VorinostatOther Names: MK-0683, VOR, Zolinza, suberoylanilide hydroxamic acid (SAHA) Drug Class: Latency-Reversing Agents Molecular Formula: C14 H20 N2 O3 Registry Number: 149647-78-9 (CAS) Chemical Name: 8-(hydroxyamino)-8-oxo-N-phenyl-octanamide Chemical Class: Other Carboxylic Acid Derivatives Organization: Merck & Co., Inc. Phase of Development: Vorinostat is in Phase 2 development as a latency-reversing agent for HIV.
(Compound details obtained from ChemIDplus Advanced,1 NIAID Therapeutics Database,2 and Treatment Action Group website3)
What is vorinostat?
Vorinostat (brand name: Zolinza) is a drug that has been approved by the(FDA) for the treatment of cancer. It is also being studied as part of a possible strategy to cure HIV .4-8
As an HIV drug, vorinostat belongs to a general group of drugs called.3
How do latency-reversing agents work?
Currently, there is no cure for HIV infection. One of the main obstacles to curing HIV infection is that thecan remain hidden and inactive (latent) inside certain cells of the (such as resting CD4 cells) for many months or even years. The cells where latent HIV hides are known as the . Because HIV in this latent state is inactive, the immune system cannot detect the virus, and the (ARV) drugs that are used to treat HIV have no effect on it.9,10
Latency-reversing agents work by drawing HIV out of its latent state within resting CD4 cells. Once the latent HIV is reactivated, the CD4 cells that harbor the virus are more likely to be recognized and killed by the body’s immune system or may be killed by certain HIV therapies, such as those that can enhance the body's What is a Latent HIV Reservoir? fact sheet.to HIV. Researchers hope that the combined use of vorinostat and other HIV-fighting strategies, including ongoing (ART), may fully eliminate HIV from the body.10–12 To learn more, see the AIDSinfo
Which clinical trials are studying vorinostat?
Study Name: NCT01319383
Status: This study has been completed.
Location: United States
Purpose: The purpose of this study was to determine the effectiveness of a single of vorinostat in activating latent HIV in resting CD4 cells versus when given as multiple doses in a follow-on study.7
Study Names: SEARCH 019; NCT02475915 and SEARCH 026; NCT02470351
Status: These studies have been completed.
Purpose: The SEARCH 019 study evaluated the safety and effectiveness of a that combined vorinostat, the drugs hydroxychloroquine and maraviroc, and ART in controlling levels during a treatment interruption. The researchers compared this combination to ART alone.13,14
SEARCH 026 was an observational sub-study that was conducted at the same time as SEARCH 019 and included some of the SEARCH 019 participants. The sub-study evaluated how the treatment regimens used in SEARCH 026 affected the(CNS), latent HIV in the CNS, and viral load levels in the CNS of the participants in the sub-study before, during, and after they received the treatments.13,15
Study Name: NCT01365065
Status: This study has been completed.
Purpose: The purpose of this study was to determine whether vorinostat could activate latent HIV in resting CD4 cells of adults whose HIV was well controlled by ART.3,6
Study Names: RIVER trial; NCT02336074
Status: This study is ongoing, but not recruiting participants.
Location: United Kingdom
Purpose: The purpose of this study in participants with newly diagnosed HIV is to determine whether a combination of drugs can effectively reduce latent HIV in resting CD4 cells. The combination will include (1) a four-drug ART regimen (which will include the HIV medicine raltegravir) (2) two anti-HIV vaccines, and (3) 10 doses of vorinostat. Researchers will compare this to a four-drug ART regimen given alone.4
For more details on the studies listed above, see the Health Professional version of this drug summary.
Other HIV-related trials involving vorinostat include:
- XTRA trial (NCT03212989): A Phase 1 study will evaluate the effect of vorinostat used with specific types of immune cells (called expanded specific T-cell therapy) on reactivated latent HIV in adults whose HIV is well controlled by ART. This study is currently recruiting participants.16
- ACTG A5366 (NCT03382834): An early Phase 1 study that is studying whether tamoxifen (a drug that acts on the estrogen) can boost vorinostat’s ability to reactivate latent HIV in post-menopausal women whose HIV is well controlled by ART. This study is ongoing, but not recruiting participants.17
- VOR-07 study (NCT03803605): A Phase 1 study that will evaluate the effects of vorinostat and the investigational broadly neutralizing VRC07-523LS on HIV infection in individuals with HIV on ART. This study is currently recruiting participants.18
What side effects might vorinostat cause?
One goal of HIV research is to identify new drugs that have fewer side effects. The following side effects were observed in some of the studies of vorinostat listed above.
