Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors) - Target Population, Competitive Landscape, and Market Forecast - 2034

Key Highlights:

• Anti-thymic stromal lymphopoietin (TSLP) therapies are also expected to enter the COPD market. The TSLP pathway is validated with one FDA-approved therapy in asthma (TEZSPIRE [tezepelumab]).
• TSLP is a central mediator in atopic diseases, making it an attractive therapeutic target. However, the development of small-molecule inhibitors has been hindered by the structural complexity of TSLP and the difficulty of disrupting its protein-protein interaction with the receptor complex, limiting current strategies to biologics.
• As an upstream driver of both T2 and non-T2 inflammation, TSLP activates multiple immune pathways implicated in asthma and COPD. Targeting TSLP offers broader and more effective immunomodulation than interleukin-specific therapies, positioning it as a strategic therapeutic target across heterogeneous airway diseases.
• AstraZeneca and Amgen's TEZSPIRE is being evaluated for COPD, but Uniquity Bio's Solrikitug may represent a more potent TSLP-targeting alternative. In early clinical studies, Solrikitug has shown 15-fold greater potency than TEZSPIRE in inhibiting TSLP-dependent cell proliferation and TARC expression. While these results are promising, Solrikitug remains in mid-stage development, and its long-term efficacy and clinical differentiation will require further validation.
• As an upstream regulator in the inflammatory cascade, TSLP represents a strategic target whose receptor blockade may enable a single therapy to modulate multiple pathogenic inflammatory processes across a wide range of diseases.
• Key players in the TSLP inhibitors market include Sanofi, Uniquity Bio, Upstream Bio, Keymed Biosciences, Belenos Bioscience, Biosion, Pfizer, and other companies that are developing TSLP inhibitors covering various indications.

DelveInsight's "Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors) - Target Population, Competitive Landscape, and Market Forecast - 2034" report delivers an in-depth understanding of the TSLP Inhibitors, historical and competitive landscape as well as the TSLP Inhibitors market trends in the United States, EU4 (Germany, France, Italy, and Spain) and the United Kingdom, and Japan.

The TSLP Inhibitors market report provides current treatment practices, emerging drugs, market share of individual therapies, and current and forecasted 7MM TSLP inhibitors market size from 2020 to 2034. The report also covers current TSLP Inhibitors treatment practices/algorithms and unmet medical needs to curate the best opportunities and assess the market's potential.

Geography Covered:

• The United States
• EU4 (Germany, France, Italy, and Spain) and the United Kingdom
• Japan

Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors) Understanding

TSLP Overview

TSLP is an epithelium-derived cytokine that plays a pivotal role in orchestrating Th2-mediated immune responses. Structurally related to interleukin-7 (IL-7), TSLP signals through a heterodimeric receptor complex composed of the TSLP receptor (TSLPR) and IL-7 receptor alpha (IL-7Ra). This receptor complex is broadly expressed across a range of immune and non-immune cells, including dendritic cells, macrophages, T cells, epithelial cells, and neurons. Upon ligand binding, the receptor activates downstream signaling cascades involving STAT3, STAT5, STAT6, and GATA3, culminating in the production of Th2 cytokines such as IL-4 and IL-13. TSLP also drives the activation of dendritic cells, which in turn prime naive CD4+ T cells toward a Th2 phenotype within draining lymph nodes. Furthermore, TSLP signaling is critical for the formation of Th2 memory cells and the activation of group 2 innate lymphoid cells, both key contributors to sustained inflammation in atopic diseases. Given its central role in the pathogenesis of allergic and inflammatory conditions, TSLP has emerged as a promising therapeutic target. However, the development of small-molecule TSLP inhibitors remains elusive, largely due to the inherent difficulty of disrupting the protein-protein interactions between TSLP and its receptor complex.

Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors) Epidemiology

The TSLP inhibitors epidemiology chapter in the report provides historical as well as forecasted epidemiology segmented as total cases of selected indication for TSLP inhibitors, total eligible patient pool for TSLP inhibitors in selected indication, total treated cases in selected indication for TSLP inhibitors in the 7MM covering the United States, EU4 (Germany, France, Italy, and Spain), and the United Kingdom, and Japan from 2020 to 2034.

