Teleconferência de Resultados do 3T de 2026 da Vir Biotechnology (VIR): Dados do ECLIPSE e Acordo com a Gilead

A Vir Biotechnology (NASDAQ: VIR) encerrou o terceiro trimestre de 2026 com US$ 901 milhões em caixa, equivalentes de caixa e investimentos, enquanto avançava com três estudos de Fase III para hepatite delta e expandia suas parcerias em oncologia. A empresa espera a divulgação dos principais dados do programa ECLIPSE até o primeiro trimestre de 2027 e projeta que sua autonomia de caixa se estenderá até o segundo semestre de 2028.

Principais destaques

• A Vir encerrou o terceiro trimestre de 2026 com US$ 901 milhões em caixa, equivalentes de caixa e investimentos. Esse valor não inclui os US$ 90 milhões recebidos da Gilead em outubro.
• A administração espera os dados preliminares (topline) da Fase III do ECLIPSE-1 no quarto trimestre de 2026, seguidos pelos resultados do ECLIPSE-2 e do ECLIPSE-3 no primeiro trimestre de 2027.
• As despesas com P&D no terceiro trimestre caíram para US$ 80 milhões, ante US$ 151 milhões no mesmo período do ano anterior, principalmente porque o terceiro trimestre de 2025 incluiu um pagamento único de marco (milestone) de US$ 75 milhões referente ao VIR-5525.
• O VIR-5500 atingiu prova de conceito com base em dados clínicos, de segurança, farmacológicos e de biomarcadores. O FDA também concedeu a designação Fast Track para câncer de próstata metastático resistente à castração em linhas avançadas de tratamento.
• A colaboração com a Gilead gerou US$ 65 milhões em pagamento inicial (upfront) e um investimento em participação acionária de US$ 25 milhões com ágio de 30%. A Vir é elegível para receber até US$ 45 milhões em marcos pré-clínicos de curto prazo e até US$ 1,74 bilhão em marcos adicionais.
• Com base em seu plano operacional atual, a administração projeta que o caixa disponível financiará as operações até o segundo semestre de 2028.

Principais dados financeiros

Desempenho operacional e dos negócios

Programa de Fase III para hepatite delta

O programa de Fase III ECLIPSE da Vir está avaliando a combinação subcutânea mensal de elebsiran e tobevibart em pacientes virgens de tratamento, pacientes em transição a partir do bulevirtide e em uma comparação direta (head-to-head) com o bulevirtide.

O ECLIPSE-1 incluiu cerca de 120 participantes virgens de tratamento randomizados na proporção de 2:1 entre o regime combinado e o tratamento postergado. Seu desfecho primário é o RNA do HDV indetectável (TND, ou target not detected), combinado com a normalização da ALT na semana 48.

O ECLIPSE-2 incluiu cerca de 150 pacientes com resposta inadequada ao bulevirtide. Os participantes foram randomizados na proporção de 2:1, e o desfecho primário é o RNA do HDV indetectável (TND) na semana 24.

O ECLIPSE-3 incluiu cerca de 100 pacientes virgens de tratamento randomizados na proporção de 2:1 entre a combinação da Vir e o bulevirtide. Seu desfecho primário é o RNA do HDV indetectável (TND) na semana 48.

A administração afirmou que os dados do estudo de Fase II SOLSTICE demonstraram TND em cerca de 66% dos pacientes após 48 semanas. A empresa acredita que a atividade antiviral do regime e a administração mensal poderiam diferenciá-lo do tratamento diário com bulevirtide.

Programa de câncer de próstata com o VIR-5500

O VIR-5500, um engajador de células T direcionado ao PSMA duplamente mascarado (dual-masked) e codesenvolvido com a Astellas, alcançou prova de conceito com base na totalidade dos dados de eficácia, segurança, farmacologia e biomarcadores obtidos até o momento.

O FDA concedeu ao VIR-5500 a designação Fast Track para câncer de próstata metastático resistente à castração em linhas avançadas de tratamento. Um estudo de Fase I está avaliando monoterapia e terapia combinada em seis coortes de expansão de dose, incluindo mCRPC virgem de taxanos, virgem de terapia com radioligantes e exposto à terapia com radioligantes, além de câncer de próstata metastático sensível a hormônios.

