Helicase-primase inhibitors for the treatment of herpes simplex virus infections - patent evaluation of WO2023/225162 from Gilead Sciences Inc.

Helicase-primase is an interesting target for small-molecule therapy of herpes simplex virus (HSV) infections. With amenamevir already approved for varicella-zoster virus and herpes simplex in Japan and with pritelivir's granted breakthrough therapy designation for the treatment of acyclovir-resistant HSV infections in immunocompromised patients, the target has sparked interest in helicase-primase inhibitors (HPIs). Here, we analyze the first patent application from Gilead in this field, which pursued a me-too approach combining elements from an old Bayer together with a recent Medshine HPI application (which covers the Phaeno Therapeutics drug candidate HN0037). The asset was contributed to Assembly Biosciences, where it is under development as ABI-1179 at the investigational new drug (IND) enabling stage for high-recurrence genital herpes. A structure proposal for indolinoyl derivative ABI-1179 is presented, showing its potential opportunities and limitations compared to other HPIs.

Genital Herpes.

This JAMA Insights examines the history, diagnosis, prevention, and stigma of genital herpes infection in the US and explores treatments such as suppressive therapy.

Atypical presentation of herpes simplex virus 2 primary infection: a case report.

BACKGROUND: Cervicitis, an infectious or noninfectious inflammation of the cervix, encompasses a wide range of clinical conditions, from asymptomatic infections to severe lesions, making its diagnosis difficult. Acute cervicitis may develop into pelvic inflammatory disease. In patients with cervicitis, current guidelines recommend testing for herpes simplex virus when external genital lesions are present. Here, we present the case of a patient with an atypical primary herpes simplex virus 2 infection manifesting as cervicitis without genital lesions. CASE PRESENTATION: A 29-year-old Caucasian woman was hospitalized for pelvic inflammatory disease. The patient complained of severe suprapubic pain, fever, and heavy vaginal discharge. The external genitalia were unremarkable, so empirical antibiotic treatment was initiated. Despite 48 hours of well-administered antibiotic therapy, her complaints persisted. Polymerase chain reaction for possible microbial causes was negative for Chlamydia trachomatis and Neisseria gonorrhoeae. There was no bacterial vaginosis. Repeat gynecological examinations with endovaginal ultrasound revealed an enlarged cervix, and pelvic magnetic resonance imaging supported a diagnosis of cervicitis. At this point, additional screening for other sexually transmitted infections and infectious disease-related etiologies of cervicitis was performed, and the polymerase chain reaction analysis of newly isolated samples was positive for herpes simplex virus 2. No antiviral treatment was initiated given the delay in diagnosing herpes simplex virus 2 infection and the slow but spontaneous abatement of symptoms. CONCLUSION: Herpes simplex virus infection should be considered as a possible cause of cervicitis, even in the absence of typical genital lesions. Early detection of herpes simplex virus allows early treatment, helping to reduce the duration and severity of symptoms and therefore potentially reducing recurrences and improving disease control. These data and data from future cases might spur changes in the guidelines on cervicitis testing and treatment.

Targeting Peptidylarginine Deiminase 3 to Efficiently Suppress Herpes Simplex Virus Type 2 Infection.

Protein expression is regulated through multiple mechanisms, including post-translational modifications (PTMs), which can alter protein structure, stability, localization, and function. Among these, citrullination stands out due to its ability to convert arginine residues into citrulline, altering protein charge and mass. This modification is catalyzed by calcium-dependent protein arginine deiminases (PADs), enzymes implicated in various inflammatory diseases. We have recently shown that human cytomegalovirus (HCMV) and herpes simplex virus type 1 (HSV-1) exploit these enzymes to enhance their replication capabilities. Although the role of PADs in HCMV and HSV-1 infections is well documented, their involvement in HSV-2 infection has not yet been thoroughly investigated. Here, we demonstrate that HSV-2 manipulates the overall protein citrullination profile by activating three PAD isoforms: PAD2, PAD3, and PAD4. However, as previously observed during HSV-1 infection, PAD3 is the most significantly upregulated isoform, both at the mRNA and protein levels. Consistently, we demonstrate that inhibiting PAD3, either through the specific inhibitor CAY10727 or via CRISPR/Cas9-mediated gene silencing, markedly reduces HSV-2 replication and viral protein expression. Lastly, we show that CAY10727 displays an IC50 value of 0.3 µM, which is extremely close to what was previously observed for HSV-1. Overall, our findings highlight the crucial role of PAD3 in the life cycle of HSV-2 and suggest that the targeted inhibition of PAD3 may represent a promising approach for treating HSV-2 infections, especially in cases resistant to existing antiviral therapies.

