acyclovir / Generic mfg. - LARVOL DELTA

Pritelivir Demonstrated Superior Efficacy Compared to Investigator’s Choice Treatment for Refractory Herpes Simplex Virus Infections In Immunocompromised Patients: PRIOH-1, Phase 3 Safety and Efficacy (TCT-ASTCT-CIBMTR 2026) - "Introduction Pritelivir is a novel oral helicase-primase inhibitor, active against HSV-1 and HSV-2, including strains resistant to nucleoside analogues and foscarnet.ObjectivesPRIOH-1 evaluated the safety and efficacy of pritelivir vs. investigator’s choice therapy (ICT) in immunocompromised (IC) patients with refractory herpes simplex virus (HSV) infection, with or without resistance (R±R).MethodsIn this randomized (1:1), controlled, open label trial, 101 IC patients (≥16 years) with R±R HSV mucocutaneous infection received oral pritelivir (100 mg daily; 400 mg loading dose) or ICT (IV foscarnet, IV/topical cidofovir, or topical imiquimod) for up to 28 days, extendable to 42 days. Eligibility criteria included hematopoietic cell transplant, solid organ transplant, HIV, malignancy, or chronic use of immunosuppressive treatment with refractory/clinical failure (defined as no clinical improvement of lesions after ≥7 days of standard of care nucleoside analogue..."

Clinical • Late-breaking abstract • P3 data • Herpes Simplex • Human Immunodeficiency Virus • Immunology • Infectious Disease • Primary Immunodeficiency • Solid Organ Transplantation

Host-directed novel mechanistic insights of doxorubicin reveal its efficacy against drug-resistant HSV-1 underscoring risks with oncolytic virotherapy. (PubMed, Drug Resist Updat) - "This study identifies PI3K-AKT pathway inhibition as a novel host-directed antiviral mechanism underlying doxorubicin's activity against HSV-1, demonstrates its synergistic potential with nucleoside analogs, and provides mechanistic insight into raising concerns over oncolytic HSV-based therapies. Collectively, these findings highlight the potential of localized, host-targeted strategies for managing drug-resistant HSV-1 infections."

Journal • Herpes Simplex • Infectious Disease • Ocular Infections • Oncology • Ophthalmology

Rash, encephalopathy, and aciclovir: was aciclovir the cause or the needed treatment? (ESCMID Global 2026) - No abstract available

CNS Disorders

Amenamevir for acyclovir-resistant genital HSV-2 infection in people living with HIV (ESCMID Global 2026) - No abstract available

Human Immunodeficiency Virus • Infectious Disease

Helicase-primase inhibitor adibelivir (IM-250) shows potent antiviral activity against HSV clinical and acyclovir-resistant isolates and achieves therapeutic exposure in phase I/Ib studies (ESCMID Global 2026) - No abstract available

Clinical • P1 data

Natural polymorphisms in UL23 thymidine kinase of herpes simplex virus type 1 associated with a decreased susceptibility to acyclovir (ESCMID Global 2026) - No abstract available

Herpes Simplex

Dual Pathology or Infectious Trigger? Coexisting Varicella Zoster Virus Myelitis and Aquaporin-4 Positivity in an Elderly Patient After Radiation Therapy (ACTRIMS Forum 2026) - "The patient was started on intravenous acyclovir for presumed VZV myelitis, followed by a five-day course of high-dose IV methylprednisolone and plasma exchange for suspected NMOSD. The coexistence of VZV and AQP4 positivity supports emerging evidence that viral infections—especially herpesviruses—may trigger or unmask NMOSD in predisposed individuals. Recognition of such overlap is essential to guide early combined antiviral and immunomodulatory therapy. Also, radiation may have contributed by releasing AQP4 antigens from astrocytic or vascular injury, thereby amplifying antibody-mediated inflammation characteristic of NMOSD."

