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Acquisition includes ozureprubart, a potentially best-in-class anti-IgE antibody, in development for prophylactic protection against food allergens
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Ozureprubart offers potential to protect against food allergy reactions with less frequent dosing compared to existing standard-of-care therapy
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Food allergies are increasing with significant unmet need and serious health risks
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Acquisition adds to Respiratory, Immunology & Inflammation pipeline
20 January 2026--GSK plc (LSE/NYSE: GSK) today announced that it has entered a definitive agreement to acquire RAPT Therapeutics (“RAPT”) (NASDAQ: RAPT), a California-based, clinical-stage biopharmaceutical company dedicated to developing novel therapies for patients living with inflammatory and immunologic diseases. The acquisition includes ozureprubart, a long-acting anti-immunoglobulin E (IgE) monoclonal antibody, currently in phase IIb clinical development for prophylactic protection against food allergens.
IgE is a clinically validated target and is the only approved systemic therapy shown to protect patients from a harmful allergic and inflammatory immune response. Around 94% of severe food allergies are caused by IgE-mediated reactions.1
Current anti-IgE treatment for food allergy involves injections every 2 to 4 weeks, which can be a significant burden, particularly since most patients are children. Ozureprubart’s clinical profile offers the potential for less frequent dosing of every 12 weeks, supporting improved compliance and patient outcomes; as well as providing a new option to approximately 25% of patients currently ineligible for existing therapy. Ozureprubart complements GSK’s extensive commercial footprint and prescriber base in allergy.
Data from the phase IIb trial (prestIgE) assessing use of ozureprubart as monotherapy is expected in 2027, with phase III trials to be focused on both at-risk adult and paediatric populations. In the US, over 17 million people are diagnosed with food allergies, with more than 1.3 million people suffering severe reactions.2,3,4 This results in more than 3 million patient visits each year to hospital and emergency care.5
Tony Wood, Chief Scientific Officer, GSK said: “The addition of ozureprubart brings another promising new, potential best-in-class treatment to GSK’s pipeline. Food allergies cause severe health impacts to patients with existing treatment requiring injections as frequently as every 2 weeks. Ozureprubart offers the opportunity to bring sustained protection to patients with dosing every 12 weeks, and is consistent with our approach to acquire assets that address validated targets and where there is clear unmet medical need.”
Brian Wong, President & Chief Executive Officer, RAPT Therapeutics, said: “We are excited to enter into this agreement with GSK, which offers an attractive path forward for our programs, particularly the opportunity we envision for ozureprubart in food allergy. This transaction has the potential to provide access to the global development and commercialisation capabilities, resources and infrastructure that GSK has to offer and ultimately bring added value to our pipeline, patients and stockholders.”
Financial considerations
Under the terms of the agreement, GSK will pay RAPT Therapeutics shareholders $58.00 per share at closing for an estimated aggregate equity value of $2.2 billion. Net of cash acquired, GSK’s estimated upfront investment is $1.9 billion.
The transaction gives GSK the global rights to the ozureprubart programme, excluding mainland China, Macau, Taiwan and Hong Kong. GSK will also be responsible for success-based milestone and royalty payments for ozureprubart owed to RAPT’s partner, Shanghai Jeyou Pharmaceutical Co., Ltd.
Under the terms of the agreement, GSK’s subsidiary is obligated to commence a tender offer to acquire all outstanding shares of RAPT common stock for $58.00 per share in cash within 10 business days of signing. The transaction is subject to customary closing conditions, including the tender of a majority of RAPT’s outstanding shares of common stock in the tender offer and expiration or termination of the applicable waiting period under the under the Hart-Scott-Rodino Act in the US. Promptly following the closing of the tender offer, GSK will acquire any shares of RAPT that are not tendered in the tender offer through a second-step merger under Delaware law at the tender offer price. GSK will account for the transaction as a business combination.
The transaction is expected to close in the first quarter of 2026.
About food allergies
In the US, over 17 million people are diagnosed with food allergies, with more than 1.3 million people suffering severe reactions.2,3,4 Notably, 65% of severe food allergy patients are children and adolescents.1 This results in more than 3 million patient visits each year to hospital and emergency care.5 Disease burden is amplified by the frequency and complexity of allergic reactions, which can escalate to anaphylaxis, emergency care and impact a patient’s wellbeing and participation in social activities. Collectively, food allergies cost US families an estimated $33 billion in 2024, underscoring the need for more effective and durable therapies.5
About RAPT Therapeutics
RAPT Therapeutics is a clinical-stage immunology-based biopharmaceutical company focused on discovering, developing and commercializing novel therapies for patients living with inflammatory and immunologic diseases. Utilizing deep and proprietary expertise in immunology, RAPT develops novel molecules that are designed to modulate the critical immune responses underlying these diseases.
About GSK
GSK is a global biopharma company with a purpose to unite science, technology, and talent to get ahead of disease together.
References
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GSK Epi assessment based on MarketScan and Optum claims database
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Warren CM, Aktas ON, Manalo LJ, Bartell TR, Gupta RS. The epidemiology of multifood allergy in the United States: a population-based study. Ann Allergy Asthma Immunol. 2023;130(5):637-648.e5.
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US Census Bureau. Age and Sex, American Community Survey, ACS 1-Year Estimates Subject Tables, Table S0101, 2022. Accessed 9 January, 2026. https://data.census.gov/table/ACSST1Y2022.S0101.
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MarketScan's overall prevalence, and Optum’s age-stratified (<18; 18+) and overall prevalence. Severe FA defined as patients with ER/inpatient visit or under specialist care.
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FARE Food Allergy Facts and Statistics for the US (April 2024).