In both the initial study and the follow-on study conducted under this study , side effects reported by participants who received vorinostat included mild, temporary symptoms, headache, and low counts.19,20
SEARCH 019 (NCT02475915) and SEARCH 026 (NCT02470351):
In this Phase 1/2 study, two participants in the group taking vorinostat had serious side effects. One participant stopped the study because of poor kidney function and low platelet levels. The other participant had diarrhea that may have been caused by the study drugs or by food poisoning. When compared to participants in the ART-only group, more participants in the group taking vorinostat had low platelet levels and high creatinine levels. (High creatinine levels can mean that the aren’t working well.)13,21
In the sub-study, treatment with vorinostat did not result in the presence of HIV RNA inor other lasting side effects.15,22
In this Phase 2 study, most of the side effects that occurred were not serious. The most common side effects were nausea, diarrhea, fatigue, and low platelet counts.23
RIVER trial (NCT02336074):
In this Phase 2 study, 97% of the participants who received ART plus two therapeutic HIV vaccines plus vorinostat had a side effect. Seventy percent of these side effects were mild and 23% were moderate in intensity. In comparison, 73% of participants receiving ART only had a side effect; 33% were mild and 20% were moderate. No treatment-related serious side effects were reported.4,24,25
Because vorinostat is still being studied as an HIV drug, information on possible side effects of the drug is not complete. As testing of vorinostat continues, additional information on possible side effects will be gathered.
Additional information on side effects known to be associated with vorinostat can be found in the FDA-approved Zolinza Full Prescribing Information.5
Where can I get more information about clinical trials studying vorinostat?
More information about vorinostat-related research studies is available from the AIDSinfo database of study summaries. Click on the title of any trial in the list to see the ClinicalTrials.gov trial summary and more information about the study.
Some clinical trials may be looking for volunteer participants. Your health care provider can help you decide whether participating in a NIH Clinical Research Trials and You.is right for you. For more information, visit
- United States National Library of Medicine. ChemIDplus Advanced: Vorinostat. https://chem.nlm.nih.gov/chemidplus/rn/149647-78-9. Accessed June 25, 2019
- National Institute of Allergy and Infectious Diseases (NIAID). NIAID ChemDB, HIV Drugs in Development. https://chemdb.niaid.nih.gov/DrugDevelopmentHIV.aspx. Accessed June 25, 2019
- Treatment Action Group website. Research toward a cure trials. http://www.treatmentactiongroup.org/cure/trials. Accessed June 25, 2019
- Imperial College London. Research in viral eradication of HIV reservoirs. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on October 23, 2014. NLM Identifier: NCT02336074. https://www.clinicaltrials.gov/ct2/show/NCT02336074. Accessed June 25, 2019
- Merck Sharp & Dohme Corp. Zolinza: full prescribing information, December 2018. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cd86ee78-2781-468b-930c-3c4677bcc092. Accessed June 25, 2019
- Bayside Health. A pilot study to assess the safety and effect on HIV transcription of vorinostat in patients receiving suppressive combination anti-retroviral therapy. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on June 1, 2011. NLM Identifier: NCT01365065. https://www.clinicaltrials.gov/ct2/show/NCT01365065. Accessed June 25, 2019
- University of North Carolina, Chapel Hill. A Phase I/II investigation of the effect of vorinostat (VOR) on HIV RNA expression in the resting CD4+ T cells of HIV-infected patients receiving stable antiretroviral therapy. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on March 17, 2011. NLM Identifier: NCT01319383. https://www.clinicaltrials.gov/ct2/show/NCT01319383. Accessed June 25, 2019
- Argos Therapeutics. Press Release, dated April 1, 2015. NIH funds study of fully personalized immunotherapy AGS-004 combined with a latency reversing therapy for the treatment of HIV. http://ir.argostherapeutics.com/releasedetail.cfm?ReleaseID=904466. Accessed June 25, 2019
- National Institute of Allergy and Infectious Diseases (NIAID). Bulletin: NIAID invites applications to conduct basic research on HIV persistence: studies key to search for a cure. https://wayback.archive-it.org/6721/20160908184013/http://www.niaid.nih.gov/news/newsreleases/Archive/2009/Pages/HIV_persistence.aspx. Published June 16, 2009. Accessed June 25, 2019
- Shattock RJ, Rosenberg Z. Microbicides: topical prevention against HIV. Cold Spring Harb Perspect Med. 2012;2(2):a007385.
- Rasmussen TA, Tolstrup M, Winckelmann A, Østergaard L, Søgaard OS. Eliminating the latent HIV reservoir by reactivation strategies. Hum Vaccines Immunother. 2013;9(4):790–799.
