What Rapt Therapeutics does

Rapt Therapeutics was a clinical-stage biopharmaceutical company focused on the discovery and development of immunology-based therapeutics for inflammatory and immunological diseases. Founded in 2015 and headquartered in South San Francisco, California, the company was publicly traded on NASDAQ under the ticker RAPT prior to its March 2026 acquisition by GSK plc. Its lead asset, ozureprubart (formerly RPT904/JYB1904), is a novel half-life extended monoclonal antibody designed to bind free human IgE, a key driver of allergic diseases. Compared to first-generation anti-IgE therapy omalizumab (Xolair), ozureprubart demonstrated extended pharmacokinetic and pharmacodynamic properties supporting potential dosing every 8-12 weeks versus every 2-4 weeks for omalizumab, and offered a path to treat patients currently ineligible for omalizumab due to high IgE levels or body weight. The company also held a granted patent on fused ring imidazole compounds acting as TNF-alpha modulators with applications across cancer, autoimmune, metabolic, and neurological disorders.

Rapt's pipeline targeted two primary indications: food allergy (peanut, milk, egg, cashew, walnut) and chronic spontaneous urticaria (CSU). A Phase 2 trial in 137 CSU patients demonstrated comparable efficacy and safety to omalizumab with durable effects after a single dose, and the FDA cleared an Investigational New Drug application in September 2025 to proceed to the Phase 2b prestIgE food allergy trial, which was initiated in October 2025 across sites in the U.S., Canada, and Australia with results expected in 2027. Rapt partnered with Shanghai Jeyou Pharmaceutical for development and commercialization in China, where the asset advanced to Phase 3.

As a pre-revenue clinical-stage company, Rapt generated no product sales and funded operations through multiple capital raises totaling approximately $668.7 million across public offerings in June 2021 ($143.7M), November 2022 ($75M), and October 2025 ($250M), plus private placements in May 2022 ($50M PIPE led by Redmile Group) and December 2024 ($150M). The company was acquired by GSK plc in January 2026 for approximately $2.2 billion ($58 per share, a ~65.2% premium), with the deal closing in March 2026 and RAPT delisting from Nasdaq to become a wholly owned subsidiary of GSK.

Name

Rapt Therapeutics

Legal name

RAPT Therapeutics, Inc.

Website

https://rapt.com

Company type

Public

Founded year

2015

Operating status

Acquired

Headcount range

101–250 employees

Short description

Rapt Therapeutics was a clinical-stage biopharmaceutical company developing ozureprubart, a long-acting anti-IgE monoclonal antibody for food allergy and chronic spontaneous urticaria. The pre-revenue South San Francisco-based company was acquired by GSK in 2026 for $2.2 billion.

Ownership category

akta.pro rank

Product category

Immunology Biopharmaceutical Therapeutics

NAICS

Biological Product (except Diagnostic) Manufacturing (325414), Research and Development in Biotechnology (except Nanobiotechnology) (541714)

SIC

Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

Monoclonal Antibody Therapeutics (mAbs) (HLAAAAAA)

Keywords

• Clinical-stage biopharmaceuticals
• Monoclonal antibody therapy
• Anti-IgE therapeutics
• Allergic disease treatments
• Immunology drug development

Headquarters

HQ city

South San Francisco

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales

Revenue model

1. Biopharmaceutical Product Revenue: RAPT Therapeutics was a clinical-stage biopharmaceutical company with no commercialized products. The company was developing ozureprubart for food allergy and chronic spontaneous urticaria. Revenue was expected to come from product sales following regulatory approval. The company was acquired by GSK in March 2026 before commercializing any products.

Go-to-market motion1 record

Marketing channels3 records

Core offering

RAPT Therapeutics was a clinical-stage biopharmaceutical company developing immunology-based therapeutics for inflammatory and immunological diseases. Its lead product candidate, ozureprubart (RPT904/JYB1904), is a half-life extended anti-IgE monoclonal antibody in Phase 2b development for food allergy protection and previously tested in Phase 2 for chronic spontaneous urticaria, with future revenue expected from product sales following regulatory approval.

Product overview

RAPT Therapeutics is a clinical-stage biopharmaceutical company focused on developing immunology-based therapies for inflammatory and immunological diseases. The company's primary product is ozureprubart (formerly RPT904/JYB1904), a long-acting anti-IgE monoclonal antibody in Phase 2b development for food allergy protection and previously completed Phase 2 trials for chronic spontaneous urticaria (CSU). The company was acquired by GSK in January 2026 for approximately $2.2 billion.