A Vir e a Astellas pretendem iniciar múltiplos estudos de Fase III em linhas iniciais e avançadas durante 2027. As empresas também estão trabalhando na preparação da capacidade de fabricação.

Outros programas de oncologia

O VIR-5818, engajador de células T direcionado ao HER2 da Vir, permanece em desenvolvimento na Fase I como monoterapia e em combinação com pembrolizumabe. Após feedback do FDA, a Vir planeja adicionar coortes de preenchimento (backfill) em monoterapia em uma população de pacientes mais homogênea para refinar a seleção de dose e esquema posológico. Portanto, o conjunto de dados ainda não está completo, e a empresa não planeja mais fornecer a atualização anteriormente prevista para 2026.

O VIR-5525, um engajador de células T direcionado ao EGFR, segue em escalonamento de dose como monoterapia e em combinação com pembrolizumabe em cânceres de pulmão, colorretal, carcinoma espinocelular de cabeça e pescoço e carcinoma espinocelular cutâneo.

Colaboração com a Gilead

Nos termos da colaboração de pesquisa multiprograma, a Vir descobrirá, projetará e otimizará três candidatos a desenvolvimento de engajadores de células T mascarados com a tecnologia PRO-XTEN para alvos em tumores sólidos. A Gilead deterá direitos exclusivos para avançar com os candidatos e gerenciará o desenvolvimento posterior, a fabricação e a comercialização.

Além da contraprestação inicial de US$ 90 milhões, a Vir é elegível para receber até US$ 45 milhões em marcos pré-clínicos de curto prazo e até US$ 1,74 bilhão em marcos adicionais de desenvolvimento, regulatórios e comerciais. O acordo também inclui royalties escalonados que variam de dígitos simples altos a dígitos duplos baixos.

A Vir informou que o repasse econômico anterior de 20% para a Sanofi havia expirado antes do acordo, o que significa que os pagamentos de marcos da colaboração não serão compartilhados com a Sanofi.

Projeções da administração (Guidance)

• Os resultados preliminares (topline) do ECLIPSE-1 são esperados para o quarto trimestre de 2026.
• Os resultados preliminares (topline) do ECLIPSE-2 e do ECLIPSE-3 são esperados para o primeiro trimestre de 2027.
• A Vir planeja fornecer uma atualização mais ampla sobre sua estratégia de imuno-oncologia em um evento virtual de pesquisa para investidores no primeiro trimestre de 2027.
• A Vir e a Astellas têm como objetivo iniciar múltiplos estudos de Fase III do VIR-5500 durante 2027, sujeitos ao planejamento regulatório em andamento.
• A administração projeta que o caixa financiará as operações até o segundo semestre de 2028, de acordo com o plano operacional atual.

Riscos e pontos de atenção

Os desfechos regulatórios do programa ECLIPSE continuam dependentes dos dados pendentes da Fase III. O ECLIPSE-1 precisa avaliar um desfecho composto de TND e normalização da ALT, enquanto o ECLIPSE-2 e o ECLIPSE-3 utilizam desfechos primários apenas de TND em diferentes momentos.

Em relação ao VIR-5818, o feedback do FDA levou a Vir a refinar o estudo de monoterapia e adicionar coortes de preenchimento (backfill). A administração afirmou que o conjunto de dados continua incompleto e não forneceu um novo cronograma para uma atualização clínica.

A Vir não divulgou dados atualizados sobre a durabilidade da resposta do VIR-5500 nem critérios detalhados de prova de conceito. Informações clínicas adicionais poderão ser apresentadas antes do início dos estudos pivotais.