A case report: recurrent anemia related to long term acyclovir use in a pregnant HIV infected Ugandan.

This case report describes a pregnant patient with recent diagnosis of Human Immuno-Deficiency Virus (HIV) infection initiated on Anti-Retroviral Therapy (ART) in the second trimester, as well as high dose acyclovir high for large infected genital warts. She had no other HIV related opportunistic infections, and no prior anti tuberculosis treatment or preventive medication. Despite little response to acyclovir, patient was continuing on acyclovir for over 4 months. She subsequently developed recurrent anemia requiring frequent transfusion (14 units in total) over a 6-week period. On stopping acyclovir, the anemia subsided, a few weeks later she had a normal delivery, followed by surgical removal of the warts. At a follow-up 8 months later, she was well, with a healthy baby, and reported no other episodes of blood transfusion.

The Topical Novel Formulations of Interferon α-2в Effectively Inhibit HSV-1 Keratitis in the Rabbit Eye Model and HSV-2 Genital Herpes in Mice.

Herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) are widespread human pathogens that establish chronic latent infections leading to recurrent episodes. Current treatments are limited, necessitating the development of novel antiviral strategies. This study aimed to assess the antiviral efficacy of novel topical formulations containing interferon alpha-2b (IFN α-2b) against HSV-1 and HSV-2. The formulations, Oftalmoferon® forte (eye drops) and Interferon Vaginal Tablets, demonstrated potent antiviral effects against HSV-1 and HSV-2 in Vero cells, respectively, with concentration-dependent inhibition of viral replication. Subsequently, their efficacy was tested in animal models: HSV-1 keratitis in the rabbit eye model and HSV-2 genital herpes in mice. Oftalmoferon® forte effectively treated HSV-1 keratitis, reducing clinical symptoms and ulcerations compared to virus control. Interferon Vaginal Tablets showed promising results in controlling HSV-2 genital herpes in mice, improving survival rates, reducing clinical signs, weight loss and viral replication. The novel IFN α-2b formulations exhibited significant antiviral activity against HSV infections in cell culture and animal models. These findings suggest the potential of these formulations as alternative treatments for HSV infections, particularly in cases resistant to current therapies. Further studies are warranted to optimize treatment regimens and assess clinical efficacy in humans.

Prevalence of Genital Herpes and Antiviral Treatment.

BACKGROUND: Genital herpes is a common sexually transmitted infection caused by the herpes simplex virus. Contemporary US population-based epidemiologic data on genital herpes are limited. This study aimed to provide nationally representative estimates of genital herpes prevalence and treatment using a large US health insurance claims database. METHODS: This observational cohort study used administrative claims data from HealthVerity. Crude and age- and sex-standardized prevalence rates of genital herpes and recurrent genital herpes were calculated for the years 2019 to 2021. The distribution of patients with prevalent genital herpes who received episodic or suppressive antiviral therapy was also estimated. RESULTS: From 2019 to 2021, the standardized prevalence of genital herpes and recurrent genital herpes ranged from 236 to 280 cases per 100,000 person-years and 81 to 98 cases per 100,000 person-years, respectively. The prevalence of genital herpes was highest among those aged 25 to 29 years (prevalence range, 497-582 years), female patients (prevalence range, 348-404 years), and those with a history of HIV infection (prevalence range, 1608-2080 years). The prevalence of recurrent genital herpes was also highest in these groups. From 2019 to 2021, two-thirds of patients (65%-68%) with prevalent genital herpes received antiviral medications; the majority received episodic therapy (80%) rather than suppressive therapy (20%). CONCLUSIONS: The burden of genital herpes and recurrent genital herpes in the United States is substantial, with the highest rates observed in young adults, women, and immunocompromised individuals. About two-thirds receive antiviral treatment each year.

