Open-label, Follow-up of Doravirine/Islatravir (DOR/ISL 100 mg/0.75mg) for Participants With Human Immunodeficiency Virus-1 (HIV-1) Infection (MK-8591A-033)

NCT04776252 | Active Not Recruiting Phase 3 FDA Drug

• 6 other identifiers: 8591A-033MK-8591A-033jRCT20312105282024-512215-53-00U1111-1304-79262020-001191-14
• Study Type: interventional
• Target: 2,000
• Locations: 16 countries
• Sites: 93

Brief Summary

The safety and tolerability of MK-8591A, a 2-drug fixed dose combination (FDC) of doravirine (100mg) and islatravir (0.75mg) \[DOR/ISL 100 mg/0.75 mg) will be evaluated in participants with Human Immunodeficiency Virus -1 (HIV-1) who were treated with DOR and ISL in earlier clinical studies.

Conditions

HIV-1 Infection

Outcome Measures

Primary Outcomes (2)

• Participants with serious adverse events (SAEs)

  Percentage of participants with serious adverse events (SAEs)

  Up to Week 198

• Participants who discontinued due to an adverse event (AE)

  Percentage of participants who discontinued study treatment due to an AE.

  Up to Week 192

Study Arms (1)

MK-8591A

EXPERIMENTAL

Fixed dose combination (FDC) tablet of 100 mg doravirine, 0.75 mg islatravir taken orally, once daily for up to 192 weeks.

Drug: MK-8591A

Interventions

MK-8591A DRUG

FDC tablet of 100 mg doravirine, 0.75 mg islatravir taken orally, once daily for up to 192 weeks

MK-8591A

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Is currently receiving DOR 100 mg/ISL 0.75 mg adult FDC tablet in an MSD-sponsored clinical study and has completed the last treatment visit.
• Is considered by the investigator to have derived clinical benefit from receiving DOR/ISL and for whom further treatment with DOR/ISL is considered clinically appropriate.
• Female is not pregnant or breastfeeding, and at least one of the following conditions applies: Is not a woman of childbearing potential (WOCBP); or is a non-pregnant WOCBP who agrees to the following during the intervention period and for at least 6 weeks after the last dose of study intervention: Not be sexually active, or if sexually active, to use an acceptable method of contraception; or is pregnant and continues to receive study intervention (where allowed by local regulations and as appropriate based on available data/local standard-of-care guidelines)

You may not qualify if:

• Is taking or is anticipated to require any prohibited therapies.

Sponsors & Collaborators

• Merck Sharp & Dohme LLC: lead

Study Sites (93)

Pueblo Family Physicians ( Site 0010)

Phoenix, Arizona, 85015, United States

Location

One Community Health ( Site 0045)

Sacramento, California, 95811, United States

Location

Whitman-Walker Institute ( Site 0039)

Washington D.C., District of Columbia, 20005, United States

Location

Georgetown University Medical Center-Clinical Trials Unit Division of Infectious Diseases ( Site 002

Washington D.C., District of Columbia, 20007, United States

Location

Midway Immunology and Research Center ( Site 0033)

Ft. Pierce, Florida, 34982, United States

Location

Orlando Immunology Center ( Site 0017)

Orlando, Florida, 32803, United States

Location

Bliss Healthcare Services-Research ( Site 0030)

Orlando, Florida, 32806, United States

Location

Triple O Research Institute, P.A ( Site 0031)

West Palm Beach, Florida, 33407, United States

Location

Chatham County Health Department - Chatham CARE Center-Infectious Disease ( Site 0015)

Savannah, Georgia, 31401, United States

Location

Northstar Healthcare ( Site 0003)

Chicago, Illinois, 60657, United States

Location

KC CARE Health Center-Clinical Trials ( Site 0012)

Kansas City, Missouri, 64111, United States

Location

ID Care ( Site 0028)

Hillsborough, New Jersey, 08844, United States

Location

Icahn School of Medicine at Mount Sinai-Clinical and Translational Research Center ( Site 0006)