Differentiator

Problem solved

Functional benefit

Products and services

• Ozureprubart (RPT904/JYB1904) A novel half-life extended monoclonal antibody (mAb) designed to bind free human IgE for the treatment of allergic inflammatory diseases including food allergy and chronic spontaneous urticaria. Designed to be dosed every 8-12 weeks versus every 2-4 weeks for omalizumab (Xolair), with potential to treat patients currently ineligible for omalizumab due to high IgE or body weight.

Quantifiable outcome

• Phase 2 trial in 137 CSU patients showed durable efficacy out to 16 weeks comparable to omalizumab dosed every 4 weeks
• +2 more outcomes

Named customers2 records

Segments2 records

Ideal customer profiles1 record

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature2 records

Partnerships

One partnership is on record.

• Shanghai Jeyou PharmaceuticalcoreStrategic or Co-development Partner · 20 October 2025RAPT Therapeutics partnered with Shanghai Jeyou Pharmaceutical for the development of RPT904 (JYB1904/ozureprubart) in China. The partnership achieved positive topline data from a Phase 2 trial in chronic spontaneous urticaria in October 2025, demonstrating comparable efficacy and safety to omalizumab with durable effects after a single dose. Jeyou advanced RPT904 to Phase 3 development in China.

Scale indicators8 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Sanofi / Regeneron: Co-developers of Dupixent (dupilumab), a leading IL-4/IL-13 biologic approved across multiple type-2 inflammatory indications including CSU-adjacent conditions. Dupixent represents the most relevant therapeutic competitor and emerging standard of care in several allergic indications RAPT targets.
• Aimmune Therapeutics (Nestlé Health Science): Developer of Palforzia, the first FDA-approved oral immunotherapy for peanut allergy. Aimmune competes directly in RAPT's food allergy indication with a fundamentally different mechanism (desensitization vs. IgE blockade).
• Genentech (Roche) / Novartis: Co-developers and marketers of omalizumab (Xolair), the incumbent anti-IgE monoclonal antibody and direct competitive benchmark for ozureprubart across CSU, food allergy, and severe asthma. Any ozureprubart commercial profile is measured against Xolair's safety, efficacy, and real-world experience base.

Emerging players

• Alladapt Immunotherapeutics: Clinical-stage company developing multi-food oral immunotherapy (ADP101) covering peanut plus other priority food allergens. Targets the same multi-food allergy patient population as ozureprubart's prestIgE trial.
• DBV Technologies: Developer of Viaskin, an epicutaneous immunotherapy patch for peanut and other food allergies. DBV competes in the same pediatric/adolescent food allergy treatment market with a non-injectable alternative modality.

Broad incumbents

• AstraZeneca: Through Amgen partnership, markets Tezspire (tezepelumab) in severe asthma and has broader respiratory/immunology franchise. AstraZeneca competes in the same prescriber base and biologic allergic disease treatment paradigm as ozureprubart.
• UCB: Global biopharmaceutical company with immunology franchise including Cimzia and growing presence in atopic diseases. Operates in overlapping prescriber and payer ecosystems in chronic allergic conditions targeted by ozureprubart.
• Stallergenes Greer: Established allergy immunotherapy company offering subcutaneous and sublingual immunotherapy products across a range of allergens. Operates in adjacent allergy treatment paradigms and shares allergist prescriber relationships with RAPT.

Regional players

• LEO Pharma: Dermatology-focused biopharma with atopic dermatitis portfolio (Adbry/adtralza). While more regionally concentrated, LEO Pharma represents an adjacent competitor in the broader type-2 inflammation treatment landscape relevant to chronic allergic diseases.

Others

• GlaxoSmithKline (GSK): Acquirer of RAPT Therapeutics for $2.2B in 2026. GSK is the parent company and now controls global development and commercialization of ozureprubart outside of greater China, making it the most strategically relevant entity for understanding post-acquisition value capture.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat3 records

Key risks5 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/@rapttherapeutics
• LinkedInlinkedin.com/company/rapt

Revenue estimate

Valuation estimate

Number of profiles

Profiles8 records

Funding overview

Funding rounds10 records

Investors16 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Rapt Therapeutics