Lymphocyte-Activation Gene 3 (LAG-3) -Target Population, Competitive Landscape, and Market Forecast-2034

Key Highlights:

• LAG-3 is a transmembrane molecule that is expressed on CD4+ and CD8+ T cells, natural killer T (NKT) cells, natural killer (NK) cells, plasmacytoid dendritic cells (pDCs), and regulatory T cells (Tregs).
• There is also an expansion of LAG-3 immune checkpoints in other indications that may be a significantly promising immune checkpoint, to suppress T-cell activation and cytokine secretion, thereby ensuring a state of immune homeostasis.
• LAG-3 targeting therapies are effective treatments for melanoma, non-small cell lung cancer (NSCLC), breast cancer, urothelial cancer, head and neck squamous cell carcinoma (HNSCC), ulcerative colitis, autoimmune diseases, psoriasis, and others.
• LAG-3 blockade has been shown to reinvigorate T-cell anti-tumor responses in vivo, though its mechanisms remain incompletely defined. Given the impact of checkpoint inhibitors in hard-to-treat cancers like melanoma, LAG-3 is emerging as a promising target. This review analyzes its therapeutic potential and recent clinical progress.
• OPDUALAG, the first approved drug targeting LAG-3, combines nivolumab (a PD-1 inhibitor) with relatlimab (a LAG-3 blocker). According to the National Cancer Institute, it is approved for the treatment of unresectable or metastatic melanoma.
• OPDUALAG's impressive US sales of USD 870 million in 2024-reflecting a 41% year-over-year growth-highlight not only its strong commercial momentum but also a broader validation of dual immune checkpoint inhibition targeting PD-1 and LAG-3. This surge reinforces OPDUALAG's emergence as a blockbuster therapy and signals the growing clinical and market interest in LAG-3 as the next frontier in immuno-oncology, particularly following the saturation of first-generation PD-(L)1 monotherapies.
• However, OPDUALAG's trajectory is unlikely to remain unchallenged. The LAG-3 inhibitor landscape is rapidly evolving, with Regeneron positioning itself as the most formidable competitor. Its regimen-fianlimab (anti-LAG-3) +- LIBTAYO (anti-PD-1)-is under investigation for NSCLC and melanoma, signaling high internal confidence and an aggressive strategy to capture market share. Given Regeneron's established oncology portfolio and commercial infrastructure, fianlimab could potentially rival OPDUALAG, particularly if it demonstrates superior efficacy, safety, or biomarker-driven selectivity.
• Beyond Regeneron, a second tier of players is also intensifying competition. Immutep is establishing a strong presence in the LAG-3 space, advancing a diverse pipeline including eftilagimod alpha (IMP321), IMP761, LAG525 (with Novartis), and IMP731, targeting a broad range of indications from solid tumors like NSCLC and triple-negative breast cancer (TNBC) to autoimmune diseases such as psoriasis, ulcerative colitis. Ono Pharma's ONO-4482/relatlimab, Agenus and Incytes's INCAGN2385, and others are advancing through mid- and early-stage clinical development.
• Overall the pipeline has promising products with differentiated mechanisms-some featuring bispecific or multi-target formats-that may confer added value in tumor microenvironments resistant to current checkpoint inhibitors. These programs, while less advanced, reflect a wider industry bet on LAG-3 as a viable immuno-oncology axis, suggesting that BMS's first-mover advantage with OPDUALAG may be time-limited unless it expands indications or enhances its clinical profile through combinations or biomarker strategies.
• Although combination immunotherapy is an obvious strategy to pursue, the fact that there have been more failures than successes in this effort has served as a wake-up call, emphasizing the importance of building a solid scientific foundation for the development of next-generation immuno-oncology (IO) agents. Furthermore, there are several other immune checkpoint receptors (TGIT, TIM-3) that can compete with LAG-3 products in the future.

DelveInsight's "Lymphocyte-Activation Gene 3 (LAG-3) -Target Population, Competitive Landscape, and Market Forecast-2034" report delivers an in-depth understanding of the LAG-3, historical and Competitive Landscape, and LAG-3 market trends in the United States, EU4 (Germany, France, Italy, and Spain), the United Kingdom, and Japan.

