Assembly Biosciences Doses First Participant in Phase 1b Portion of Phase 1a/b Clinical Trial of Investigational Long-Acting Herpes Simplex Virus Helicase-Primase Inhibitor ABI-1179
Assembly Biosciences (Nasdaq: ASMB) has initiated the Phase 1b portion of its Phase 1a/b clinical trial for ABI-1179, a long-acting herpes simplex virus (HSV) helicase-primase inhibitor. The study will evaluate weekly oral doses over 29 days in participants with recurrent genital herpes, focusing on safety and antiviral activity.
The company reported that ABI-1179 demonstrated promising Phase 1a results, showing a pharmacokinetic profile supporting once-weekly oral dosing and low nanomolar potency against both HSV-1 and HSV-2 in vitro. Assembly Bio has received IND clearance to expand the study to U.S. sites.
Notably, Assembly Bio is conducting concurrent Phase 1b studies for both ABI-1179 and ABI-5366, with interim data expected in fall 2025. Under a collaboration agreement, Gilead Sciences maintains the right to opt in for an exclusive license for further development and commercialization of both candidates following review of the Phase 1b data package.
Assembly Biosciences (Nasdaq: ASMB) ha avviato la fase 1b della sua sperimentazione clinica di fase 1a/b per ABI-1179, un inibitore elicasi-primasi del virus herpes simplex (HSV) a lunga durata d'azione. Lo studio valuterà dosi orali settimanali per 29 giorni in partecipanti con herpes genitale ricorrente, concentrandosi sulla sicurezza e sull'attività antivirale.
L'azienda ha riportato che ABI-1179 ha mostrato risultati promettenti nella fase 1a, evidenziando un profilo farmacocinetico che supporta una somministrazione orale una volta a settimana e una potenza in nanomolare bassa contro HSV-1 e HSV-2 in vitro. Assembly Bio ha ottenuto l'autorizzazione IND per estendere lo studio a siti negli Stati Uniti.
Inoltre, Assembly Bio sta conducendo studi di fase 1b paralleli sia per ABI-1179 che per ABI-5366, con dati intermedi attesi nell'autunno 2025. In base a un accordo di collaborazione, Gilead Sciences mantiene il diritto di optare per una licenza esclusiva per lo sviluppo e la commercializzazione di entrambi i candidati dopo la revisione del pacchetto dati della fase 1b.
Assembly Biosciences (Nasdaq: ASMB) ha iniciado la fase 1b de su ensayo clínico fase 1a/b para ABI-1179, un inhibidor de la helicasa-primasa del virus herpes simplex (HSV) de acción prolongada. El estudio evaluará dosis orales semanales durante 29 días en participantes con herpes genital recurrente, enfocándose en la seguridad y la actividad antiviral.
La compañía informó que ABI-1179 mostró resultados prometedores en la fase 1a, presentando un perfil farmacocinético que respalda la dosificación oral semanal y una potencia en el rango nanomolar baja contra HSV-1 y HSV-2 in vitro. Assembly Bio ha recibido la aprobación IND para ampliar el estudio a sitios en EE. UU.
De manera destacada, Assembly Bio está llevando a cabo estudios concurrentes de fase 1b para ABI-1179 y ABI-5366, con datos intermedios esperados para el otoño de 2025. Bajo un acuerdo de colaboración, Gilead Sciences mantiene el derecho de optar por una licencia exclusiva para el desarrollo y comercialización de ambos candidatos tras revisar el paquete de datos de fase 1b.
Assembly Biosciences (나스닥: ASMB)는 장기 작용성 헤르페스 심플렉스 바이러스(HSV) 헬리케이스-프라이메이스 억제제인 ABI-1179의 1a/b상 임상시험 중 1b상 부분을 시작했습니다. 이 연구는 재발성 생식기 헤르페스 환자를 대상으로 29일 동안 주 1회 경구 투여 용량을 평가하며, 안전성과 항바이러스 활성을 중점적으로 살펴봅니다.
회사는 ABI-1179가 1a상에서 유망한 결과를 보였으며, 주 1회 경구 투여를 지원하는 약동학적 프로필과 HSV-1 및 HSV-2에 대해 낮은 나노몰 농도의 강력한 효능을 나타냈다고 보고했습니다. Assembly Bio는 미국 내 연구 확대를 위한 IND 승인을 받았습니다.