New York, New York, 10029, United States

Location

Penn Medicine: University of Pennsylvania Health System-Perelman Center for Advanced Medicine ( Site

Philadelphia, Pennsylvania, 19104, United States

Location

St Hope Foundation ( Site 0041)

Bellaire, Texas, 77401, United States

Location

North Texas Infectious Diseases Consultants, P.A-Research ( Site 0004)

Dallas, Texas, 75246, United States

Location

Texas Center for Infectious Disease Associates-Clinical Research ( Site 0026)

Fort Worth, Texas, 76104, United States

Location

The Crofoot Research Center ( Site 0008)

Houston, Texas, 77098, United States

Location

Holdsworth House Medical Practice ( Site 0700)

Darlinghurst, New South Wales, 2010, Australia

Location

St Vincent's Hospital-IBAC ( Site 0702)

Sydney, New South Wales, 2010, Australia

Location

Fiona Stanley Hospital ( Site 0706)

Murdock, Western Australia, 6150, Australia

Location

Sheldon M. Chumir Health Centre-Southern Alberta Clinic ( Site 0106)

Calgary, Alberta, T2R 0X7, Canada

Location

Vancouver Infectious Diseases Centre ( Site 0100)

Vancouver, British Columbia, V6Z 2C7, Canada

Location

Hamilton Health Sciences- Urgent Care Centre-SIS Clinic ( Site 0109)

Hamilton, Ontario, L8S 1A4, Canada

Location

Maple Leaf Research ( Site 0105)

Toronto, Ontario, M5G 1K2, Canada

Location

Toronto General Hospital ( Site 0104)

Toronto, Ontario, M5G 2C4, Canada

Location

Clinique de médecine Urbaine du Quartier Latin ( Site 0110)

Montreal, Quebec, H2L 4E9, Canada

Location

Clinique Medicale lActuel ( Site 0108)

Montreal, Quebec, H2L 4P9, Canada

Location

Biomedica Research Group-Infectology ( Site 0201)

Santiago, Region M. de Santiago, 7500710, Chile

Location

Centro de Investigacion Clinicadela Universidad Catolica ( Site 0204)

Santiago, Region M. de Santiago, 8330034, Chile

Location

Universidad de Chile - Hospital Clínico Universidad de Chile ( Site 0200)

Santiago, Region M. de Santiago, 8380420, Chile

Location

Hospital hernan henriquez aravena de temuco-Unidad de Investigación Clínica ( Site 0202)

Temuco, Región de la Araucanía, 4781151, Chile

Location

Fundacion Valle del Lili- CIC ( Site 0300)

Cali, Valle del Cauca Department, 760032, Colombia

Location

Centre Hospitalier Universitaire de Nice - Hôpital l'Archet ( Site 1504)

Nice, Alpes-Maritimes, 06202, France

Location

Centre Hospitalier Universitaire Dijon Bourgogne - Hôpital François Mitterrand ( Site 1516)

Dijon, Bourgogne-Franche-Comté, 21000, France

Location

CHU de Bordeaux Hop St ANDRE-Médecine interne et maladies infectieuses ( Site 1512)

Bordeaux, Gironde, 33075, France

Location

CHU de Toulouse-Infectious Disease-Tropical Diseases ( Site 1505)

Toulouse, Haute-Garonne, 31400, France

Location

CHU Charles Nicolle-Inefectious disease ( Site 1506)

Rouen, Haute-Normandie, 76031, France

Location

Hospital La Colombière ( Site 1518)

Montpellier, Herault, 34090, France

Location

Centre Hospitalier Universitaire de Nantes - L' Hopital l'hôtel-Dieu ( Site 1517)

Nantes, Loire-Atlantique, 44093 Cedex 1, France

Location

Tourcoing Hospital-Service Universitaire des Maladies Infectieuses et du Voyageur ( Site 1519)

Tourcoing, Nord, 59200, France

Location

Hôpital de la Croix Rousse-Service des Maladies infectieuses et tropicales ( Site 1503)