Herpes Simplex Virus: A Practical Guide to Diagnosis, Management, and Patient Counseling for the Primary Care Clinician.

Genital herpes is a chronic, lifelong sexually transmitted viral infection, which can cause recurrent, self-limited genital ulcers. It is caused by herpes simplex virus (HSV) type 1 and type 2 viruses. Genital HSV infection is a very prevalent STI, which causes self-limited, recurrent genital ulcers. Treatment decreases duration of symptoms and signs and can be provided as episodic or suppressive therapy. Genital herpes can have a substantial impact during pregnancy and on sexual health in general. Counseling on natural history, transmission, treatment, and management of sexual partners is an integral part of management of genital herpes.

Korean sexually transmitted infection guidelines 2023 revision, guideline update of viral infections: Genital herpes and anogenital warts.

The Korean Association of Urogenital Tract Infection and Inflammation and the Korea Disease Control and Prevention Agency regularly update, revise, and develop new content for the Korean sexually transmitted infection (STI) guidelines. These professional bodies respond to changing epidemiological trends and evolving scientific evidence, and consider advances in laboratory diagnostics and research. The principal recommendations of the 2023 Korean STI guidelines in terms of viral infection follow: 1) If genital herpes recurs more than 4-6 times annually, suppressive therapy with acyclovir 400 mg orally 2 times/day or famciclovir 250 mg orally 2 times/day or valacyclovir 500 mg orally once a day (for patients with <10 episodes/year) or valacyclovir 1 g orally once daily (for patients with ≥10 episodes/year) is recommended to prevent recurrence; 2) molecular human papillomavirus (HPV) testing is not recommended as a routine test for STI status, nor for determination of HPV vaccination status; and 3) patients should inform their current sexual partners about anogenital warts because the types of HPV that cause such warts can be passed to partners. These guidelines will be updated every 5 years and will be revised when new knowledge on STIs becomes available and there is a reasonable need to improve the guidelines. Physicians and other healthcare providers can use the guidelines to assist in the prevention and treatment of STIs.

Recalcitrant ulcerative genital herpes in an immunocompetent individual treated successfully with imiquimod.

BACKGROUND: This case report describes the successful use of imiquimod to treat genital herpes in an immunocompetent individual with acyclovir-resistant HSV. CASE REPORT: A 32 year old male patient, presented with asymptomatic non-healing ulcers over the genital region for 2 years. The ulcers initially responded to acyclovir but became persistent after a few months. He also received multiple courses of antibiotics. On examination, the patient had bilateral inguinal lymphadenopathy and multiple painless ulcers over the coronal sulcus. Routine investigations were normal. The patient was treated with oral and intravenous acyclovir but showed no response. He was then started on topical imiquimod cream applied on alternate days. After one week, the patient presented with pain, redness, burning sensation, and fresh ulcer over the glans which were suspected to be imiquimod-induced irritant reaction or ulcer. Imiquimod was withheld for one week and then restarted at a twice-weekly schedule. After 1 month and 7 days of treatment with imiquimod at a twice-weekly schedule, there was healing of the ulcers. CONCLUSION: This case report illustrates the efficacy of imiquimod cream as a topical treatment for genital herpes simplex in an immunocompetent patient who had previously been unresponsive to treatment with acyclovir.

Oral Self-Nanoemulsifying System Containing Ionic Liquid of BX795 Is Effective against Genital HSV-2 Infection in Mice.

