Pharma BD Deal Intelligence

GSK plc / Aiolos Bio

2024 · Acquisition/Merger · $1.0B · Complete

A $1.0B GSK acquisition of Aiolos Bio to grab AIO-001, a long-acting anti-TSLP antibody dosed as infrequently as twice yearly, aimed squarely at Amgen/AstraZeneca's Tezspire in asthma. The bet remains unproven though—AIO-001 only entered Phase 2 dosing trials in February 2025, over a year post-close.

CALLED IT — OFF BY 20
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The coverage arc

Jan 09, 2024 BioSpace Neutral

GSK puts $1.4B on the line in Aiolos acquisition to boost asthma pipeline with Phase II-ready anti-TSLP monoclonal antibody AIO-001

Feb 10, 2025 ClinicalTrials.gov (NCT06748053) - registry, Tier 4 primary Neutral

ClinicalTrials.gov NCT06748053 (Tier 4 primary registry record): Phase 2, multicentre, randomized, double-blind, placebo-controlled, dose-finding study of…

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GSK acquired Aiolos Bio for $1.0B upfront plus up to $400M in success-based regulatory milestones (announced 2024-01-09, completed 2024-02-15) to add a Phase 2-ready, long-acting anti-TSLP monoclonal antibody, AIO-001 (now GSK5784283; also SHR-1905), to its respiratory franchise. AIO-001's potency and half-life extension support potential dosing as infrequently as every six months for adult asthma, positioning GSK against Amgen/AstraZeneca's Tezspire. The asset entered a Phase 2 dose-finding asthma study (NCT06748053) in February 2025.

Key facts

Disease & market context

Severe Asthma

250K US cases/yr · $8.5B Global Severe Asthma Biologics (2025E)

Disease Overview

Severe asthma is chronic airway inflammation that remains uncontrolled despite high-dose inhaled corticosteroids plus a second controller, or requires such therapy to prevent loss of control. It affects roughly 5-10% of the ~25 million US asthma patients and is characterized by recurrent exacerbations, frequent OCS exposure, and lung function decline. Phenotypes include T2-high (eosinophilic/allergic) and T2-low disease. Biologics now target IgE (omalizumab), IL-5/IL-5R (mepolizumab, reslizumab, benralizumab), IL-4Rα (dupilumab), and TSLP (tezepelumab).

Competitive Landscape

AZ Tezspire (~$1.5B 2024) validated TSLP target. AIO-001 differentiates on dosing interval (q6m vs Tezspire q4w). Competes with anti-IL5, anti-IgE biologics.

Chronic Rhinosinusitis with Nasal Polyps

Competitive Landscape

The CRSwNP biologics market is a Type 2 inflammation battleground anchored by four approved mAbs across four distinct MOAs. Anti-IL-4Ra: Dupixent (dupilumab, Sanofi/Regeneron) is the clear category leader, approved in 2019 and generating >$14B in 2024 worldwide net sales across all indications, with CRSwNP a key growth driver. Anti-IL-5/5R: Nucala (mepolizumab, GSK) received FDA approval for CRSwNP in 2021 (Q4W subcutaneous), while Fasenra (benralizumab, AstraZeneca) failed its pivotal OSTRO trial and is not CRSwNP-approved. Anti-IgE: Xolair (omalizumab, Genentech/Novartis) was approved for CRSwNP in 2020 but has modest uptake versus dupilumab given inferior polyp-score reductions. Anti-TSLP: Tezspire (tezepelumab, Amgen/AstraZeneca) reported positive Phase 3 WAYPOINT data in CRSwNP in 2024 and filed sBLA, positioning as the upstream-alarmin alternative covering non-Type-2-high patients. Aiolos's AIO-001, a long-acting anti-TSLP mAb engineered for Q6M dosing, competes most directly with tezepelumab (Q4W) on dosing convenience and with dupilumab on breadth. Commercial threat assessment: dupilumab's biologic-experienced physician loyalty and broad atopic halo remain the dominant share anchor; AIO-001's differentiated dose interval is the only credible wedge, contingent on non-inferior SNOT-22 and NPS outcomes versus tezepelumab.

Deal timeline

Related deals — scored

DealYearValueOutcome
GSK plc / Aiolos Bio (this deal)2024$1.0B60
GSK plc / SmithKline Beecham2000$12.0B79
GSK plc / Pfizer Inc.2018$0.0M77
GSK plc / Novartis AG2014$16.0B76
GSK plc / Hansoh Pharmaceutical Group Co. Ltd.2023$1.7B74
GSK plc / Nuvalent, Inc.2026$10.6B70
GSK plc / Sierra Oncology Inc.2022$1.9B70

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