i-base.info\/htb\/41866","title":{"rendered":"FDA further limits use of islatravir in ongoing studies"},"content":{"rendered":"<p><strong>Simon Collins<\/strong><\/p>\n<p><strong>On 13 December 2021, Merck\/MSD announced a further development concerning islatravir as an investigational compound for HIV treatment and prevention. [1]<\/strong><\/p>\n<p>This includes that the US FDA has now put clinical holds on\u00a0the investigational new drug applications (INDs) for several compounds and indications,<\/p>\n<ul>\n<li>The oral and implant formulations of islatravir (MK-8591) for HIV-1 PrEP.<\/li>\n<li>The injectable formulation of islatravir for HIV-1 treatment and prophylaxis.<\/li>\n<li>The oral doravirine\/islatravir (DOR\/ISL) HIV-1 once-daily treatment.<\/li>\n<\/ul>\n<p>This is based on the concerns for mean reductions in total lymphocyte and CD4 counts reported in three earlier press statements. [2, 3]<\/p>\n<p>This includes now stopping further dosing of the weekly oral formulation being studied with Gilead&#8217;s lenacapavir. [1, 4]<\/p>\n<p>The following studies have been placed on full clinical hold. This includes stopping use of islatravir:<\/p>\n<ul class=\"bwlistdisc\">\n<li>MK-8591-016 \u2013 A phase 2a PrEP study evaluating the safety and pharmacokinetics of oral islatravir once-monthly in participants at low risk of HIV-1 infection.<\/li>\n<li>MK-8591-022 (IMPOWER 22) \u2013 A phase 3 PrEP study evaluating oral islatravir once-monthly in cisgender women at high risk for HIV-1 infection.<\/li>\n<li>MK-8591-024 (IMPOWER 24) \u2013 A phase 3 PrEP study evaluating oral islatravir once-monthly in cisgender men and transgender women who have sex with men, and are at high risk for HIV-1 infection.<\/li>\n<li>MK-8591-034 \u2013 A phase 1 study evaluating injectable islatravir (dosing complete).<\/li>\n<li>MK-8591-035 \u2013 A phase 2 PrEP study evaluating once-monthly oral islatravir in trans and gender diverse individuals (study had not yet opened).<\/li>\n<li>MK-8591-043 \u2013 A phase 2a PrEP study evaluating islatravir implant once-yearly in individuals at low risk for HIV-1 infection (study had not yet opened).<\/li>\n<\/ul>\n<p>The following studies have been placed on partial clinical hold. This stops further enrolment but allows continued used of islatravir.<\/p>\n<ul class=\"bwlistdisc\">\n<li>MK-8591-011 \u2013 A phase 2 dose ranging study of oral DOR\/ISL once-daily and lamivudine (3TC) in treatment-na\u00efve adult participants with HIV-1 infection (fully enrolled).<\/li>\n<li>MK-8591A-017 (ILLUMINATE SWITCH A) \u2013 A phase 3 oral once-daily, open label study evaluating a switch from antiretroviral therapy (ART) to DOR\/ISL in adults with HIV-1 who are virologically suppressed (fully enrolled).<\/li>\n<li>MK-8591A-018 (ILLUMINATE SWITCH B) \u2013 A phase 3 oral once-daily study evaluating a switch from bictegravir\/emtricitabine\/tenofovir alafenamide (BIC\/FTC\/TAF) to DOR\/ISL in adults with HIV-1 who are virologically suppressed (fully enrolled).<\/li>\n<li>MK-8591A-019 (ILLUMINATE HTE) \u2013 A phase 3 study evaluating oral islatravir and DOR\/ISL once-daily in heavily treatment-experienced (HTE) participants with HIV-1 infection.<\/li>\n<li>MK-8591A-020 (ILLUMINATE NAIVE) \u2013 A phase 3 study evaluating oral islatravir and DOR\/ISL once-daily in treatment-na\u00efve participants with HIV-1 infection.<\/li>\n<li>MK-8591A-028 (ILLUMINATE YOUTH) \u2013 A phase 2 open label study evaluating oral DOR\/ISL once-daily for the treatment of HIV-1 infection in paediatric participants who are virologically suppressed on ART for \u22653 months or are treatment-naive.<\/li>\n<li>MK-8591A-033 \u2013 A phase 3 open label follow up of adult and paediatric participants with HIV-1 who were treated with oral DOR\/ISL once-daily in earlier clinical studies.<\/li>\n<\/ul>\n<p>References<\/p>\n<ol>\n<li>Merck\/MSD press release. Merck announces clinical holds on studies evaluation islatravir for the treatment and preventions of HIV-1 infection. (13 December 2021).<br \/>\n<a href=\"https:\/\/www.merck.com\/news\/merck-announces-clinical-holds-on-studies-evaluating-islatravir-for-the-treatment-and-prevention-of-hiv-1-infection\/\">https:\/\/www.merck.com\/news\/merck-announces-clinical-holds-on-studies-evaluating-islatravir-for-the-treatment-and-prevention-of-hiv-1-infection<\/a><\/li>\n<li>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><span lang=\"EN-US\">MSD\/Merck stop once-weekly NNRTI MK-8507: islatravir studies continue with closer monitoring. HTB (November 2021).<\/span><br \/>\n<a href=\"https:\/\/i-base.info\/htb\/41647\"><span lang=\"EN-US\">https:\/\/i-base.info\/htb\/41647<\/span><\/a><\/li>\n<li>Gilead press statement. Gilead and Merck announce temporary pause in enrollment for phase 2 study evaluating an oral weekly combination regimen of investigational islatravir and investigational lenacapavir. (26 November 2021).<br \/>\n<a href=\"https:\/\/www.gilead.com\/news-and-press\/company-statements\/gilead-and-merck-announce-temporary-pause-in-enrollment-for-phase-2-study-evaluating-an-oral-weekly-combination-regimen-of-investigational-islatravir-and-investigational-lenacapavir\">https:\/\/www.gilead.com\/news-and-press\/company-statements\/gilead-and-merck-announce-temporary-pause-in-enrollment-for-phase-2-study-evaluating-an-oral-weekly-combination-regimen-of-investigational-islatravir-and-investigational-lenacapavir<\/a><\/li>\n<\/ol>\n<p><em>This report was first published on 16 December 2021.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Simon Collins On 13 December 2021, Merck\/MSD announced a further development concerning islatravir as an investigational compound for HIV treatment and prevention. [1] This includes that the US FDA has now put clinical holds on\u00a0the investigational new drug applications (INDs) &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-41866","post","type-post","status-publish","format-standard","hentry","category-antiretrovirals"],"_links":{"self":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/41866","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=41866"}],"version-history":[{"count":4,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/41866\/revisions"}],"predecessor-version":[{"id":51621,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/41866\/revisions\/51621"}],"wp:attachment":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/media?parent=41866"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/categories?post=41866"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/tags?post=41866"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}