Herpes Cure
Pipeline 5.0
The fifth edition of our annual report on the antivirals, vaccines and gene therapies in development for herpes simplex virus. See what advanced, what stalled and what the field needs next, with the full recording and every slide from the release event.
Watch the release event
Drs. Jeffrey Klausner, Lao-Tzu Allan-Blitz and Luis Schang presented Pipeline 5.0 live on October 7, 2026, covering research progress, program attrition and priorities for a broader HSV pipeline.
What changed in 2026
Pipeline 5.0 shows both progress and attrition. These are the headlines from this year’s report, each linked to its slide.
Pritelivir is under FDA Priority Review
The most advanced new therapy in Pipeline 5.0. AiCuris’ helicase–primase inhibitor met its Phase 3 primary endpoint in immunocompromised patients with refractory HSV. An FDA decision is expected in Q4 2026.
See slide 24Weekly antivirals are heading to Phase 2
Gilead’s GS-1179 and GS-5366 reduced viral shedding and lesion rates with once-weekly dosing, and GS-5366 also showed antiviral activity with exploratory monthly dosing. GS-1179 is expected to start Phase 2 by the end of 2026.
See slide 26Adibelivir joins BD111 in Phase 2a
Adibelivir, an oral helicase–primase inhibitor active against HSV-1 and HSV-2 (including acyclovir-resistant strains), dosed its first Phase 2a patient in June 2026. BD111, a Cas9 gene-editing therapy for HSV-1 stromal keratitis, has been in Phase 2a since April 2025.
See slide 27An mRNA vaccine shows early immune responses
In interim Phase 1 data, BioNTech’s BNT163 showed acceptable tolerability and produced binding and neutralizing antibodies against HSV-2. The trial is expected to finish in October 2026.
See slide 16Four programs left the pipeline
GSK and Moderna discontinued their therapeutic HSV-2 vaccines after Phase 2 and Phase 1/2. Shanghai BDgene’s preclinical HSV-2 program and Rational Vaccines’ RVX201 no longer meet HCA’s selection criteria because public evidence hasn’t shown enough recent progress.
See slide 17Most antivirals converge on one viral function
Most current and emerging HSV drugs act on viral DNA replication, through the helicase–primase complex or the thymidine kinase and DNA polymerase pathway. A more resilient pipeline needs new biological targets, new chemistry and multiple therapeutic approaches.
See slide 29Pipeline 5.0 is free to read and download.Herpes Cure Advocacy’s volunteer-driven team keeps it that way with support from donors like you.
Pipeline 5.0 release event slides
All 33 slides presented live on October 7, 2026 by Drs. Jeffrey Klausner, Lao-Tzu Allan-Blitz and Luis Schang. Use the arrows, your keyboard or the thumbnails to move through the deck. Prefer to watch? See the recording.
Found the slides useful?Donations strengthen education, outreach, policy advocacy and the visibility of promising HSV research.
The programs we’re tracking
Eleven active programs across antivirals, vaccines and gene therapy, plus four that exited since Pipeline 4.0. Sorted from most to least advanced.
Pritelivir
AiCuris
Antiviral · HSV-1 and HSV-2 infection
April 2026. FDA granted Priority Review after the pivotal Phase 3 trial met its primary endpoint. Proposed indication: refractory HSV infection in immunocompromised patients. A decision is expected in Q4 2026.
Slide 24Adibelivir
Innovative Molecules
Antiviral · HSV-1 and HSV-2, including acyclovir-resistant strains
June 2026. The first patient was dosed in the Phase 2a proof-of-concept trial in recurrent genital herpes.
Slide 27BD111
Shanghai BDgene
Gene therapy · HSV-1 stromal keratitis
April 2025. Phase 2a began, testing BD111 with standard therapy against standard therapy alone.
Slide 11GS-1179
Gilead Sciences / Assembly Biosciences
Antiviral · HSV-2
August 2026. Gilead, which took control of the program in December 2025, selected GS-1179 for Phase 2. The trial is expected to start by the end of 2026.
Slide 26GS-5366
Gilead Sciences / Assembly Biosciences
Antiviral · HSV-2
May 2026. Gilead is advancing this long-acting antiviral toward Phase 2. Phase 1b showed reductions in viral shedding and genital lesion rates, with weekly and exploratory monthly dosing producing antiviral activity.
Slide 25BNT163
BioNTech
Prophylactic vaccine · HSV-2
October 2025. Interim data showed acceptable tolerability and binding and neutralizing antibodies against HSV-2. The trial is expected to finish in October 2026.