• The total number of diagnosed prevalent cases of COPD in the 7MM was approximately 31 million in 2024.
• Among EU4 and the UK, the UK accounted for the highest diagnosed prevalent cases of asthma in 2024, with ~8.4 million cases, followed by Germany. On the other hand, Spain accounted for the least cases.
• Japan accounted for approximately 9 million cases of atopic dermatitis in 2024.

Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors) Drug Chapters

The drug chapter segment of the TSLP inhibitors reports encloses a detailed analysis of TSLP inhibitors in different stages of development. It also helps understand the TSLP inhibitors clinical trial details, expressive pharmacological action, agreements and collaborations, approval and patent details, advantages and disadvantages of each included drug and the latest news and press releases.

Marketed Drugs

TEZSPIRE (tezepelumab): Amgen/AstraZeneca

TEZSPIRE is a first-in-class human mAb that inhibits the action of TSLP, a key epithelial cytokine that sits at the top of multiple inflammatory cascades and is critical in the initiation and persistence of allergic, eosinophilic, and other types of epithelial-driven inflammation associated with severe asthma and other inflammatory diseases. TEZPIRE received asthma approval in 2021 and is currently in COPD development.

In July 2024, AstraZeneca announced that the US FDA granted a Breakthrough Therapy Designation (BTD) for tezepelumab for the add-on maintenance treatment of patients with moderate-to-very severe COPD characterized by an eosinophilic phenotype.

In February 2023, Amgen and AstraZeneca announced that TEZSPIRE for self-administration in a prefilled, single-use pen for patients aged 12 years and older with severe asthma received approval from the US FDA.

Emerging Drugs

Verekitug (UPB-101): Upstream Bio

Verekitug is a novel, fully human recombinant IgG1 mAb that targets the human TSLP Receptor (TSLPR), thereby blocking downstream signaling. In preclinical studies, verekitug effectively inhibited cytokine production from both CD4+ T cells and Type II Innate Lymphoid Cells (ILC2), indicating its potential efficacy against a broad range of inflammatory responses. Results from three completed Phase I studies in asthma have shown that verekitug is safe and well-tolerated. Verekitug is also being developed for moderate-to-severe COPD, currently in Phase II clinical development.

In September 2024, Upstream Bio presented interim 32-week Phase Ib data for verekitug (UPB-101), a next-generation TSLP receptor antagonist, at the ERS Congress, highlighting its potential to deliver sustained biomarker reductions and robust target engagement in patients with asthma.

Lunsekimig (SAR443765): Sanofi

Lunsekimig is a novel nanobody VHH designed to simultaneously target IL-13, a key driver of tissue damage in respiratory diseases, and TSLP, an upstream initiator of inflammation. Preclinical studies suggest that dual inhibition of these pathways may offer additive or synergistic benefits in immune-mediated conditions such as asthma. Lunsekimig is currently in clinical development, and its safety and efficacy have not yet been evaluated by regulatory authorities.

Sanofi announced that the first patient has been enrolled in the Phase IIb asthma trial, with data expected in 2026.

Sanofi plans to initiate Phase II/III trial for COPD, to start in 2026.

Solrikitug: Uniquity Bio

Solrikitug is a highly potent anti-TSLP monoclonal antibody, which prevents the binding of TSLP to its receptors. Given TSLP's position as the "master switch" cytokine sitting at the top of the inflammatory cascade, solrikitug could have potential utility in a wide array of immunology and inflammation programs. Solrikitug was in-licensed from Merck.

In May 2024, Blackstone announced funding of up to USD 300 million to Uniquity Bio set to start Phase II clinical trials in COPD and Asthma with novel Anti-TSLP mAb.

Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors) Market Outlook

TSLP inhibitors, led by TEZSPIRE (tezepelumab), have secured a strong position in severe asthma as add-on biologics effective across phenotypes, including patients with low eosinophils or FeNO, offering an advantage over IL-5 and IL-4/13-targeted agents. In COPD, large trials have shown mixed overall results but demonstrated clinically relevant benefit in eosinophil-high subgroups, suggesting a likely biomarker-driven niche if approved; in the meantime, some clinicians may explore off-label use in such high-risk COPD patients with frequent exacerbations despite maximal inhaled therapy. In atopic dermatitis, despite a clear mechanistic rationale, tezepelumab failed to meet efficacy endpoints in mid-stage studies, limiting short-term prospects, though next-generation molecules or combination regimens remain under investigation. The development pipeline features mAbs, Solrikitug (COPD, asthma), Verekitug (moderate-to-severe COPD, severe asthma), and Bosakitug (atopic dermatitis), as well as next-generation multi-specific formats, including the bispecific nanobody Lunsekimig (moderate-to-severe asthma, COPD), the bispecific antibody CM512 (moderate-to-severe COPD), and the trispecific antibody PF-07275315 (mild-to-severe atopic dermatitis), all in mid-stage clinical trials.

Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors) Drugs Uptake

This section focuses on the uptake rate of potential emerging TSLP inhibitors expected to be launched in the market during 2025-2034.

Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors) Pipeline Development Activities

The report provides insights into different therapeutic candidates in Phase III, Phase II, and Phase I. It also analyzes key players involved in developing targeted therapeutics.

The presence of numerous drugs under different stages is expected to generate immense opportunity for TSLP inhibitors market growth over the forecast period.

Pipeline development activities

The report covers information on collaborations, acquisitions and mergers, licensing, and patent details for TSLP inhibitors emerging therapies.

The increasing strategic collaborations among major market players to enhance the growth of their pipeline products are anticipated to drive market expansion.

KOL Views

To keep up with current and future market trends, we take Industry Experts' opinions working in the domain through primary research to fill the data gaps and validate our secondary research. Industry experts were contacted for insights on TSLP evolving treatment landscape, patient reliance on conventional therapies, patient therapy switching acceptability, drug uptake, along challenges related to accessibility.

DelveInsight's analysts connected with 25+ KOLs to gather insights; however, interviews were conducted with 10+ KOLs in the 7MM. Centers such as Freie Universitat of Berlin, University of California, Royal Brompton and Harefield Hospitals, Universite de Toulouse, Universite de Lille, etc. were contacted.

Their opinion helps understand and validate current and emerging therapy treatment patterns or TSLP inhibitors market trends. This will support the clients in potential upcoming novel treatments by identifying the overall scenario of the market and the unmet needs.

Qualitative Analysis

We perform Qualitative and market Intelligence analysis using various approaches, such as SWOT analysis and Conjoint Analysis. In the SWOT analysis, strengths, weaknesses, opportunities, and threats in terms of gaps in disease diagnosis, patient awareness, physician acceptability, competitive landscape, cost-effectiveness, and geographical accessibility of therapies are provided.

Conjoint Analysis analyzes multiple approved and emerging therapies based on relevant attributes such as safety, efficacy, frequency of administration, route of administration, and order of entry. Scoring is given based on these parameters to analyze the effectiveness of therapy. In efficacy, the trial's primary and secondary outcome measures are evaluated; for instance, in event-free survival, one of the most important primary outcome measures is event-free survival and overall survival.

Further, the therapies' safety is evaluated, wherein the acceptability, tolerability, and adverse events are majorly observed, and it sets a clear understanding of the side effects posed by the drug in the trials. In addition, the scoring is also based on the probability of success and the addressable patient pool for each therapy. According to these parameters, the final weightage score and the ranking of the emerging therapies are decided.

Market Access and Reimbursement

Reimbursement may be referred to as the negotiation of a price between a manufacturer and payer that allows the manufacturer access to the market. It is provided to reduce the high costs and make the essential drugs affordable. Health technology assessment (HTA) plays an important role in reimbursement decision-making and recommending the use of a drug. These recommendations vary widely throughout the seven major markets, even for the same drug.

In the US healthcare system, both Public and Private health insurance coverage are included. Also, Medicare and Medicaid are the largest government-funded programs in the US. The major healthcare programs including Medicare, Medicaid, the Children's Health Insurance Program (CHIP), and the state and federal health insurance marketplaces are overseen by the Centers for Medicare & Medicaid Services (CMS). Other than these, Pharmacy Benefit Managers (PBMs), and third-party organizations that provide services, and educational programs to aid patients are also present.

