TheraRadar
Data updated: May 26, 2026

ACYCLOVIR

DNA Polymerase Inhibitors
Infectious Disease Approved 1997-04-22

Acyclovir treats several common viral infections, including shingles and chickenpox. It also helps patients with genital herpes by managing both initial outbreaks and subsequent recurrent episodes. This medication is used to limit the activity of the herpes simplex and varicella-zoster viruses in the body.

Source: FDA Label • NOVITIUM PHARMA • Herpes Simplex Virus Nucleoside Analog DNA Polymerase Inhibitor

How ACYCLOVIR Works

This medication works by utilizing a viral enzyme called thymidine kinase to convert itself into an active form that halts the replication of viral DNA. Once activated, it blocks the viral DNA polymerase and inserts itself into the viral DNA chain to terminate its growth. This selective process prevents the virus from multiplying while leaving healthy cells largely unaffected.

57
Indications
--
Phase 3 Trials
29
Years on Market

ACYCLOVIR Approval History

1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
Original
New Indication
New Form
Label Update
303 FDA actions from 1997 to 2026
Jan 2026 SUPPL
Label · Labeling
May 2025 ORIGINAL
Update
Jun 2024 ORIGINAL
Update

What ACYCLOVIR Treats

3 indications

ACYCLOVIR is approved for 3 conditions since its original approval in 1997. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Herpes Zoster
  • Genital Herpes
  • Chickenpox
Source: FDA Label

ACYCLOVIR Competitive Set

Pro

Three rings of competition based on shared molecular targets and treated indications.

MoA expansion candidates

2

Same target(s), different indications — where else is this mechanism being explored?

Indication competitors

3

Same indication, different mechanism — what else might this patient receive?

Unlock 1 more competitors across all three rings.
Upgrade to Pro

Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

Drugs Similar to ACYCLOVIR

FDA-approved drugs for similar conditions. Compare mechanisms and indications to understand treatment alternatives.

VALTREX
VALACYCLOVIR HYDROCHLORIDE
3 shared
GSK
Shared indications:
Genital HerpesHerpes ZosterChickenpox
FAMCICLOVIR
FAMCICLOVIR
2 shared
MACLEODS PHARMS LTD
Shared indications:
Genital HerpesHerpes Zoster
VALACYCLOVIR HYDROCHLORIDE
VALACYCLOVIR HYDROCHLORIDE
2 shared
RISING
Shared indications:
Genital herpesChickenpox
📋

Clinical Trial Registry

18 trials
Trial Sponsor ID Phase Status Title
NCT03178149 7317-CL-0003 Ph 1 recruiting A Study of the Safety and Tolerability of ASP7317 in Senior Adults Who Are Losing Their Clear, Sharp Central Vision Due to Geographic Atrophy Secondary to Dry Age-related Macular Degeneration
NCT05589688 ACICLOPTIM RC31/21/0610 Ph 1 recruiting Individualization of Dosage Regimens in Obese Patients: Application to Acyclovir
NCT03368664 LemKids results posted EFC13429 U1111-1180-6352, 2016-003100-30 Ph 3 terminated A Study to Evaluate Efficacy, Safety, and Tolerability of Alemtuzumab in Pediatric Patients With RRMS With Disease Activity on Prior DMT
NCT06134492 HerpMV ZKSJ0153 BMBF 01KG2301 Ph 3 recruiting Acyclovir in Ventilated Patients With Pneumonia and HSV-1 in BAL
NCT02073097 results posted CASE3413 Ph 1, Ph 2 completed Carfilzomib, Rituximab, and Combination Chemotherapy in Treating Patients With Diffuse Large B-Cell Lymphoma
NCT00495716 results posted 32545 K23AI071257-01A1 Ph 4 terminated Effect of HSV-2 Suppressive Therapy on Sexual Behavior
NCT02977533 TDU14981 2016-002415-18, U1111-1184-8607 Ph 1 completed A Single Ascending Dose Study of GZ402668 in Patients With Progressive Multiple Sclerosis
NCT03831165 1215208 Ph 4 completed Melatonin Effects on Genital Herpes in Brazilian Women
NCT02151240 Focus-101 cttq-focus-101 Ph 4 completed Efficacy and Safety of Foscarnet Sodium and Sodium Chloride Injection in Patients With Herpes Zoster
NCT02583594 SCALA TDU14260 2015-002550-12, U1111-1171-7939 Ph 1 completed A Study to Characterize Subcutaneous or Intravenous Alemtuzumab in Patients With Progressive Multiple Sclerosis
NCT01833143 results posted 12-222 Ph 2 completed Bortezomib in KRAS-Mutant Non-Small Cell Lung Cancer in Never Smokers or Those With KRAS G12D
NCT00942084 results posted Pro00028772 Ph 1 completed A Study to Describe the Pharmacokinetics of Acyclovir in Premature Infants (PTN_Acyclo)
NCT02047253 results posted F130725012 (UAB 1336) Ph 2 completed Phase 2 Trial of Carfilzomib for Metastatic Castration-resistant Prostate Cancer Following Treatment
NCT00723229 results posted 34187-B U19AI031448 Ph 4 completed A Randomized Trial to Evaluated the Suppressive Effect of Acyclovir on Rapidly Cleared HSV-2 Reactivation
NCT02349828 NEU-SIUSM-15-001 Ph 2, Ph 3 withdrawn Antiviral Prophylaxis in a Burn Population
NCT02282826 TDU13475 2014-001591-61, U1111-1155-6252 Ph 1 completed A First-in-human, Single Ascending Dose Study of GZ402668 in Patients With Progressive Multiple Sclerosis
NCT02255734 YSP-REH3002-01 Ph 4 completed Bioequivalence of Two Formulations of Acyclovir
NCT01026454 ACV-VAL results posted 37162-A Ph 4 completed Valacyclovir vs. Acyclovir as HSV-2 Suppressive Therapy: Effect on Plasma HIV-1 Levels Among HIV-1/HSV-2 Co-infected Persons
🔬

Active Pipeline

Pro

Ongoing clinical trials by development phase

Loading...

Key Completed Trials

Pro

Completed studies with published results, ranked by significance

Loading...
📊

Trial Timeline

Full development history with FDA approval milestones

|
Loading...
Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

ACYCLOVIR FDA Label Details

Indications & Usage

FDA Label (PDF)

ACYCLOVIR is indicated for the treatment of Herpes Zoster; Genital Herpes; Chickenpox.

Looking for the branded version?

XERESE

Full clinical data, patents, trials, and competitive landscape for acyclovir.

See XERESE

Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.