Slide 16Glycoprotein G-2 vaccine
Simplexia
Therapeutic and prophylactic vaccine · HSV-2
July 2026. Simplexia started SIMCT-001, an exploratory study to prepare for a planned Phase 1/2a program.
Slide 19Prime/Pull/Keep vaccine
University of California, Irvine (BenMohamed Lab)
Therapeutic vaccine · HSV-2 disease
June 2026. A five-year, $3.93 million NIH R01 award supports continued development.
Slide 20EBT-104
Excision BioTherapeutics
Gene therapy · HSV-1 keratitis
May 2025. In a rabbit model, CRISPR editing reduced latent HSV-1 and nearly eliminated ocular shedding.
Slide 12HSV gene-editing program
Fred Hutch Cancer Center (Jerome Lab)
Gene therapy · Latent HSV-1 and HSV-2
September 2024. The team published a gene-drive strategy: engineering HSV to carry genetic changes that can spread through viral populations, potentially disabling the virus’s ability to cause disease.
Slide 10SyB V-1901 (IV brincidofovir)
SymBio Pharma
Antiviral · HSV-1 replication
December 2025. SymBio obtained exclusive global rights from Tufts University to develop IV brincidofovir for Alzheimer’s disease and mild cognitive impairment, based on the HSV-1 research.
Slide 28GSK3943104
GSK
Therapeutic vaccine · HSV-2 disease
September 2024. The trial missed its primary efficacy endpoint, with no safety concerns. GSK ended development.
Slide 17mRNA-1608
Moderna
Therapeutic vaccine · HSV-2 disease
November 2025. Moderna ended the program in a portfolio-prioritization decision. It will not advance to Phase 3.
Slide 18RVX201
Rational Vaccines
Therapeutic vaccine · HSV-2 disease
July 2022. Rational Vaccines reported therapeutic efficacy against recurrent HSV-2 disease in a guinea pig model. Public evidence hasn’t shown enough recent progress since, so it no longer meets HCA’s preclinical criteria.
Slide 21Preclinical HSV-2 program
Shanghai BDgene
Gene therapy · Genital herpes (latent infection)
Listed for the past few years without program-specific development updates, so it no longer meets HCA’s preclinical criteria.
Slide 13How we chose these programs
Clinical development
Included: programs that are recruiting or active, enrolling or dosing participants, advancing through an officially announced trial, or moving through a regulatory process.
Excluded: completed studies awaiting financing, programs with no current clinical activity, discontinued development, and historical programs without active progression.
Selected preclinical research of interest
Included: programs with accessible and verifiable information, reasonably supportive results, recent evidence of continued activity, and a plausible path toward clinical development. HCA reviewed published literature and press releases.
Excluded: limited evidence of efficacy to treat or prevent herpes, undisclosed active matter, long-standing claims without advancement, or inaccessible or outdated information.
The pipeline is a current-state view, not an inventory of every historical HSV program, and the preclinical list is a selected view of work of interest, not a catalog of all HSV research.
Progress is real, but the pipeline is still too narrow
Gene editing, mRNA vaccines, tissue-targeted immunity and long-acting antivirals are expanding the HSV toolkit. But the pipeline still needs more approaches and early-stage programs. A broader pipeline creates more chances for durable control and, ultimately, a cure. Pipeline 5.0’s priorities:
- Sustain investment across prevention, treatment and cure, with an emphasis on broadening the pipeline
- Expand beyond the dominant antiviral targets and chemistries
- Advance preventive and therapeutic vaccines with differentiated strategies
- Develop effective, longer-acting and more convenient therapies that improve daily life
Presented by HCA’s board
Three members of Herpes Cure Advocacy’s board presented Pipeline 5.0 live on Zoom on October 7, 2026. Watch the full recording on YouTube.
HCA President
Jeffrey D. Klausner
MD, MPH
Clinical Professor of Medicine and Public Health, Keck School of Medicine of USC
HCA Secretary & Treasurer
Lao-Tzu Allan-Blitz
MD, MPH
Assistant Professor of Medicine, UCLA David Geffen School of Medicine
HCA Board Member at Large
Luis M. Schang
MV, PhD
Professor of Chemical Virology, Cornell University; past president, International Society for Antiviral Research
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The conference poster
Pipeline 5.0 debuted as a poster at the 2026 STI Prevention Conference in Atlanta. It summarizes the year’s changes in one page.
- Antivirals are advancing. Every antiviral drug in clinical development in Pipeline 4.0 has moved forward.
- Two vaccines were discontinued. Development stopped on two vaccine candidates that were in clinical development in Pipeline 4.0.
- A preclinical bottleneck. Little progress in the preclinical programs from Pipeline 4.0, and very few new approaches added or advanced.
Help build a broader pipeline
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