특히 Assembly Bio는 ABI-1179와 ABI-5366 두 후보물질에 대해 동시에 1b상 연구를 진행 중이며, 중간 데이터는 2025년 가을에 발표될 예정입니다. 협력 계약에 따라 Gilead Sciences는 1b상 데이터 패키지 검토 후 두 후보물질의 추가 개발 및 상용화를 위한 독점 라이선스 선택권을 보유합니다.
Assembly Biosciences (Nasdaq : ASMB) a lancé la phase 1b de son essai clinique de phase 1a/b pour ABI-1179, un inhibiteur hélicase-primase du virus herpès simplex (HSV) à action prolongée. L'étude évaluera des doses orales hebdomadaires sur 29 jours chez des participants atteints d'herpès génital récurrent, en se concentrant sur la sécurité et l'activité antivirale.
La société a rapporté que ABI-1179 avait montré des résultats prometteurs en phase 1a, présentant un profil pharmacocinétique soutenant une administration orale hebdomadaire et une puissance en nanomolaire faible contre HSV-1 et HSV-2 in vitro. Assembly Bio a obtenu l'autorisation IND pour étendre l'étude à des sites aux États-Unis.
Notamment, Assembly Bio mène simultanément des études de phase 1b pour ABI-1179 et ABI-5366, avec des données intermédiaires attendues à l'automne 2025. Dans le cadre d'un accord de collaboration, Gilead Sciences conserve le droit d'opter pour une licence exclusive pour le développement et la commercialisation ultérieurs des deux candidats après examen du dossier de données de la phase 1b.
Assembly Biosciences (Nasdaq: ASMB) hat den Phase-1b-Teil seiner Phase-1a/b-Studie für ABI-1179 gestartet, einen langwirksamen Helikase-Primase-Inhibitor gegen das Herpes-simplex-Virus (HSV). Die Studie wird wöchentliche orale Dosen über 29 Tage bei Teilnehmern mit rezidivierendem Genitalherpes untersuchen, wobei der Fokus auf Sicherheit und antiviraler Aktivität liegt.
Das Unternehmen berichtete, dass ABI-1179 vielversprechende Phase-1a-Ergebnisse zeigte, mit einem pharmakokinetischen Profil, das eine einmal wöchentliche orale Dosierung unterstützt, sowie einer niedrigen nanomolaren Wirksamkeit gegen HSV-1 und HSV-2 in vitro. Assembly Bio hat die IND-Freigabe erhalten, um die Studie auf Standorte in den USA auszuweiten.
Bemerkenswert ist, dass Assembly Bio gleichzeitig Phase-1b-Studien für ABI-1179 und ABI-5366 durchführt, wobei Zwischenberichte für Herbst 2025 erwartet werden. Im Rahmen einer Kooperationsvereinbarung behält sich Gilead Sciences das Recht vor, nach Prüfung des Phase-1b-Datenpakets eine exklusive Lizenz für die weitere Entwicklung und Vermarktung beider Kandidaten zu erwerben.
- Successful advancement to Phase 1b following positive Phase 1a results
- ABI-1179 demonstrated pharmacokinetic profile supporting convenient once-weekly oral dosing
- Low nanomolar potency shown against both HSV-1 and HSV-2 in vitro
- IND clearance received for U.S. site expansion
- Partnership with Gilead Sciences provides potential commercialization pathway
- Phase 1b efficacy and safety data still pending
- Gilead's opt-in decision remains uncertain
- Competitive therapy landscape in herpes treatment market
Insights
Assembly Bio advances HSV drug ABI-1179 to Phase 1b testing with potential Gilead partnership pending results in fall 2025.
Assembly Biosciences has initiated the Phase 1b portion of its clinical trial for ABI-1179, a long-acting herpes simplex virus (HSV) helicase-primase inhibitor. This represents a significant milestone in their infectious disease pipeline development. The company is now evaluating weekly oral doses in participants with recurrent genital herpes, following positive Phase 1a results that supported once-weekly dosing potential.
The study design is particularly notable for its comprehensive endpoints. Researchers will track both viral parameters (HSV-2 shedding rates and DNA levels) and clinical outcomes (days with lesions) over a 29-day treatment period. This dual-measurement approach will provide a more complete picture of efficacy beyond just safety data typically emphasized in early trials.