BX795 is an emerging drug candidate that has shown a lot of promise as a next-generation non-nucleoside antiviral agent for the topical treatment of herpes simplex virus type-1 (HSV-1) and herpes simplex virus type-2 (HSV-2) infections. Our studies indicated that BX795 has limited oral bioavailability, which could be attributed to its low and pH-dependent solubility. Lipid-based formulations such as self-nanoemulsifying systems (SNESs) can improve the solubility and oral bioavailability of BX795, but the poor lipid solubility of BX795 further limits the development of SNES. To improve the loading of BX795 into SNES, we evaluated the ability of various bulky and biocompatible anions to transform BX795 into an ionic liquid (IL) with higher lipid solubility. Our studies showed that sodium lauryl sulfate and docusate sodium were able to transform BX795 into IL. Compared to pure BX795, the developed BX795 ILs showed differential in vitro cytocompatibility to HeLa cells but exhibited similar in vitro antiviral activity against HSV-2. Interestingly, BX795 docusate (BX795-Doc), an IL of BX795 with ∼135-fold higher lipid solubility than pure BX795, could be successfully incorporated into an SNES, and the developed BX795-Doc-SNES could readily form nanoemulsions of size ≤200 nm irrespective of the pH of the buffer used for dilution. Our in vitro studies showed that BX795-Doc-SNES retained the inherent antiviral activity against HSV-2 and showed similar in vitro cytocompatibility, indicating the availability of BX795 from the SNES in vitro. Finally, orally delivered SNES containing BX795-Doc showed a significant reduction in HSV-2 infection in mice compared to the untreated control. Thus, the transformation of BX795 into IL and the subsequent incorporation of the BX795 IL into the SNES are an effective strategy to improve oral therapy of genital herpes infection.

The Evaluation and Treatment of an Infant Exposed to Nongenital HSV-2: A Case Report.

BACKGROUND: Pregnant persons with a primary genital herpes simplex virus (HSV) infection can transfer HSV to the fetus or infant through the placenta or birth canal, which can cause significant infant morbidity or mortality. Primary nongenital infections with HSV-1 or HSV-2 in pregnant persons and the risk of infant infection are not well documented, leaving the clinician to make non-evidence-based decisions on evaluation and treatment in such presentations. CLINICAL FINDINGS: A term newborn was delivered vaginally by a pregnant person with a nongenital HSV-2 infection. The pregnant person's rash first appeared around 32 weeks' gestation, started on their lower back, and terminated on the outer left hip. The rash improved but was still present at time of delivery, and this rash was their first known HSV outbreak. PRIMARY DIAGNOSIS: Prenatal exposure to HSV-2. INTERVENTIONS: Diagnostics included the pregnant person's rash surface culture, immunoglobulin G and immunoglobulin M for HSV-1 and -2; infant surface, cerebral spinal fluid (CSF), and serum HSV-1 and HSV-2 polymerase chain reactions (PCRs), infant CSF studies, blood culture, liver function tests, and treatment with intravenous acyclovir. OUTCOMES: This infant remained clinically well during hospitalization and was discharged home at 5 days of life when CSF, surface, and serum PCRs resulted negative. PRACTICE RECOMMENDATIONS: Risk for infant HSV infection versus parent/infant separation and exposure to invasive procedures and medications should be considered when pregnant persons present with primary versus recurrent nongenital HSV infections. Research is needed for the evaluation and treatment of infants born to pregnant persons with primary nongenital HSV infections in pregnancy.

Understanding the Medical Dictionary for Regulatory Activities (MedDRA) reporting of herpes simplex virus (HSV) adverse events in atopic dermatitis clinical trials.