Destaques da sessão de perguntas e respostas dos analistas

• Divulgação do ECLIPSE-1: A administração espera divulgar o desfecho primário composto, desfechos secundários relevantes, informações sobre o subgrupo com cirrose e dados de segurança e tolerabilidade.
• Limiar competitivo do ECLIPSE-3: A administração citou taxas de TND com bulevirtide de aproximadamente 12% a 20% após 48 semanas e as comparou com cerca de 66% no estudo de Fase II SOLSTICE, mas não especificou a diferença mínima necessária para o sucesso clínico ou comercial.
• Preparação para a comercialização no HDV: A Vir realizou pesquisas de mercado com profissionais de saúde e fontes pagadoras, avaliou tendências diagnósticas e analisou canais de distribuição para administração domiciliar e por profissionais de saúde.
• Oportunidade de transição a partir do bulevirtide: A administração destacou o rápido recrutamento no ECLIPSE-2 como um indicador de demanda entre pacientes inadequadamente controlados com bulevirtide. O estudo também está gerando dados de transição relevantes para as preocupações com exacerbações (flares).
• Desenvolvimento pivotal do VIR-5500: A Vir planeja atuar tanto em linhas iniciais quanto avançadas de câncer de próstata, mas fornecerá detalhes específicos dos desenhos de Fase III em conjunto com a Astellas em uma data posterior.

Transcrição completa da teleconferência de resultados

Transcrição completa da teleconferência de resultados

Comentários da administração

Operator

Hello, and welcome to Vir Biotechnology's Third Quarter 2026 Financial Results and Corporate Update Conference Call. As a reminder, this call is being recorded.

[Operator Instructions] I will now turn the call over to Kiki Patel, Head of Investor Relations. You may begin, Kiki.

Kiki Patel

Thank you, operator, and welcome, everyone. Earlier today, we issued a press release reporting our third quarter 2026 financial results and corporate update.

Before we begin, I'd like to remind everyone that some of the statements we are making today are forward-looking statements under applicable securities laws. Forward-looking statements include, but are not limited to, statements regarding the therapeutic and commercial potential of our clinical and preclinical programs, our development plans and time lines, our collaborations with other companies, our cash runway and capital allocation priorities and as otherwise described in the legal disclaimers accompanying our public presentations. These forward-looking statements involve substantial risks and uncertainties, which are described in our reports filed with the Securities and Exchange Commission, including our Forms 10-K, 10-Q, and 8-K, and could cause future results, performance or achievements to differ significantly from those expressed or implied by such forward-looking statements.

Joining me on today's call from Vir Biotechnology are Dr. Marianne De Backer, our President and Chief Executive Officer; and Aziz Sawaf, our Chief Financial Officer.

The agenda for our call today is as follows: First, Marianne will provide a strategic update on where Vir Bio stands today, including an overview of our Phase III registrational program in hepatitis delta. Next, she will review the latest updates across the PRO-XTEN dual mass T-cell engager program and present the highlights of our recently announced preclinical collaboration with Gilead. Next, Aziz will review the financial terms of our recent collaboration with Gilead and provide a summary of our third quarter 2026 financial results. And finally, Marianne will close the call, and we'll open the line for Q&A.

With that, I'll now turn the call over to Marianne.

Marianne De Backer

Thank you, Kiki. Good afternoon, everyone, and thank you for joining us for Vir Biotechnology's Third Quarter 2026 Financial Results Conference Call. We are entering a pivotal period for Vir Bio with the potential to transform hepatitis delta treatment while building a differentiated oncology franchise.

Today, I will highlight significant progress across both those areas and why we believe Vir Bio is well positioned for meaningful value creation ahead. First, we've expanded our leadership team with the addition of Aziz Sawaf as Chief Financial Officer; and Dr. David Liu as Chief Medical Officer. Both bring more than 20 years of experience in their respective fields, further bolstering our capabilities as we enter an important period for Vir Bio. With our leadership team strengthened, we are well positioned to execute against the significant opportunities and catalysts ahead.

Second, our hepatitis delta program continues to advance through Phase III development. We expect to report top line data from ECLIPSE-1 this quarter, followed by top line data from ECLIPSE-2 and ECLIPSE-3 in the first quarter of 2027. We will also present expanded 96-week Phase II SOLSTICE results in an oral presentation at AASLD this weekend.

Third, we have made meaningful progress across our oncology portfolio. Astellas recently announced that VIR-5500 achieved proof of concept, reinforcing the scientific rationale for advancing the program into late-stage development. In addition, we are pleased to share that the FDA granted Fast Track designation to VIR-5500 for the treatment of late-line metastatic castration-resistant prostate cancer.