Clinical • Bladder Cancer • CNS Disorders • Genito-urinary Cancer • Herpes Zoster • Immunology • Infectious Disease • Neuromyelitis Optica Spectrum Disorder • Rare Diseases • Solid Tumor • Varicella Zoster

Atypical Presentations of HSV Encephalitis in a Case of Hypogammaglobulinemia, Reactive Viral Injury vs Parainfectious Encephalitis? (ACTRIMS Forum 2026) - "After no clinical improvement with acyclovir treatment, further work up revealed pan-hypogammaglobulinemia (CVID) and he was started on IVIG... Immunocompromised patients with HSV-1 encephalitis often show fewer prodromal symptoms but more widespread brain involvement due to impaired viral control, and they may lack CSF pleocytosis. In our patient, lack of clinical improvement despite antiviral therapy, worsening MRI findings, CSF pleocytosis with elevated protein, and severe hypogammaglobulinemia suggested an autoimmune or T-cell-mediated encephalitis. The patient did improve after immunotherapy with IVIG and corticosteroids."

Clinical • IO biomarker • CNS Disorders • Epilepsy • Hematological Disorders • Herpes Simplex • Immunology • Infectious Disease • Inflammation • Primary Immunodeficiency • Vasculitis • CD2 • CD4 • CD5 • CD8

Chimeric Antigen Receptor T Cell (CAR-T) Immunotherapy for ProgressivePhenotypes of Multiple Sclerosis: ongoing results from a prospective Phase 1, Open-Label, Single CenterStudy of an Autologous Fully-Human Anti-CD19 CAR-T (ACTRIMS Forum 2026) - "Two experienced transient shingles reactivation, resolving with oral acyclovir. Autologous CD19-directed CAR T-cell therapy (KYV-101) in progressive MS was feasible, well tolerated, and induced profound yet reversible B-cell depletion. B cell reconstitution skewed strongly toward a naïve phenotype. Early clinical signals included improved fatigue, iADLs, and EDSS, with varied intrathecal biomarker shifts."

CAR T-Cell Therapy • Clinical • IO biomarker • P1 data • CNS Disorders • Hematological Disorders • Herpes Zoster • Infectious Disease • Inflammation • Multiple Sclerosis • Pneumonia • Tetanus • Varicella Zoster • CD27

Sudden Sensorineural Hearing Loss as the Presenting Symptom of Varicella Zoster Virus Rhombencephalitis: A Case Report. (PubMed, Cureus) - "Lumbar puncture detected varicella zoster virus (VZV) encephalitis, and the patient was treated with intravenous acyclovir...Follow-up MRI showed near-complete lesion resolution, and his hearing showed minor improvement. This case demonstrates how expedient MRI can detect unusual causes of sudden SNHL, enabling timely management and increasing the likelihood of resolution."

Journal • CNS Disorders • Herpes Zoster • Inflammation • Otorhinolaryngology • Varicella Zoster

Congenital CMV Infection: Determination of Transplacental Passage of Aciclovir by Ex Vivo Placental Perfusion. (PubMed, BJOG) - "The transplacental transfer of aciclovir is low. Despite aciclovir's low molecular weight and hydrophilicity, moderate plasma protein binding and rapid renal elimination may limit placental availability, and the observed transfer was lower than expected for passive diffusion, suggesting involvement of facilitated uptake or efflux mechanisms. These results support the current rationale for high-dose valaciclovir regimens in pregnancy and suggest a potential role for transporter-mediated drug transfer."

Journal • Preclinical • Cytomegalovirus Infection • Infectious Disease

When confusion abounds: guideline adherence in the investigation and management of encephalitis in Sydney, Australia. (PubMed, Intern Med J) - "Guideline application was variable, with areas identified for improvement. Prospective studies are needed to investigate guideline-adherence barriers."

Journal • CNS Disorders • Herpes Simplex • Human Immunodeficiency Virus • Infectious Disease • Inflammation

Allosteric targeting with antiviral nucleotide analogues allows fine-tuning of SAMHD1 dNTPase activity. (PubMed, J Biol Chem) - "Using a variety of biochemical and biophysical assays, we demonstrate that the antiviral guanine nucleotide analogues acyclovir- and ganciclovir-triphosphate are potent AS1 binders that induce the formation of enzymatically competent SAMHD1 tetramers, however with reduced enzymatic activity. Furthermore, based on an apparent synergistic activation between these nucleotide analogues and the physiological AS1 activator GTP, we also propose the existence of mixed-occupancy SAMHD1 tetramers. Our work therefore provides new insights into the allosteric activation and oligomerisation process of SAMHD1 and opens new avenues to pharmacologically control the dNTPase activity utilising non-natural allosteric ligands."