Lyon, Rhone, 69004, France

Location

Hôpital Bichat - Claude-Bernard-infectious diseases ( Site 1523)

Paris, 75018, France

Location

Hôpital Avicenne ( Site 1502)

Bobigny, Île-de-France Region, 93000, France

Location

Hôpital Saint-Louis-Infectious Diseases and tropical diseases ( Site 1511)

Paris, Île-de-France Region, 75010, France

Location

Pitie Salpetriere University Hospital-Infectious Disease - Tropical Diseases ( Site 1508)

Paris, Île-de-France Region, 75013, France

Location

Medizinische Hochschule Hannover-Department of Immunology and Rheumatology ( Site 1661)

Hanover, Lower Saxony, 30625, Germany

Location

Fondazione Policlinico Universitario Agostino Gemelli-UOC Malattie Infettive ( Site 1606)

Rome, Lazio, 00168, Italy

Location

Ospedale San Raffaele-U.O. Malattie Infettive ( Site 1602)

Milan, Lombardy, 20127, Italy

Location

Fondazione IRCCS Policlinico San Matteo-Dipartimento di Malattie Infettive: SC Malattie Infettive (

Pavia, Lombardy, 27100, Italy

Location

Ospedale Luigi Sacco-UOC Malattie Infettive I ( Site 1600)

Milan, Milano, 20157, Italy

Location

National Hospital Organization Nagoya Medical Center ( Site 0903)

Nagoya, Aichi-ken, 460-0001, Japan

Location

Tokyo Medical University Hospital ( Site 0904)

Shinjuku-ku, Tokyo, 160-0023, Japan

Location

Center Hospital of the National Center for Global Health and Medicine ( Site 0901)

Shinjyuku-ku, Tokyo, 162-8655, Japan

Location

National Hospital Organization - Osaka National Hospital - Institute For Clinical Research ( Site 09

Osaka, 540-0006, Japan

Location

Tokyo Metropolitan Komagome Hospital ( Site 0906)

Tokyo, 113-8677, Japan

Location

Christchurch Hospital-Infectious Diseases ( Site 0800)

Christchurch, Canterbury, 8011, New Zealand

Location

Wrocl.Centr.Zdrowia SPZOZ Osr. Prof-Lecz Ch. Zak. i Terapii Uzaleznien ( Site 1703)

Wroclaw, Lower Silesian Voivodeship, 50-136, Poland

Location

EMC Instytut Medyczny S. A. Przychodnia przy ul. Lowieckiej we Wroclawiu ( Site 1700)

Wroclaw, Lower Silesian Voivodeship, 50-220, Poland

Location

Wojewódzki Szpital Zakaźny w Warszawie ( Site 1702)

Warsaw, Masovian Voivodeship, 01-201, Poland

Location

WSS im. W Bieganskiego O. Chorob Zakaznych i Hepatologii-F ( Site 1701)

Ód, Łódź Voivodeship, 90-001, Poland

Location

Kuzbasskiy Center for the Prevention and Control of AIDS ( Site 2305)

Kemerovo, Kemerovo Oblast, 650056, Russia

Location

Krasnoyarsk Regional Center for the Prevention and Control of AIDS ( Site 2304)

Krasnoyarsk, Krasnoyarsk Krai, 660049, Russia

Location

Republican Clinical Infectious Hospital ( Site 2300)

Saint Petersburg, Leningradskaya Oblast', 196645, Russia

Location

Moscow Infectious Diseases Clinical Hospital Number 2 ( Site 2306)

Moscow, Moscow, 105275, Russia

Location

Scientific Advisory Clinical Diagnostic Center Central Resea-Federal AIDS Center ( Site 2302)

Moscow, Moscow, 105275, Russia

Location

Saint-Petersburg Center for Prophylactic of AIDS and Infecti-Saint-Petersburg Center for Prophylact

Saint Petersburg, Sankt-Peterburg, 190020, Russia

Location

Smolensk Center for prevention and control of AIDS ( Site 2308)