And finally, our recent research collaboration with Gilead underscores the potential of our PRO-XTEN platform and highlights the strength of our integrated AI-enabled capabilities in T-cell engager discovery and optimization. This collaboration represents the second major external validation of the PRO-XTEN masking technology in the last 8 months, following our partnership with Astellas on VIR-5500 in February. Overall, these achievements position us well to execute on our strategic priorities and deliver against the important catalysts ahead.

Now starting with our hepatitis delta program. Chronic hepatitis delta remains one of the most severe and underserved forms of viral liver disease. October was Liver Cancer Awareness Month and the World Hepatitis Alliance has focused on amplifying the message that hepatitis elimination is liver cancer prevention. Hepatitis delta is associated with a two- to six-fold higher risk of liver cancer compared to hepatitis B alone and was classified as carcinogenic by the World Health Organization's International Agency for Research on Cancer last year.

While recent advances have expanded treatment options for patients, there remains a critical need for therapies capable of delivering deeper antiviral activity and more complete disease control. Current approaches have generally focused on decreasing the viral load, but many patients continue to have detectable HDV RNA despite treatment. Hepatologists and treating physicians believe that achieving complete viral elimination to where the virus is undetectable, defined by HDV RNA target not detected or TND, represents an important next frontier in hepatitis delta care, representing deeper disease control and potential clinical benefit for patients.

Building on the encouraging TND results observed in our Phase II SOLSTICE trial, the ECLIPSE program is designed to determine whether this approach can consistently deliver profound viral suppression across key populations. ECLIPSE-1 is designed to provide the first Phase III assessment of the proportion of patients who can achieve undetectable HDV RNA after 48 weeks of treatment with our combination regimen of elebsiran and tobevibart. The trial has enrolled approximately 120 participants randomized 2:1 to monthly subcutaneous dosing of our combination regimen versus deferred treatment in treatment-naive patients with chronic hepatitis delta. The primary endpoint is a composite of HDV RNA TND together with ALT normalization at week 48.

ECLIPSE-2 has enrolled approximately 150 patients who are being randomized 2:1, evaluating the switch to our combination therapy in patients who have an inadequate response to bulevirtide. The primary endpoint for the trial is undetectable virus as defined by HDV RNA TND at week 24. The pace of enrollment we observed in Europe for this trial reflects an important unmet need in patients previously treated with bulevirtide.

ECLIPSE-3 is our pivotal head-to-head trial against bulevirtide in treatment-naive patients. We have enrolled approximately 100 patients randomized 2:1 to our combination therapy versus bulevirtide. The primary endpoint for the trial is undetectable virus as defined by HDV RNA TND at week 48. Together, ECLIPSE-1, ECLIPSE-2 and ECLIPSE-3 are expected to provide a comprehensive data package, generating data in treatment-naive patients, patients switching from bulevirtide and patients enrolled in a head-to-head comparison against bulevirtide.

As bulevirtide utilization grows, physicians will need evidence-based guidance on how best to manage patients who do not achieve adequate file suppression or who require an alternative treatment approach. To our knowledge, no other late-stage HDV development program is expected to include comparable bulevirtide switch or head-to-head data in its regulatory submission package, potentially providing a uniquely comprehensive evidence base for physicians, payers and regulators. Collectively, these studies are designed to position our program at the very forefront of the evolving hepatitis delta treatment landscape and ultimately improve outcomes for patients living with this devastating disease.

Turning now to oncology. VIR-5500 is our PRO-XTEN dual-masked PSMA-targeted T-cell engager, which we are advancing in a global co-development and co-commercialization collaboration with Astellas for prostate cancer. Astellas already shared on its earnings call yesterday that VIR-5500 has achieved proof of concept, reinforcing the scientific rationale for advancing the program into registrational trials. This assessment reflects the totality of the clinical, safety, pharmacology and biomarker data generated to-date and supports continued investment in the registrational planning and execution.