Journal • Oncology

Eco-friendly biosynthesis of manganese oxide-silver bimetallic nanoparticles using Cucumis melo peel extract: characterization, antioxidant, antimicrobial, and antiviral activities. (PubMed, Bioresour Bioprocess) - "Moreover, the inhibition rates achieved against the tested virus were 73% for MnO-Ag BNPs and 99% for acyclovir. These outcomes highlight the potential of MnO-Ag BNPs as promising candidates for biomedical and antiviral applications."

Journal • Herpes Simplex

Initial diagnosis of herpes zoster ophthalmicus complicated by central retinal artery occlusion and subsequent varicella-zoster virus encephalitis: a case report. (PubMed, Front Neurol) - "A 65-year-old male with HZO who underwent intravenous acyclovir treatment complained of sudden onset blurry vision of his left eye...There were only a few cases reported to have CRAO after diagnosed HZO. This cause of viral-related CRAO led to a complicated treatment decision."

Journal • CNS Disorders • Herpes Zoster • Ophthalmology • Retinal Disorders • Varicella Zoster

Neurotoxicity from acyclovir and valacyclovir in patients undergoing peritoneal dialysis: Still rare, but still present. (PubMed, Perit Dial Int) - "Despite decades of clinical experience and numerous reports, acyclovir and valacyclovir-induced neurotoxicity continue to occur in patients with severe renal impairment. This report underscores the importance of dose adjustment and close monitoring, emphasizing that neurotoxicity, although rare, can occur even at apparently safe doses in patients undergoing peritoneal dialysis."

Journal • Anorexia • Ataxia • Chronic Kidney Disease • Herpes Zoster • Infectious Disease • Movement Disorders • Nephrology • Psychomotor Agitation • Renal Disease • Varicella Zoster

Risk factors for acute kidney injury associated with intravenous acyclovir in older adults: ACICLOAGED study. (PubMed, Maturitas) - "In adults aged 75 years or more treated with intravenous acyclovir for suspected meningoencephalitis, frailty was a strong and independent predictor of acute kidney injury, whereas chronological age and baseline renal function were not. Incorporating frailty assessment into clinical decision-making may help identify patients at higher risk and guide preventive strategies."

Journal • Acute Kidney Injury • CNS Disorders • Nephrology • Renal Disease

Marine Derived Natural Products: Emerging Therapeutics Against Herpes Simplex Virus Infection. (PubMed, Biomolecules) - "Despite decades of clinical reliance on nucleoside analogues such as acyclovir, the therapeutic landscape has stagnated with rising antiviral resistance, toxicity associated with prolonged use, and the complete inability of current drugs to eliminate latency or prevent reactivation continue to undermine effective disease control...This review integrates emerging evidence on structural diversity, mechanistic breadth, and translational promise of marine natural products with anti-HSV activity. Collectively, these advances position marine-derived compounds as powerful, untapped scaffolds capable of reshaping the future of HSV therapeutics."

Journal • Review • CNS Disorders • Gastroenterology • Herpes Simplex • Human Immunodeficiency Virus • Immunology • Infectious Disease • Inflammatory Bowel Disease • Keratitis • Ocular Inflammation • Ophthalmology • Ulcerative Colitis

Synergistic hyperinflammation in IgA vasculitis complicated by varicella-induced HLH: a case report. (PubMed, Front Immunol) - "A multimodal therapeutic approach that combining high-dose acyclovir, intravenous immunoglobulin (IVIG), therapeutic plasma exchange (TPE), reduced-dose etoposide (75 mg/m²), and dexamethasone achieved rapid disease remission. What's more, lymphocytopenia may be used as a biomarker to assess disease severity and recovery, and this finding emphasizes the need for long-term immune monitoring. This case provides valuable insights into the pathogenesis and management of VZV related HLH in rheumatic and immune diseases."