What's strategically important is that Assembly Bio is simultaneously advancing two complementary HSV candidates - ABI-1179 and ABI-5366 - with parallel Phase 1b trials using equivalent criteria and overlapping research sites. To maintain enrollment timelines while running concurrent studies, the company secured an IND clearance for US site expansion.
The collaboration agreement with Gilead Sciences adds significant value potential. Gilead retains exclusive license opt-in rights for both candidates after reviewing the Phase 1b data packages. With interim results for both compounds expected in fall 2025, this represents a near-term catalyst that could materially impact Assembly Bio's pipeline valuation and partnership prospects.
– Study will evaluate safety and antiviral activity of ABI-1179 in participants with recurrent genital herpes –
– ABI-1179 IND cleared to support study expansion to sites in United States –
– Phase 1b studies for ABI-1179 and ABI-5366 running concurrently with interim data for both candidates on track for fall 2025 –
SOUTH SAN FRANCISCO, Calif., June 30, 2025 (GLOBE NEWSWIRE) -- Assembly Biosciences, Inc. (Nasdaq: ASMB), a biotechnology company developing innovative therapeutics targeting serious viral diseases, today announced that the first participant has been dosed in the Phase 1b portion of the Phase 1a/b study of its long-acting herpes simplex virus (HSV) helicase-primase inhibitor candidate ABI-1179.
The Phase 1b study will evaluate the safety and antiviral activity of weekly oral doses of ABI-1179 over a 29-day treatment period in participants with recurrent genital herpes. Antiviral activity will be evaluated by assessing changes in viral parameters, including HSV type 2 (HSV-2) shedding rate and levels of HSV-2 DNA. Effects on clinical parameters including days with lesions will also be measured. ABI-1179 demonstrated positive interim Phase 1a results with a pharmacokinetic (PK) profile supporting once-weekly oral dosing in healthy participants and has exhibited low nanomolar potency against both HSV type 1 (HSV-1) and HSV-2 in vitro.
Assembly Bio has advanced both ABI-5366 and ABI-1179 into Phase 1b studies after each long-acting helicase-primase inhibitor candidate exceeded the company’s target PK profiles in Phase 1a evaluation in healthy participants. The Phase 1b studies utilize equivalent eligibility criteria and outcome measures and are being conducted at overlapping sites. To maintain enrollment timelines while running both trials concurrently, Assembly Bio has received clearance for an Investigational New Drug application (IND) for ABI-1179 to support expansion of this Phase 1b study to sites in the United States. The studies for both candidates are on track to report interim data in fall 2025.
“For the millions of individuals affected by recurrent genital herpes, current therapies fall short in managing the significant impact repeated outbreaks have on their lives,” said Anuj Gaggar, MD, PhD, chief medical officer of Assembly Bio. “With the Phase 1b study of ABI-1179 now underway, we look forward to evaluating viral and clinical outcomes for both promising long-acting HSV investigational therapies, ABI-5366 and ABI-1179, and we remain on track for interim data from both studies in the fall of this year.”
Under the collaboration agreement between Assembly Bio and Gilead Sciences, Inc. (Gilead), Gilead has the right to opt in to an exclusive license for further development and commercialization of ABI-1179 and ABI-5366 after reviewing the Phase 1b data package to be delivered by Assembly Bio following completion of the studies.
About ABI-1179-101
ABI-1179-101 is a randomized, blinded, placebo-controlled Phase 1a/b clinical study of ABI-1179. Interim data has been reported for Part A (Phase 1a), evaluating the safety, tolerability and PK of ABI-1179 following single dose administration in healthy participants randomized 6:2 between ABI-1179 and placebo in up to five cohorts at different dose levels. Dosing has also initiated for Part B (Phase 1b) in participants seropositive for HSV-2 with recurrent genital herpes, which will evaluate weekly oral doses over a 29-day dosing period. Participants in Part B will be randomized 20:5 between ABI-1179 and placebo in up to four cohorts, exploring different dose levels with a pooled placebo analysis.
In addition to assessing safety, tolerability and PK, Part B will also evaluate antiviral activity by measuring changes in the viral parameters including viral shedding rate and HSV-2 DNA levels obtained from anogenital swab samples, and clinical parameters including lesion recurrence rate and lesion duration. The trial results will support dose selection for future clinical trials.