Drug efficacy is best evaluated by randomized, controlled, double-blind clinical trials; however, safety is harder to assess. The Medical Dictionary for Regulatory Activities (MedDRA) is used to track and categorize adverse events (AE) during clinical trials. Recent atopic dermatitis (AD) clinical trials were reviewed to illustrate how an understanding of MedDRA may be helpful when evaluating the rates and nature of adverse events related to herpes simplex virus (HSV) infection. All completed AD clinical trials (excluding phase I studies) with results on clinicaltrials.gov (01/01/2018-01/31/2023) were queried in January 2023. MedDRA version, preferred term (PT) for AEs captured as "HSV", PTs for other AEs possibly related to HSV, frequency thresholds for reporting non-serious AEs, and route of treatment were recorded. Of the 46 clinical trials, 17 had PTs for AEs captured as "HSV". Among all studies, 11 different versions of MedDRA were utilized, from versions 10 to 24.1. In all studies, PTs for AEs captured as "HSV" were listed in the Infections and Infestations system organ class (SOC) classification of MedDRA. PTs varied from "herpes simplex", "herpes virus infection", "herpes ophthalmic", "ophthalmic herpes simplex", "nasal herpes", "oral herpes", "herpes dermatitis", "eczema herpeticum", "genital herpes simplex", and "genital herpes." While one clinical trial of dupilumab (NCT03359356) simply reported the PT "oral herpes" as an AE, a clinical trial of DS107 (NCT03817190) reported the PTs "oral herpes", "herpes simplex", and "herpes virus infection" separately. In the DS107 clinical trial, it is unclear if the same adverse event was reported under multiple PTs or if multiple HSV-related AEs occurred. Although the definition of HSV is unchanged from 2018 to 2023 and there are few changes between MedDRA versions, coding for HSV is complex. HSV events can be reported in different ways, which may impact the interpretation of a drug's safety profile.

The Interplay of Genital Herpes with Cellular Processes: A Pathogenesis and Therapeutic Perspective.

Genital herpes, primarily caused by herpes simplex virus-2 (HSV-2), remains a pressing global health concern. Its remarkable ability to intertwine with cellular processes, from harnessing host machinery for replication to subverting antiviral defenses like autophagy and programmed cell death, exemplifies the intricate interplay at the heart of its pathogenesis. While the biomedical community has extensively researched antiviral interventions, the efficiency of these strategies in managing HSV-2 remains suboptimal. Recognizing this, attention has shifted toward leveraging host cellular components to regulate HSV-2 replication and influence the cell cycle. Furthermore, innovative interventional strategies-including drug repurposing, microbivacs, connecting the host microbiome, and exploiting natural secondary metabolites-are emerging as potential game changers. This review summarizes the key steps in HSV-2 pathogenesis and newly discovered cellular interactions, presenting the latest developments in the field, highlighting existing challenges, and offering a fresh perspective on HSV-2's pathogenesis and the potential avenues for its treatment by targeting cellular proteins and pathways.

Epigallocatechin Gallate-Modified Silver Nanoparticles Show Antiviral Activity against Herpes Simplex Type 1 and 2.

(1) Background: Epigallocatechin gallate (EGCG) has been recognized as a flavonoid showing antiviral activity against various types of DNA and RNA viruses. In this work, we tested if EGCG-modified silver nanoparticles (EGCG-AgNPs) can become novel microbicides with additional adjuvant properties to treat herpes infections. (2) Methods: The anti-HSV and cytotoxic activities of EGCG-AgNPs were tested in human HaCaT and VK-2-E6/E7 keratinocytes. HSV-1/2 titers and immune responses after treatment with EGCG-AgNPs were tested in murine models of intranasal HSV-1 infection and genital HSV-2 infection. (3) Results: EGCG-AgNPs inhibited attachment and entry of HSV-1 and HSV-2 in human HaCaT and VK-2-E6/E7 keratinocytes much better than EGCG at the same concentration. Infected mice treated intranasally (HSV-1) or intravaginally (HSV-2) with EGCG-AgNPs showed lower virus titers in comparison to treatment with EGCG alone. After EGCG-AgNPs treatment, mucosal tissues showed a significant infiltration in dendritic cells and monocytes in comparison to NaCl-treated group, followed by significantly better infiltration of CD8+ T cells, NK cells and increased expression of IFN-α, IFN-γ, CXCL9 and CXCL10. (4) Conclusions: Our findings show that EGCG-AgNPs can become an effective novel antiviral microbicide with adjuvant properties to be applied upon the mucosal tissues.