Xaira Therapeutics

Xaira Therapeutics is an American artificial-intelligence-driven biotechnology company headquartered in San Francisco and South San Francisco, California, launched in April 2024 with more than $1 billion in committed capital, the largest initial financing in ARCH Venture Partners history. The company was incubated jointly by ARCH and Foresite Labs and is led by Marc Tessier-Lavigne, the former Stanford University president and former Genentech Chief Scientific Officer. Xaira's research approach combines large-scale generative AI for protein design (built on the work of co-founder David Baker, the 2024 Nobel laureate in Chemistry, at the University of Washington Institute for Protein Design) with multi-modal biology data platforms for understanding disease mechanism. As of mid-2025 the company carried an approximately $2.7 billion valuation according to PitchBook reporting.

At a glance

• Founded: April 2024. Headquartered in South San Francisco, California.
• Status: Private. Approximately $2.7 billion valuation per mid-2025 PitchBook reporting.
• Funding: More than $1 billion in initial committed capital at launch. Co-led by ARCH Venture Partners and Foresite Labs with F-Prime, NEA, Sequoia Capital, Lux Capital, Lightspeed Venture Partners, and additional investors. Largest initial financing in ARCH Venture Partners history.
• CEO: Marc Tessier-Lavigne, Chief Executive Officer. Former Stanford University president; former Genentech Chief Scientific Officer.
• Other notable leadership: David Baker (Co-Founder; Director of the University of Washington Institute for Protein Design; 2024 Nobel laureate in Chemistry), Hetu Kamisetty (Co-Founder; former Meta and University of Washington Institute for Protein Design), Vik Bajaj (Co-Founder; Co-Founder and Chief Executive Officer of Foresite Labs; Managing Director of Foresite Capital).
• Open weights: Limited. Xaira develops commercial AI-and-biology platforms rather than open-weights model releases. Underlying protein-design research from David Baker's lab has historically been published openly.
• Flagship outputs: AI-driven protein-design and drug-discovery platform; multi-modal biology data infrastructure; therapeutic pipeline in development.

Origins

Xaira Therapeutics was launched in April 2024 with more than $1 billion in committed capital co-led by ARCH Venture Partners and Foresite Labs. The launch was the largest initial financing in ARCH's history and one of the largest biotech-launch financings on record. The launch reflected the convergence of two strategic premises: first, that generative AI for protein design had reached a commercial inflection point (a thesis subsequently validated by David Baker's 2024 Nobel Prize in Chemistry for protein design); second, that combining AI-driven protein design with multi-modal biology data infrastructure would produce a structurally different drug-discovery company than either AI-only or biology-only peers.

Marc Tessier-Lavigne joined as Chief Executive Officer at launch. Tessier-Lavigne had previously served as Stanford University president from 2016 to 2023 and as Genentech's Chief Scientific Officer from 2003 to 2011, with a long-running academic-and-industrial neuroscience and developmental-biology research career. The other co-founders include David Baker (Director of the University of Washington Institute for Protein Design and a senior figure in protein-design research, awarded the 2024 Nobel Prize in Chemistry), Hetu Kamisetty (formerly of Meta and the University of Washington Institute for Protein Design), and Vik Bajaj (Co-Founder and Chief Executive Officer of Foresite Labs and Managing Director of Foresite Capital). The launch investor cohort included F-Prime, NEA, Sequoia Capital, Lux Capital, Lightspeed Venture Partners, and additional investors alongside ARCH and Foresite.

The 2024 to 2025 period was characterized by build-out of the AI-and-biology platform and the early-pipeline therapeutic development, with the company comparatively quiet on specific pipeline disclosures in the launch period. By mid-2025 PitchBook reporting indicated an approximately $2.7 billion valuation for Xaira, reflecting subsequent financing activity and market mark-up of the launch capital.

Mission and strategy

Xaira Therapeutics's stated mission is to deliver transformative medicines by advancing and harnessing AI for drug discovery and development. The strategic premise reflects the broader Tessier-Lavigne-and-Baker-and-Foresite thesis that the convergence of generative AI for protein design with multi-modal biology data platforms enables a different drug-discovery operating model than either historical pharma operating models or the AI-only first-generation drug-discovery insurgents.

The strategy combines three threads. First, the AI-driven protein-design layer, building on David Baker's research at the University of Washington Institute for Protein Design and adjacent generative-AI methods for designing therapeutic proteins. Second, the multi-modal biology data infrastructure, which gathers genomic, proteomic, and adjacent biology data and feeds that into AI models for understanding disease causation versus correlation. Third, in-house therapeutic-pipeline development that combines the AI-and-biology platform output with traditional drug-development infrastructure.

The competitive premise positions Xaira within the AI-driven drug-discovery segment alongside Isomorphic Labs, EvolutionaryScale, Inceptive, Lila Sciences, and the broader AI-for-biology peer cohort, with the combination of Tessier-Lavigne leadership, Baker-anchored protein-design research, and the $1 billion-plus launch capital providing distinctive scale relative to peers.

Models and products

• AI-driven protein-design platform. Generative AI for designing therapeutic proteins, built on David Baker's research at the University of Washington Institute for Protein Design.
• Multi-modal biology data infrastructure. Genomic, proteomic, and adjacent biology data integrated with AI models for disease-mechanism understanding.
• Therapeutic pipeline. In-house drug-development pipeline combining the AI-and-biology platform output with traditional drug-development infrastructure. Specific pipeline disclosures have been comparatively under-disclosed publicly.