Additional information about the Phase 1a/b trial is available at clinicaltrials.gov using the identifier NCT06698575. Assembly Bio expects to submit data from the trial for presentation at future scientific meetings.
ABI-1179 was contributed by Gilead under the collaboration between Assembly Bio and Gilead. ABI-1179 and ABI-5366 are investigational product candidates that have not been approved anywhere globally, and their safety and efficacy have not been established.
About Recurrent Genital Herpes
Genital herpes is a chronic viral infection caused by the herpes simplex virus (HSV) that can result in painful genital lesions, serious psychological and social impacts, and an increased risk of acquiring human immunodeficiency virus (HIV). Epidemiologic studies estimate over four million people in the United States and France, Germany, Italy, Spain and the United Kingdom experience recurrent genital herpes, with most people with initial symptomatic genital HSV type 2 (HSV-2) infection having three or more recurrences per year. While genital herpes can be caused by either HSV type 1 (HSV-1) or HSV-2, recurrences are more likely to be experienced by individuals infected by HSV-2. The current standard of care for recurrent genital herpes is nucleoside analogs given intermittently for recurrences or as daily chronic suppressive therapy; however, these are only partially effective in preventing recurrences and in reducing transmission of the virus. No new drugs have been approved in the United States or Europe to treat genital herpes for more than 25 years.
About Helicase-Primase Inhibition
HSV helicase-primase inhibitors target the viral helicase-primase complex, an essential viral enzyme complex that is conserved across both HSV-1 and HSV-2 and has no host equivalent. Inhibition of the helicase-primase complex is a clinically validated mechanism that has shown the potential for superior efficacy to the current standard of care, nucleoside analogs, in short-duration clinical studies in participants with recurrent genital herpes.
About Assembly Biosciences
Assembly Biosciences is a biotechnology company dedicated to the development of innovative small-molecule therapeutics designed to change the path of serious viral diseases and improve the lives of patients worldwide. Led by an accomplished team of leaders in virologic drug development, Assembly Bio is committed to improving outcomes for patients struggling with the serious, chronic impacts of herpesvirus, hepatitis B virus (HBV) and hepatitis delta virus (HDV) infections. For more information, visit assemblybio.com.
Forward-Looking Statements
The information in this press release contains forward-looking statements that are subject to certain risks and uncertainties that could cause actual results to materially differ. These risks and uncertainties include: Assembly Bio’s ability to maintain financial resources necessary to continue its research activities, clinical studies and other business operations; Assembly Bio’s ability to realize the potential benefits of its collaboration with Gilead Sciences, Inc. (Gilead), including all financial aspects of the collaboration and equity investments; Assembly Bio’s ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio’s collaboration with Gilead, in the currently anticipated timeframes or at all; safety and efficacy data from clinical or nonclinical studies may not warrant further development of Assembly Bio’s product candidates; clinical and nonclinical data may not differentiate Assembly Bio’s product candidates from other companies’ candidates; potential effects of changes in government regulation, including as a result of the change in U.S. administration in 2025; results of nonclinical studies may not be representative of disease behavior in a clinical setting and may not be predictive of the outcomes of clinical studies; and other risks identified from time to time in Assembly Bio’s reports filed with the U.S. Securities and Exchange Commission (the SEC). You are urged to consider statements that include the words may, will, would, could, should, might, believes, hopes, estimates, projects, potential, expects, plans, anticipates, intends, continues, forecast, designed, goal or the negative of those words or other comparable words to be uncertain and forward-looking. Assembly Bio intends such forward-looking statements to be covered by the safe harbor provisions contained in Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. More information about Assembly Bio’s risks and uncertainties are more fully detailed under the heading “Risk Factors” in Assembly Bio’s filings with the SEC, including its most recent Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K. Except as required by law, Assembly Bio assumes no obligation to update publicly any forward-looking statements, whether as a result of new information, future events or otherwise.
Contacts
Investor and Corporate:
Shannon Ryan
SVP, Investor Relations, Corporate Affairs and Alliance Management
(415) 738-2992
investor_relations@assemblybio.com
Media:
Sam Brown Inc.
Hannah Hurdle
(805) 338-4752
ASMBMedia@sambrown.com
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