We also recently announced that the FDA granted Fast Track designation to VIR-5500 for the treatment of late-line metastatic castration-resistant prostate cancer, or mCRPC, underscoring VIR-5500's potential to address a significant unmet need in patients who have limited treatment options. Both of these milestones highlight the strong progress we have made with our partner, Astellas, as we advance the program towards pivotal trials.

VIR-5500 is currently being evaluated in a Phase I trial as both a monotherapy and combination therapy across 6 dose expansion cohorts. Indications include Taxane-naive mCRPC, radioligand therapy-naive mCRPC, radioligand therapy exposed mCRPC, and metastatic hormone-sensitive prostate cancer. These expansion studies are designed to inform the next phase of development with the goal of initiating multiple Phase III studies spanning both early-line and late-line settings in 2027.

In parallel, we are focused on advancing manufacturing readiness in collaboration with Astellas. Importantly, our plans to pursue first-line mCRPC reflect our belief that VIR-5500 has the potential to become a foundational therapy across the prostate cancer treatment continuum.

Moving now to VIR-5818, our HER2-targeted T-cell engager. This program is currently being evaluated in a Phase I trial with dose escalation and signal finding components, both as monotherapy and in combination with pembrolizumab. The trial has enrolled patients with a variety of HER2-expressing cancers.

During our last update on the program, we shared encouraging antitumor activity and a generally well-tolerated safety profile. While we had previously anticipated providing a data update on the program this year, recent FDA feedback on the monotherapy arm has led us to refine the study. We intend to add backfill cohorts in a more homogeneous patient population to help determine the optimal dose and schedule, which is aligned with FDA's Project Optimus, an initiative to reform the dose optimization and dose selection paradigm in oncology drug development.

As a result, the study remains ongoing and the data set is not yet complete. In parallel, dose escalation and optimization of VIR-5818 in combination with pembrolizumab is ongoing. We anticipate presenting a meaningful update on VIR-5818 at a future scientific conference. Finally, VIR-5525, our EGFR-targeted T-cell engager continues to progress through dose escalation in both monotherapy and combination therapy with pembrolizumab across lung cancer, colorectal cancer, head and neck squamous cell carcinoma, and cutaneous squamous cell carcinoma.

Looking ahead, our preclinical immuno-oncology pipeline is fueling a growing oncology portfolio. We are in a fortunate position where the breadth of opportunities generated by our scientific platform exceeds what we can advance independently, allowing us to be strategic about which programs we progress ourselves. In the first quarter of 2027, we plan to provide a more comprehensive view of the next chapter of our cancer immunotherapy strategy at a virtual research investor event.

We will provide investors with a road map for how we plan to build and scale a world-class immuno-oncology franchise. The breadth of our pipeline does not mean we will advance every opportunity ourselves. We intend to be disciplined in how we allocate capital, concentrating investment where our capabilities are most differentiated and partnering strategically where collaboration can accelerate development, expand reach and maximize the impact of our platform for patients.

Our research collaboration with Gilead is an example of this strategy in action, providing further external validation of the PRO-XTEN platform and the potential to deliver T-cell engagers with an improved safety profile. This preclinical multi-program collaboration leverages Vir Bio's integrated expertise in T-cell engager discovery and protein engineering. Our proprietary dAIsY platform for rapid multiparameter optimization of high-quality T-cell engagers and the PRO-XTEN masking technology to develop next-generation T-cell engagers across multiple solid tumor targets.

Under the agreement with Gilead, Vir Bio will be responsible for the discovery, design and optimization of 3 PRO-XTEN Mas T-cell engager development candidates with the potential to address multiple solid tumor indications with significant unmet medical need. Gilead will have the exclusive rights to advance candidates generated through the collaboration and will be responsible for subsequent development, manufacturing, and commercialization.

With that, I'll now hand the call over to Aziz, who will walk through the financial terms of our Gilead collaboration and our third quarter financial results.

Aziz Sawaf

Thanks, Marianne. Before I begin, I'd like to say how pleased I am to have joined Vir Bio at this exciting time for the company. I look forward to working with the team to build on the company's progress and help translate the strength of the portfolio into long-term value for shareholders and patients. The Gilead collaboration is a strong example of that opportunity.