The report further provides detailed insights on the country-wise accessibility and reimbursement scenarios, cost-effectiveness scenario of approved therapies, programs making accessibility easier and out-of-pocket costs more affordable, insights on patients insured under federal or state government prescription drug programs, etc.

Key Updates on Thymic Stromal Lymphopoietin Inhibitors (TSLP inhibitors)

• In June 2025, Upstream Bio presented pharmacology modeling data at the European Academy of Allergy and Clinical Immunology (EAACI) Congress, demonstrating that targeting the TSLP receptor with verekitug may offer greater potency compared to approaches focused on the TSLP ligand.
• In May 2025, AstraZeneca announced presentation of COURSE Phase IIa trial data OF TEZSPIRE at ATS 2025.
• In April 2025, Biosion and Aclaris Therapeutics announced they have received clearance from the US FDA for its Investigational New Drug (IND) application to initiate a Phase Ia/Ib clinical trial of ATI-052 (BSI-502), a potential best-in-class bispecific anti-TSLP/IL-4R mAb.

Scope of the Report:

• The report covers a segment of key events, an executive summary, and a descriptive overview of the TSLP Inhibitor, explaining its mechanism, and emerging TSLP inhibitors.
• Comprehensive insight into the competitive landscape, and forecasts, the future growth potential of treatment rate, drug uptake, and drug information have been provided.
• Additionally, an all-inclusive account of the current and emerging therapies and the elaborative profiles of late-stage and prominent therapies will impact the current landscape.
• A detailed review of the TSLP Inhibitor market, historical and forecasted market size, market share by therapies, detailed assumptions, and rationale behind our approach is included in the report, covering the 7MM drug outreach.
• The report provides an edge while developing business strategies, by understanding trends, through SWOT analysis, expert insights/KOL views, and treatment preferences that help shape and drive the 7MM TSLP Inhibitor market.

TSLP Inhibitors Report Insights

• TSLP Inhibitors Targeted Patient Pool
• Therapeutic Approaches
• TSLP Inhibitors Pipeline Analysis
• TSLP Inhibitors Market Size and Trends
• Existing and future Market Opportunity

TSLP Inhibitors Report Key Strengths

• Ten years Forecast
• 7MM Coverage
• Key Cross Competition
• Drugs Uptake and Key Market Forecast Assumptions

TSLP Inhibitors Report Assessment

• Current Treatment Practices
• Unmet Needs
• Pipeline Product Profiles
• Market Attractiveness
• Qualitative Analysis (SWOT and Conjoint Analysis)

Key Questions:

• What was the TSLP inhibitor total market size, the market size by therapies, market share (%) distribution, and what would it look like in 2034? What are the contributing factors for this growth?
• Which drug is going to be the largest contributor in 2034?
• Which is the most lucrative market for TSLP Inhibitors?
• What are the pricing variations among different geographies?
• What are the risks, burdens, and unmet needs of treatment for TSLP inhibitors? What will be the growth opportunities across the 7MM for the patient population of TSLP inhibitors?
• What are the key factors hampering the growth of the TSLP inhibitors market?
• What key designations have been granted to TSLP inhibitors?
• Patient acceptability in terms of preferred therapy options as per real-world scenarios?

Reasons to buy:

• The report will help develop business strategies by understanding the latest trends and changing dynamics driving the TSLP inhibitors market.
• Understand the existing market opportunities in varying geographies and the growth potential over the coming years.
• Distribution of historical and current patient share based on real-world prescription data along with reported sales of approved products in the US, EU4 (Germany, France, Italy, and Spain) the United Kingdom, and Japan.
• Identifying strong upcoming players in the market will help devise strategies to help get ahead of competitors.
• Detailed analysis and ranking of indication-wise current and emerging therapies under the conjoint analysis section to provide visibility around leading indications.
• Highlights of Access and Reimbursement policies of approved therapies, barriers to accessibility of expensive off-label therapies, and patient assistance programs.
• To understand Key Opinion Leaders' perspectives around the accessibility, acceptability, and compliance-related challenges of existing treatment to overcome barriers in the future.
• Detailed insights on the unmet needs of the existing market so that the upcoming players can strengthen their development and launch strategy.