GlaxoSmithKline plc / Vir Biotechnology Inc.

Respiratory viral infections (COVID-19, influenza A/B, RSV) — neutralizing monoclonal antibodies

31M US cases/yr · $6.5B Global influenza antiviral + vaccine market 2021 (USD MM) · 570000 US COVID-19 cumulative deaths at deal date (April 2021)

Disease Overview

The expanded GSK/Vir collaboration spans COVID-19 (SARS-CoV-2), seasonal and pandemic influenza (Types A and B), and other respiratory pathogens via Vir's antibody discovery platform. COVID-19 remained the dominant immediate commercial driver at deal date — global SARS-CoV-2 cases exceeded 142 million with 3 million deaths by April 2021 (WHO), and the US had recorded ~31 million cases and ~570,000 deaths. Sotrovimab (VIR-7831/GSK4182136), the lead asset of the original 2020 collaboration, had received Emergency Use Authorization on May 26, 2021 (just after deal announcement) for high-risk non-hospitalized COVID-19 based on COMET-ICE (85% reduction in hospitalization or death). Influenza, the second-largest scope, causes 9-41 million US cases, 140,000-710,000 hospitalizations and 12,000-52,000 deaths annually per CDC, with current standard of care primarily neuraminidase inhibitors (oseltamivir/Tamiflu, peramivir, zanamivir/Relenza) and the cap-dependent endonuclease inhibitor baloxavir (Xofluza). Existing seasonal influenza vaccines deliver inconsistent efficacy (40-60% in good-match years, 10-30% in mismatched seasons) and no broadly protective long-acting prophylactic exists. RSV had no approved therapeutic at deal date for adults; Synagis (palivizumab) was approved only for high-risk pediatrics. The respiratory antibody opportunity at deal date was framed as building durable monoclonal protection for at-risk populations across multiple pathogens.

Competitive Landscape

At deal date (April 2021) the COVID-19 antibody market was bracketed by Lilly bamlanivimab/etesevimab (FDA EUA February 2021), Regeneron casirivimab/imdevimab (REGEN-COV, FDA EUA November 2020), AstraZeneca tixagevimab/cilgavimab (Evusheld, Phase 3 PROVENT, EUA December 2021), Brii Biosciences amubarvimab/romlusevimab (BRII-196/198), and Vir/GSK sotrovimab (VIR-7831, EUA May 2021). The class was rapidly displaced by viral evolution: Lilly products lost EUA in January 2022 (Omicron-resistant), AstraZeneca Evusheld lost EUA in January 2023, sotrovimab lost EUA against BA.2 in April 2022, and oral antivirals Paxlovid (Pfizer) and Lagevrio (Merck) emerged as standard outpatient SOC. For influenza antibodies the competitive set included Vir VIR-2482 (Phase 2 in healthy adults, terminated October 2023 after missing endpoint), Genentech MHAA4549A (discontinued), Regeneron REGN3933/REGN3944 (discontinued), MedImmune/AstraZeneca MEDI8852 (Phase 2, partnered with Sanofi nirsevimab for RSV), Visterra/Otsuka VIS410 (discontinued), and Adagio/Invivyd ADG20 (later adintrevimab, FDA decision deferred). For RSV the field rapidly shifted to vaccines: GSK Arexvy (FDA May 2023, age 60+), Pfizer Abrysvo (FDA May 2023, age 60+ and maternal), Sanofi/AstraZeneca Beyfortus nirsevimab (FDA July 2023, infant prophylaxis). Vir's broader platform leverages systematic screening of B-cell repertoires from convalescent and hyper-immunized donors, with extensive computational engineering for half-life extension and Fc effector function tuning.