As Marianne discussed, the agreement provides further validation of our oncology platform while increasing our financial flexibility. It also demonstrates how selective partnerships can preserve meaningful long-term value and support disciplined capital allocation. Under the agreement, we received $90 million, consisting of $65 million upfront and a $25 million equity investment at a 30% premium. We are also eligible to receive up to $45 million in near-term preclinical milestones.

Beyond that, we have the potential to receive up to $1.74 billion in additional development, regulatory and commercial milestones, along with tiered high single to low double-digit royalties. Importantly, the 20% pass-through economics to Sanofi has expired and were no longer in effect at the time of the agreement. As a result, none of the milestone payments from this collaboration will be shared with Sanofi.

Turning to our Q3 financial results, where I'll focus on a few key metrics. R&D expense was $80 million compared with $151 million for the same period in 2025. The reduction was primarily driven by a onetime $75 million milestone payment recognized in the third quarter of 2025, following the first patient dosed with VIR-5525. SG&A expense was $24 million compared with $22 million for the same period in 2025. The increase was primarily due to higher advisory and legal fees. We ended the quarter with $901 million in cash, cash equivalents and investments.

Importantly, this balance does not include the $90 million upfront from the Gilead collaboration, which was received in October. Based on our current operating plan, we project that our cash will fund operations into the second half of 2028.

As we look ahead, we will remain thoughtful and disciplined in how we deploy capital. Our focus will be on supporting the company's highest priority programs, preserving financial flexibility around important inflection points and ensuring that our investments remain aligned with the potential to create long-term value for shareholders and patients.

With that, I'll turn the call back to Marianne, to conclude. Marianne?

Marianne De Backer

Thank you, Aziz. In summary, I'm incredibly proud of the strong execution we have delivered in the third quarter of this year. In hepatitis delta, the totality of evidence generated from our SOLSTICE program continues to reinforce our confidence in the potential of elebsiran and tobevibart to offer a highly differentiated treatment profile. Combined with once-monthly subcutaneous administration and the potential for both at-home or health care provider administration, we believe our regimen could become a best-in-class treatment option capable of redefining expectations for patients. We look forward to sharing the top line results of our Phase III ECLIPSE-1 trial later this quarter and ECLIPSE-2 and ECLIPSE-3 trials in the first quarter of next year.

In oncology, VIR-5500 continues to advance rapidly. Following the Fast Track designation granted last month and with expansion cohorts actively enrolling, we and Astellas look forward to sharing more on our registrational development plans next year. Furthermore, the collaboration we announced with Gilead further validates our integrated drug discovery capabilities and demonstrates our ability to create value through strategic partnerships that both extend the reach of our technology and help support investment in our wholly-owned oncology portfolio. Taken together, these developments reinforce our confidence in the breadth of the platform and help further define the path forward for the program.

I'm excited about what we have built and the opportunity ahead. We have the potential to redefine the treatment paradigm in hepatitis delta, advance a new treatment approach in prostate cancer and bring other important new therapies to patients. And finally, we are entering this next phase from a position of financial strength, well capitalized and poised for what we believe will be a transformative period in our company's history.

With that, I'll turn the call over to Kiki, to begin the Q&A session.

Kiki Patel

Thank you, Marianne. This concludes our prepared remarks, and we will now start the Q&A session. Joining me for the Q&A are Marianne and Aziz. Please limit questions to 2 per person so we can get to all of our covering analysts.

I'll turn it over to you, operator.

Operator

[Operator Instructions] Your first question comes from the line of Cory Kasimov with Evercore ICI.

Perguntas e respostas

Unknown Analyst

It's Johnny on for Cory. Regarding VIR-5500, if you could tell us about the durability of responses that you're seeing already in the current trial.

Marianne De Backer

Sorry, I did not get your name.

Unknown Analyst

Sorry, it's Johnny on for Cory.

Marianne De Backer

Okay. Great. Yes. Thank you for that question. So we are not sharing any updated information on VIR-5500 at this time. But as you have seen, we have made some really remarkable progress, the Fast Track designation by the FDA for late time and CRPC patients. And then Astellas yesterday already shared in their earnings call that we have designated the program as having achieved proof of concept. So that is a very important hurdle to prepare for our pivotal trials next year. And so in the course of next year, prior to our pivotal trials, we will be in a position to potentially share more.