- National Institute of Allergy and Infectious Diseases (NIAID). HIV viral eradication. https://www.niaid.nih.gov/diseases-conditions/hiv-viral-eradication. Accessed June 25, 2019
- South East Asia Research Collaboration with Hawaii. A randomized study to compare the efficacy of vorinostat/hydroxychloroquine/maraviroc (VHM) in controlling HIV after treatment interruption in subjects who initiated ART during acute HIV infection. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on June 3, 2015. NLM Identifier: NCT02475915. https://clinicaltrials.gov/ct2/show/NCT02475915. Accessed June 25, 2019
- Kroon E, Ananworanich J, Eubanks K, et al. Effect of vorinostat, hydroxychloroquine and maraviroc combination therapy on viremia following treatment interruption in individuals initiating ART during acute HIV infection. Abstract presented at: 21st International AIDS Conference (AIDS 2016); July 18-22, 2016; Durban, South Africa. Abstract TUAX0101LB. http://programme.aids2016.org/Abstract/Abstract/10535. Accessed June 25, 2019
- South East Asia Research Collaboration with Hawaii. Study SEARCH 026Assessment of the HIV CNS reservoir, neurological and neuro-cognitive effects, and source of rebound HIV in CNS in subjects participating in Study SEARCH 019. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on June 2, 2015. NLM Identifier: NCT02470351. https://clinicaltrials.gov/ct2/show/NCT02470351. Accessed June 25, 2019
- University of North Carolina, Chapel Hill. IGHID 11627 - A Phase I study to evaluate the effects of vorinostat and HIV-1 antigen expanded specific T cell therapy (HXTC) on persistent HIV-1 infection in HIV-infected individuals started on antiretroviral therapy (The XTRA Study). In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on July 11, 2018. NLM Identifier: NCT03212989. https://clinicaltrials.gov/ct2/show/study/NCT03212989. Accessed June 25, 2019
- National Institute of Allergy and Infectious Diseases (NIAID). Selective estrogen receptor modulators to enhance the efficacy of viral reactivation with histone deacetylase inhibitors. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on December 19, 2017. NLM Identifier: NCT03382834. https://clinicaltrials.gov/ct2/show/record/NCT03382834. Accessed June 25, 2019
- University of North Carolina, Chapel Hill. IGHID 11802 - Combination Therapy With the Novel Clearance Modality (VRC07-523LS) and the Latency Reversal Agent (Vorinostat) to Reduce the Frequency of Latent, Resting CD4+ T Cell Infection (The VOR-07 Study). In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on: January 10, 2019. NLM Identifier: NCT03803605. https://clinicaltrials.gov/ct2/show/NCT03803605. Accessed June 25, 2019
- Archin NM, Bateson R, Tripathy M, et al. HIV-1 expression within resting CD4+ T cells after multiple doses of vorinostat. J Infect Dis. 2014;210(5):728-735. doi:10.1093/infdis/jiu155
- Archin NM, Kirchherr JL, Sung JAM, et al. Interval dosing with the HDAC inhibitor vorinostat effectively reverses HIV latency. J Clin Invest. 127(8):3126-3135. doi:10.1172/JCI92684
- Kroon E, Ananworanich J, Eubanks K, et al. Effect of vorinostat, hydroxychloroquine and maraviroc combination therapy on viremia following treatment interruption in individuals treated during acute HIV infection. 21st International AIDS Conference (AIDS 2016); July 18-22, 2016; Durban, South Africa. Mascolini: Vorinostat, HCQ, Maraviroc Do Not Delay Time to Rebound After Interruption. Conference reports for National AIDS Treatment Advocacy Project (NATAP); 2016. http://www.natap.org/2016/IAC/IAC_07.htm. Accessed June 25, 2019
- Kroon E, Ananworanich J, Le LT, et al. Central nervous system impact of vorinostat, hydroxychloroquine and maraviroc combination therapy followed by treatment interruption in individuals treated during acute HIV infection (SEARCH 026). Poster presented at: International AIDS Conference (AIDS 2016); July 18-22, 2016; Durban, South Africa. Poster LBPE005. http://programme.aids2016.org/PAGMaterial/eposters/0_10588.pdf. Accessed June 25, 2019
- Mota TM, Rasmussen TA, Rhodes A, et al. No adverse safety or virological changes 2 years following vorinostat in HIV-infected individuals on antiretroviral therapy. AIDS. 2017;31(8):1137-1141. doi:10.1097/QAD.0000000000001442
- Fidler S. RIVER research in viral eradication of HIV reservoirs: a two-arm (proof of concept) randomised Phase II trial vorinostat plus a prime boost vaccine. Slides presented at: International AIDS Conference (AIDS 2018): July 23-27, 2018; Amsterdam, the Netherlands. https://programme.aids2018.org/PAGMaterial/PPT/6106_3214/RIVER%20presentation%20at%20IAS%2024.7.2018%20final%20draft.pptx. Accessed June 25, 2019
- Fidler S, Stohr W, Pace M, et al. A randomised controlled trial comparing the impact of antiretroviral therapy (ART) with a “Kick-and-Kill” approach to ART alone on HIV reservoirs in individuals with primary HIV infection (PHI); RIVER trial. Abstract presented at: International AIDS Conference (AIDS 2018); July 23-27, 2018; Amsterdam, the Netherlands. Abstract TUAA0202LB. http://programme.aids2018.org/Abstract/Abstract/12977. Accessed June 25, 2019
Last Reviewed: June 25, 2019