Journal • Hematological Disorders • Hemophagocytic lymphohistiocytosis • Hepatology • Herpes Zoster • Immunology • Infectious Disease • Inflammation • Liver Failure • Rare Diseases • Varicella Zoster • Vasculitis

Association between Herpes Simplex Virus Serostatus and Non-Relapse Mortality, Relapse, and Relapse-Related Mortality Among Adult Allogeneic Hematopoietic Cell Transplant Recipients (TCT-ASTCT-CIBMTR 2026) - "Prophylaxis was twice daily acyclovir (800mg) or valacyclovir (500mg) for at least one year. HSV-1 seropositive patients had a significantly higher hazard of relapse and RRM compared to seronegative patients, even after accounting for known risk factors for relapse and mortality. Neither HSV-1 nor HSV-2 were associated with NRM. Further studies are needed to better understand this association."

Clinical • Acute Graft versus Host Disease • Bone Marrow Transplantation • Cytomegalovirus Infection • Graft versus Host Disease • Herpes Simplex • Immunology • Transplantation

Paired TCR Sequencing Illustrates Virus-Specific T cell Dynamics after Allogeneic Hematopoietic Stem Cell Transplant (TCT-ASTCT-CIBMTR 2026) - "HSV-specific CD8 + frequency rose during interruptions in acyclovir prophylaxis ( Figure 3C )... Paired αβ-TCR sequencing using TIRTL-seq enables longitudinal analysis at a depth unachievable with other TCR sequencing approaches. Viral-specific T cell donor-to-recipient transfer is trackable, and clonal frequency changes correlate with clinical events. Ongoing work will expand the cohort, assess effects of HLA type, conditioning, and GVHD prophylaxis, and integrate newly identified BK virus-specific TCRs."

Virus specific T cells • Bone Marrow Transplantation • Graft versus Host Disease • Immunology • Infectious Disease • Transplantation • CD4 • CD8

Bilateral Cytomegalovirus Retinitis With Co-infection of Epstein-Barr Virus and Varicella-Zoster Virus: A Rare Case. (PubMed, Cureus) - "The patient was treated with intravenous acyclovir and ganciclovir, followed by intravitreal ganciclovir injections. This case highlights the importance of PCR testing for accurate diagnosis of atypical infectious uveitis. Although rare, concurrent infections with multiple herpesviruses may occur, and coinfection with VZV in particular could be associated with a poorer prognosis."

Journal • Cytomegalovirus Infection • Epstein-Barr Virus Infections • Genetic Disorders • Herpes Zoster • Immunology • Infectious Disease • Inflammation • Inflammatory Arthritis • Ocular Infections • Ocular Inflammation • Ophthalmology • Retinal Disorders • Retinal Vein Occlusion • Rheumatoid Arthritis • Rheumatology • Uveitis • Varicella Zoster

Non-congenital HSV-1 Keratitis in an Immunocompetent 9-Month-Old Infant. (PubMed, J Pediatr Ophthalmol Strabismus) - "Subsequent evaluation revealed HSV-1 keratitis, and the patient was treated with intravenous acyclovir in combination with topical moxifloxacin and topical ganciclovir, resulting in complete resolution of symptoms within one week. This case adds to the limited literature on infantile HSV keratitis and highlights the importance of maintaining a high index of suspicion for HSV infection in infants with corneal involvement. Early recognition and prompt antiviral treatment are critical to preventing vision-threatening complications."

Journal • Conjunctivitis • Herpes Simplex • Infectious Disease • Keratitis • Ocular Infections • Ocular Inflammation • Ophthalmology • Pain

Safety and efficacy of adjunct dexamethasone in adults with herpes simplex virus encephalitis in the UK (DexEnceph): a multicentre, observer-blind, randomised, phase 3, controlled trial. (PubMed, Lancet Neurol) - "In adults with HSV encephalitis, dexamethasone plus aciclovir had a satisfactory safety profile but did not improve verbal memory score compared with aciclovir alone. Given the established role of corticosteroids in other inflammatory encephalitides, our findings suggest that their early use in suspected encephalitis is unlikely to be harmful. Future studies should assess more targeted immunomodulatory approaches in HSV encephalitis."

Clinical • Journal • P3 data • Cardiovascular • CNS Disorders • Epilepsy • Hematological Disorders • Herpes Simplex • Inflammation • Pulmonary Embolism • Respiratory Diseases

Topical aciclovir should not be used in the management of anogenital herpes simplex virus. (PubMed, Int J STD AIDS) - No abstract available

Journal • Herpes Simplex