Operator

Your next question comes from the line of Mike Oz with Morgan Stanley.

Avraham Novick

It's Avi Novak on the line for Mike. Congrats on all the progress. I guess as I'm sure you've seen a competitor recently shared their Phase III HDV data. So I was wondering, I guess, your thoughts -- updated thoughts on competitive positioning. Does this change the competitive bar in your view for your Phase III trial, acknowledging that there is, of course, a difference in your endpoints and how you're defining a responder.

Marianne De Backer

Yes. Thank you for that question, Avi. So as you recall, in our Phase II SOLSTICE data, we have shown to be in a possibility to achieve 60%, 60% of target not detected. So really getting rid of the virus in 66% of the patients after 48 weeks of treatment. And what you have seen from the competition, I think, for the 24-week endpoint is, I believe, a 17% target not detected. So we still believe that from an efficacy perspective and everything we have shown from the SOLSTICE data that we have the potential to be a best-in-class treatment and having shown very fast and deep antiviral efficacy.

Operator

Your next question comes from the line of Phil Nadeau with TD Cowen.

Philip Nadeau

Two from us. So you mentioned Astellas and Vir have noted that VIR-5500 achieved proof of concept. We're curious whether you'd be willing to share any of the criteria for proof of concept or even whether what categories were analyzed from response to duration to safety, things like that? That's the first question.

And then second, on HDV, we're curious what prelaunch activities you can do or you have been doing to work with payers and clinics to define reimbursement and identify patients. Any information you could share would be helpful.

Marianne De Backer

Yes. Thank you for those questions, Phil. On your first one, Astellas and ourselves have indeed designated VIR-5500 to have achieved a proof of concept. Obviously, I cannot go into the details of the criteria that we have preset to be achieved. But I can tell you it's really the combination holistically of the efficacy, the safety, the pharmacology, biomarker data that have led us to decide on the proof of concept being achieved.

And then as to your question on delta prelaunch activities. So we have actually done quite a bit of work already. We have done market research with health care professionals. We have done work related to payers. We have been looking at, of course, diagnosis and what is changing in that landscape.

What is very positive is, I think that post the launch of Hepcludex earlier this year by Gilead, that we have seen a market increase in HDV RNA testing. So we think that is a very positive evolution and will obviously help with diagnosis. And we have also looked into distribution channel, both for in-home administration and administration by a health care professional. So yes, quite a bit of prelaunch work that we have started that is ongoing.

Operator

Your next question comes from the line of Roanna Ruiz with Leerink.

Unknown Analyst

This is Anna on for Roanna. Just starting with 5500. Just curious, when you mentioned multiple pivotal trials are expected next year, can you help us narrow down which settings are maybe likely to lead and what remains outstanding before the first study can begin?

Marianne De Backer

Yes. Thank you, Anna. So we will be sharing more information on that, of course, together with our partner, Astellas. What I can tell you is, as you know, we are exploring VIR-5500 both for a late-line population, and that's where we achieved the Fast Track designation lately. But we're also exploring it both as monotherapy and combination in an early line set of patients. So obviously, we are aiming to target both early and late line, and we will be sharing more information on pivotal trial design in the course of next year.

Operator

Your next question comes from the line of Sean McCutchen with Raymond James.

Jacob Orkwis

Jacob Orkwis here on for Sean McCutchen. We're wondering here if we could grow a little bit into the market opportunity, specifically, if there are any early indicators you've seen from the Hepcludex launch in the U.S. and whether or not you've gotten any feedback on whether there's a desire to switch patients on to a more convenient therapy.

Marianne De Backer

Yes. Thank you. So I would say that one sort of leading indicator is that in our ECLIPSE-2 program, where we are looking to switch patients from bulevirtide patients that cannot get adequately controlled on bulevirtide to our elebsiran plus tobevibart regimen. As you have seen, we have had a very swift enrollment in that trial. So I think it's a bit of a leading indicator that there is really a need for this.

