Vaccine Info

Pritelivir (AIC316) Herpes Treatment 2023

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Last reviewed
June 24, 2023
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Robert Carlson, MD

Pritelivir (AIC316) Herpes Treatment June 2023

AiCuris Anti-infective Cures AG Pritelivir is a highly potent inhibitor of Herpes Simplex Virus (HSV) replication that belongs to a new chemical class and acts via a novel mechanism of action (inhibition of the viral helicase-primase enzyme complex), in contrast to currently used nucleoside analogues. The discovery of pritelivir resulted from systematic research rather than an accidental discovery. Pritelivir does not require activation by viral enzymes and can thus protect uninfected cells.

AiCuris develops Pritelivir oral tablets for the treatment of acyclovir-resistant mucocutaneous HSV infections. As an active ingredient in a new chemical class (thiazolylamides), pritelivir is active against both HSV (HSV-1 and HSV-2) types that cause genital or cold sores. In addition, Pritelivir is also effective against viruses resistant to commercially available drugs.

On December 20, 2016, The JAMA Network published an Original Investigation reporting a double-blind, randomized crossover phase 2 clinical study of 91 adults with recurrent genital herpes, the percentage of genital swabs with HSV detected over 28 days was significantly lower during the use of pritelivir than the use of valacyclovir (2.4% vs. 5.3%).

On March 1, 2023, an Original Article reviewed - First-in-Human, Single- and Multiple-Ascending-Dose, Food-Effect, and Absolute Bioavailability Clinical Trials to Assess the Pharmacokinetics, Safety, and Tolerability of Pritelivir, a Nonnucleoside Helicase-Primase Inhibitor Against Herpes Simplex Virus in Healthy Subjects. This sponsored study concluded: Considering a therapeutic dose of 100 mg once daily, pritelivir demonstrated a favorable safety, tolerability, and pharmacokinetic profile in healthy subjects to support further development.

A phase 3 trial in immunocompromised patients is ongoing. The last Update was Posted on March 24, 2023; the Estimated Primary Completion Date is June 2024. Pritelivir received the U.S. Food and Drug Administration (FDA) Breakthrough Therapy Designation on June 5, 2020.

AiCuris is a clinical-stage biopharmaceutical company founded in 2006 in Wuppertal, Germany, as a spin-off from Bayer and focuses on the discovery and development of drugs targeting infectious diseases.

Herpes Testing 2023

Ulta Lab offers confidential herpes tests in June 2023.

Pritelivir Availability 2023

As of June 23, 2023, Pritelivir is unavailable as a marketed product. However, AiCuris supports expanded access requests for Pritelivir oral tablets to treat eligible patients and collaborates with myTomorrows to facilitate early access to Pritelivir for acyclovir-resistant mucocutaneous HSV infections in immunocompromised patients. Expanded Access Programs (EAP) offer an ethical, compliant, and controlled way of providing treatment with a medicine not licensed in a patient's country of residence. Eligible patients for an EAP are in high medical need, cannot participate in a Clinical Trial, and have exhausted all registered treatment options. More information can be requested here.

Pritelivir Indication

Pritelivir is being developed to treat acyclovir-resistant and dual-resistant (resistant to acyclovir and intolerant or resistant to foscarnet) HSV infections. HSV is a common and contagious virus; most adults and pediatric patients are HSV seropositive. The WHO says an estimated 3.7 billion people under age 50 (67%) have HSV-1 infection globally, and about 491 million people aged 15–49 (13%) worldwide have HSV-2 infection.

Herpes Treatments

Other herpes treatment news is posted at this link

Herpes Vaccines

Herpes vaccine candidates are conducting clinical trials.

Pritelivir News 2023

March 1, 2023 - A study disclosed Pritelivir was evaluated in multiple clinical studies.

October 6, 2022 - ACS Publications: Discovery, Chemistry, and Preclinical Development of Pritelivir, a Novel Treatment Option for Acyclovir-Resistant Herpes Simplex Virus Infections.

September 29, 2022 - AiCuris Anti-infective Cures AG announced the opening of the third round of its AiCubator corporate innovation accelerator initiative.

June 14, 2022 - AiCuris Anti-infective Cures AG announced the opening of its ongoing international Phase 2/3 clinical trial, PRIOH- 1. The study evaluates the efficacy and safety of oral pritelivir compared to standard intravenous foscarnet therapy.

July 8, 2021 - AiCuris Anti-infective Cures AG announced the start of pivotal phase 3 development with its proprietary lead compound pritelivir, a novel helicase-primase inhibitor, following encouraging phase 2 interim results achieved in the phase 2 part of its clinical phase 2/3 trial, PRIOH-1.

June 5, 2020 - "The decision by the FDA to grant Breakthrough Therapy designation for oral pritelivir underscores the potential of our product to fill the major need for innovative, more efficacious therapies for immunocompromised patients with HSV infections that have become resistant to standard treatments," said Dr. Holger Zimmermann, CEO of AiCuris Anti-infective Cures GmbH. "Pritelivir already has shown clinically that it has the potential to become an important alternative to current treatments as a highly effective and convenient oral therapy. The Breakthrough Therapy designation should enable us to further accelerate the development of this compound."

December 20, 2016 - The JAMA Network published: Effect of Pritelivir Compared With Valacyclovir on Genital HSV-2 Shedding in Patients With Frequent RecurrencesA Randomized Clinical Trial. Conclusions and Relevance  Among adults with frequently recurring genital HSV-2, the use of pritelivir compared with valacyclovir resulted in a lower percentage of swabs with HSV detection over 28 days. Further research is needed to assess longer-term efficacy and safety.

January 16, 2014 - Medscape wrote: Pritelivir May Be Effective and Safe Against Genital Herpes.

July 2004 - Discovery, SAR and Medicinal Chemistry of Herpesvirus Helicase Primase Inhibitors.

April 2002 - New helicase-primase inhibitors as drug candidates for treating herpes simplex disease.

Pritelivir Clinical Trials

The PRIOH-1 multi-center open-label Phase 3 trial evaluates the efficacy and safety of orally administered pritelivir for treating acyclovir-resistant mucocutaneous HSV infections in immunocompromised patients. In the second part of the trial, conducted at 20 sites in the U.S., 22 immunocompromised patients with acyclovir-resistant mucocutaneous HSV infections were randomized (2:1) to receive over up to 28 days either oral pritelivir or intravenously administered foscarnet, a virostatic agent which is mainly used for the treatment of herpes virus infections resistant to other antiviral drugs. In addition, eight immunocompromised patients with acyclovir-resistant mucocutaneous HSV infections who showed resistance or intolerance to foscarnet were also treated with pritelivir over up to 28 days. Based on the investigator's assessment, pritelivir treatment showed a very good cure rate of 93.3% in acyclovir-resistant infections. Moreover, in difficult-to-treat patients with minimal treatment options due to acyclovir resistance and foscarnet resistance or intolerance, pritelivir showed good efficacy within 28 days.

Phase 2 Study HIC#: 2000021054 - Trial on Efficacy and Safety of Pritelivir Tablets for Treatment of Acyclovir-resistant Mucocutaneous HSV (Herpes Simplex Virus) Infections in Immunocompromised Adults (PRIOH-1).

This Phase 1 clinical trial is a double-blind, single-center, randomized, placebo- and positive-controlled, parallel-group, 'nested crossover' trial with multiple oral dose administration of pritelivir or matching placebo as well as a single oral administration of moxifloxacin (positive control) and corresponding matching placebo in healthy male and female subjects. Last Update Posted: January 4, 2023.

Clinical Trials

No clinical trials found