Distribution channels are direct biopharma development with potential partnership relationships with the broader pharma industry as the pipeline matures.

Pipeline and standing

Xaira's evaluation framework focuses on therapeutic-pipeline progression metrics rather than horizontal AI benchmarks. Specific pipeline disclosures have been comparatively under-disclosed publicly during the 2024 to 2025 build-out period, with industry coverage emphasizing the platform-and-team-and-capital signal rather than concrete therapeutic milestones.

Industry coverage has consistently characterized Xaira as one of the principal AI-driven drug-discovery launches of the 2024 cohort, with the $1 billion-plus initial financing, the Tessier-Lavigne leadership, and the Baker-anchored protein-design platform combining into a structurally distinctive launch profile. The 2024 Nobel Prize in Chemistry awarded to Baker for protein design has been characterized in adjacent coverage as validating the strategic premise that motivated Xaira's founding.

Leadership

As of May 2026, Xaira Therapeutics's senior leadership includes:

• Marc Tessier-Lavigne, Chief Executive Officer. Former Stanford University president; former Genentech Chief Scientific Officer.
• David Baker, Co-Founder. Director of the University of Washington Institute for Protein Design; 2024 Nobel laureate in Chemistry.
• Hetu Kamisetty, Co-Founder. Former Meta and University of Washington Institute for Protein Design.
• Vik Bajaj, Co-Founder. Co-Founder and Chief Executive Officer of Foresite Labs; Managing Director of Foresite Capital.
• Senior research, drug-development, and operating leadership across the AI-and-biology platform and the therapeutic-pipeline programs.

Continued senior research and drug-development recruitment has supported the pipeline build-out.

Funding and backers

• Launch (April 2024): More than $1 billion in initial committed capital. Co-led by ARCH Venture Partners and Foresite Labs with F-Prime, NEA, Sequoia Capital, Lux Capital, Lightspeed Venture Partners, and additional investors.
• Subsequent activity: Mid-2025 PitchBook reporting indicated an approximately $2.7 billion valuation, reflecting subsequent financing activity beyond the initial launch capital.

Cumulative disclosed private capital exceeds $1 billion. Largest initial financing in ARCH Venture Partners history.

Industry position

Xaira Therapeutics occupies a structurally distinctive position within the AI-driven drug-discovery segment: the $1 billion-plus initial financing is the largest in ARCH history and among the largest in biotech history; the Tessier-Lavigne and Baker leadership combination provides senior-pharma and senior-academic credibility; and the post-launch valuation mark-up reflects ongoing institutional-investor confidence. Industry coverage has consistently characterized Xaira as one of the principal structurally consequential AI-driven biotech launches of the 2020s.

The structural risks are characteristic of AI-driven drug-discovery companies. First, the time horizon from platform-and-team launch to clinical-pipeline progression in biotech is long, and translating the AI-and-biology platform output into clinical successes will take multiple years. Second, the AI-driven drug-discovery segment is competitive: Isomorphic Labs (a Google DeepMind spin-out backed by Alphabet), EvolutionaryScale (the protein-language-model insurgent), Inceptive, Lila Sciences, Generate Biomedicines, Insitro, Recursion Pharmaceuticals, Schrödinger, and the broader AI-for-biology cohort are all targeting overlapping segments of the AI-driven drug-discovery opportunity. Third, the AI-focused biotech segment has faced a comparatively chilly IPO and exit market through 2025 to 2026, and the path to liquidity for the launch investor cohort is not yet clear.

Competitive landscape

• Isomorphic Labs. Google DeepMind spin-out and direct AI-driven drug-discovery peer; Alphabet-backed with Demis Hassabis as senior leadership.
• EvolutionaryScale. Protein-language-model insurgent and AI-for-biology peer.
• Inceptive, Lila Sciences, Hippocratic AI, FutureHouse. AI-for-biology peers with different positioning.
• Generate Biomedicines, Insitro, Recursion Pharmaceuticals, Schrödinger. Earlier-cohort AI-driven drug-discovery peers with longer commercial track records.
• University of Washington Institute for Protein Design. Co-founder Baker's home institution and the source of the underlying protein-design research; Xaira benefits from continued cooperation with the broader UW protein-design ecosystem.
• Foresite Capital and ARCH Venture Partners portfolio companies. Adjacent biotech ventures from the launch-investor portfolios.

Outlook

• The pace of therapeutic-pipeline disclosures and the first clinical milestones from the in-house pipeline.
• Continued AI-and-biology platform research output and how the protein-design platform progresses post-Baker-Nobel-Prize.
• The competitive dynamics with Isomorphic Labs and the broader AI-for-biology peer cohort.
• The Series A or adjacent fundraising activity beyond the launch capital and the trajectory of the post-launch valuation mark-up.
• Continued senior research and drug-development recruitment.

Sources

• Business Wire: Xaira Therapeutics Launches. April 2024 launch reference.
• TechCrunch: Xaira launches with $1B. Launch coverage.
• FierceBiotech: New AI drug discovery powerhouse Xaira. Launch and team coverage.
• Genetic Engineering and Biotechnology News: AI Drug Developer Xaira launches with $1B+. Industry coverage.
• TimmermanReport: Reinventing Drug Discovery with AI: Marc Tessier-Lavigne on The Long Run. CEO interview reference.
• Foresite Capital Xaira portfolio page. Co-founder reference.