In addition, given sort of the black box warning associated with Hepcludex and the sort of anxiety around switching patients and potential flares, we are generating that data in the ECLIPSE-2 trial, and I think that will be very helpful for health care providers to use. So we think that the market opportunity for patients that, again, cannot be adequately controlled on bulevirtide or cannot take sort of the burden of a daily injection as a chronic treatment is an important opportunity for us.

Operator

Your next question comes from the line of Patrick Trucchio with H.C. Wainwright.

Luis Santos

This is Luis in for Patrick. I would continue on HDV. And can you clarify the FDA-agreed statistical hierarchy for the week 48 TND plus ALT endpoints versus TND alone? And I was wondering if you could also tell us a little bit about the finite treatment exploration for ECLIPSE-2 and ECLIPSE-3 and what qualifies the patient to stop, which agents withdrawn and how long they will be followed?

Marianne De Backer

Yes. Thank you, Luis. So as you know, as part of our registrational package for hepatitis delta, we have 3 trials with different endpoints. And what we have agreed with the FDA is that for ECLIPSE-1 and ECLIPSE-3, we have a 48-week endpoint. For ECLIPSE-2, we have a 24-week endpoint. And the endpoints are different.

For ECLIPSE-1, our primary endpoint is a combination of TND plus ALT at 48 weeks, and we have a secondary endpoint of TND alone. And then for ECLIPSE-2, we have, as I said, the endpoint is already at 24 weeks and it's only TND. And then also for ECLIPSE-3, the endpoint is at 48 weeks and it's only target not detected. So really getting rid of the virus viral elimination. So that is agreed, obviously, with the FDA. And obviously, we are looking forward to reporting out data on ECLIPSE-1 in the fourth quarter of this year and then for ECLIPSE-2 and ECLIPSE-3 in the first quarter of next year.

As to your question on finite treatment, we will be sharing more information on that in the future, but you are absolutely correct that as part of our ECLIPSE-2 and ECLIPSE-3 trial design, we are looking into that potential exploration.

Operator

Your next question comes from the line of Joseph Stringer with Needham.

Joseph Stringer

Just looking ahead to ECLIPSE-3, the head-to-head versus bulevirtide, what treatment delta on the TND primary endpoint do you consider the bar for success there? I guess how much better than bulevirtide does your combo therapy have to be on that endpoint for it to be considered clinically and commercially meaningful?

Marianne De Backer

Yes. Thank you for that question. So as you know, sort of the levels of target not detected or viral elimination that bulevirtide has been reporting depending on the dose is somewhere between 12% and 20% after 48 weeks of treatment. What we have shown in our SOLSTICE trial is target not detected levels, as mentioned earlier, after 48 weeks of around 66%. So I'm not going into the detail of how much differentiation you would need to see. But of course, on the viral efficacy level, there's a fundamental potential difference here.

Also, the frequency of administration. So bulevirtide is a daily injection that patients need to make chronically for the rest of their lives, given it's intended to be a treatment for chronic hepatitis delta. And in our case, it's monthly 2 injections. So I think from a convenience perspective, also this is fundamentally a very, very different regimen.

Operator

Your next question comes from the line of Etzer Darout with Barclays.

Etzer Darout

Just curious about the ECLIPSE-1 disclosure package for the top line. How much data can we expect there? Should we expect individual components like RNA undetectable and more normalization beyond the combined response endpoint? And also, could we learn anything about cirrhosis subgroup results as well as the full safety on the top line? Anything there would be helpful.

Marianne De Backer

Yes. Thank you, Etzer. Yes, for ECLIPSE-1, so as you know, we have approximately 120 patients in that trial, and we'll be reporting out data on that. We will be reporting out, obviously, on the primary endpoint, which is a combination of target not detected viral elimination combined with ALT normalization. And we will also be sharing information on secondary endpoints, to your point, cirrhosis, patients with cirrhosis and of course, safety and tolerability profile.

Operator

This concludes the Q&A session of the call. I will now turn it back to Kiki Patel, to close the call.

Kiki Patel

Thank you for joining us today and for your continued interest in Vir Biotechnology. We look forward to keeping you updated in the quarters ahead. This concludes today's call.