Smolensk, Smolensk Oblast, 214006, Russia

Location

Republican Clinical Hospital for Infectious Diseases A.F. Agafonova ( Site 2303)

Kazan', Tatarstan, Respublika, 420140, Russia

Location

Josha Research ( Site 2403)

Bloemfontein, Free State, 9300, South Africa

Location

Ezintsha ( Site 2404)

Johannesburg, Gauteng, 2193, South Africa

Location

Mediclinc Muelmed ( Site 2401)

Pretoria, Gauteng, 0083, South Africa

Location

King Edward VIII Hospital ( Site 2410)

Durban, KwaZulu-Natal, 4001, South Africa

Location

Wentworth Hospital ( Site 2400)

Durban, KwaZulu-Natal, 4052, South Africa

Location

Desmond Tutu Health Foundation ( Site 2402)

Cape Town, Western Cape, 7925, South Africa

Location

Hospital General Universitario de Elche-Infectius Disease ( Site 1908)

Elche, Alicante, 03202, Spain

Location

Hospital Germans Trias i Pujol-Fundació Lluita contra la Sida ( Site 1901)

Badalona, Barcelona, 08916, Spain

Location

HOSPITAL CLÍNIC DE BARCELONA-Infection Day Hospital ( Site 1900)

Barcelona, Catalonia, 08036, Spain

Location

HOSPITAL GENERAL UNIVERSITARIO GREGORIO MARAÑON-Unidad de Enfermedades Infecciosas ( Site 1903)

Madrid, Madrid, Comunidad de, 28007, Spain

Location

Hospital Universitario Infanta Leonor ( Site 1906)

Madrid, 28031, Spain

Location

Hospital Universitario Fundación Jiménez Díaz-Internal Medicine. Infectious disease ( Site 1902)

Madrid, 28040, Spain

Location

Hospital Universitario La Paz-Internal Medicine ( Site 1904)

Madrid, 28046, Spain

Location

University Hospital Basel-Infectiology ( Site 2002)

Basel, Canton of Aargau, 4031, Switzerland

Location

Hôpitaux Universitaires de Genève (HUG)-Infectious Disease Department ( Site 2004)

Geneva, Canton of Geneva, 1211, Switzerland

Location

Cantonal Hospital St.Gallen ( Site 2001)

Sankt Gallen, Canton of St. Gallen, 9007, Switzerland

Location

UniversitätsSpital Zürich ( Site 2000)

Zurich, Canton of Zurich, 8091, Switzerland

Location

Ospedale Regionale di Lugano, Sede Civico-Servizio Malattie Infettive ( Site 2005)

Lugano, Canton Ticino, 6903, Switzerland

Location

Inselspital Bern-Inselspital Infektiologie ( Site 2003)

Bern, 3010, Switzerland

Location

Brighton and Sussex University Hospitals NHS Trust ( Site 2104)

East Sussex, Brighton And Hove, BN2 5BE, United Kingdom

Location

Southmead Hospital ( Site 2103)

Bristol, Bristol, City of, BS10 5NB, United Kingdom

Location

Royal Free Hospital ( Site 2102)

London, England, NW32QG, United Kingdom

Location

King's College Hospital ( Site 2101)

London, England, SE5 9RS, United Kingdom

Location

North Manchester General Hospital ( Site 2105)

Manchester, M8 5RB, United Kingdom

Location

Related Links

• Merck Clinical Trials Information
• Plain Language Summary

Study Officials

• Medical Director

  Merck Sharp & Dohme LLC

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 26, 2021
• First Posted: March 1, 2021
• Study Start: September 15, 2021
• Primary Completion (Estimated): May 29, 2029
• Study Completion (Estimated): May 29, 2029
• Last Updated: December 23, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share

Locations

GB (5); CL (4); FR (13); RU (8); PL (4); CO (1); IT (4); ES (7); JP (5); ZA (6); CH (6); US (18); AU (3); NZ (1); CA (7); DE (1)