The LAG-3 market report provides current treatment practices, emerging drugs, market share of individual therapies, and current and forecasted 7MM LAG-3 market size from 2020 to 2034. The report also covers current LAG-3 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

Study Period: 2020-2034

Lymphocyte-Activation Gene 3 (LAG-3) Understanding

Lymphocyte-Activation Gene 3 (LAG-3) Overview

LAG-3, a member of the immunoglobulin superfamily (IgSF), plays a critical role in regulating immune responses. It associates with the CD3/T-cell receptor (TCR) complex and binds to MHC class II molecules, blocking their interaction with TCR and CD4, thereby directly inhibiting TCR signaling. Through this mechanism, LAG-3 delivers inhibitory signals that maintain immune cell homeostasis and modulate T cell activation, proliferation, cytokine secretion, and cytolytic activity.

Disruption of LAG-3-mediated immune regulation-such as in chronic autoimmune conditions-can lead to rapid and damaging immune responses. In the context of cancer and chronic viral infections, continuous antigen exposure results in sustained LAG-3 expression, contributing to T cell exhaustion and impaired immune function. To counter this, numerous LAG-3-targeted immunotherapies are currently in clinical development, often in combination with PD-1/PD-L1 inhibitors, aiming to restore immune activity and improve treatment outcomes in cancer.

LAG-3 is an immune checkpoint receptor (IR) expressed on activated and dysfunctional T cells, where it acts as a negative regulator of T cell function. As such, it has emerged as a promising therapeutic target for modulating T-cell responses across various diseases. This section explores research supporting the role of LAG-3 in regulating immune responses in autoimmunity, chronic infections (both viral and parasitic), and cancer. Although LAG-3 has been investigated in a range of disease models, most studies-particularly in preclinical and clinical settings-have focused on its role in cancer, reflecting the growing prominence of immunotherapy in oncology.

Lymphocyte-Activation Gene 3 (LAG-3) Epidemiology

The LAG-3 epidemiology chapter in the report provides historical as well as forecasted epidemiology segmented as total cases in selected indications for LAG-3, total eligible patient pool for LAG-3 in selected indications, total treated cases in selected indications for LAG-3 in the 7MM covering the United States, EU4 (Germany, France, Italy, and Spain), and the United Kingdom, and Japan from 2020 to 2034.

• Among lung cancer cases, NSCLC accounts for approximately 85% of all diagnoses. This distribution highlights that NSCLC is the more prevalent form of lung cancer.
• In 2024, the total incident cases of NSCLC in 7MM was ~537,680, out of which the contribution of the US was ~38%.
• The total incident cases of HNSCC in the 7MM were approximately 150,900 in 2024, which is expected to increase in the upcoming years.
• In 2024, an estimated 302,260 new cases of breast cancer were reported in the US.
• In 2024, the American Cancer Society estimates approximately 310,720 new cases of invasive breast cancer among women in the US. Of these, roughly 15-20% will be classified as TNBC.
• According to the American Cancer Society, about 104,960 new melanomas will be diagnosed (about 60,550 in men and 44,410 in women) in the US in 2025.
• Among the EU4 and the UK, Germany accounted for the highest number of cases of ulcerative colitis, followed by the UK and the lowest number of cases in the Italy in 2024.
• Japan accounted for nearly 328,520 diagnosed prevalent cases of ulcerative colitis in 2024.
• The US accounted for approximately 8,018,650 diagnosed prevalent cases of psoriasis in 2024.

Lymphocyte-Activation Gene 3 (LAG-3) Drug Chapters

The drug chapter segment of the LAG-3 reports encloses a detailed analysis of LAG-3 marketed drugs and mid and late-stage pipeline drugs. It also helps understand the LAG-3's 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

OPDUALAG (nivolumab + relatlimab): Bristol Myers Squibb and Ono Pharmaceutical

OPDUALAG (nivolumab and relatlimab-rmbw) is a first-in-class, fixed-dose, dual immunotherapy combination of the programmed death-1 (PD-1) inhibitor nivolumab and the LAG-3 blocking antibody relatlimab. The FDA approved OPDUALAG for the treatment of patients with unresectable or metastatic melanoma and the European Commission (EC) has approved the fixed-dose combination of OPDUALAG for the first-line treatment of advanced (unresectable or metastatic) melanoma in adults and adolescents 12 years of age and older with tumor cell PD-L1 expression < 1% in 2022.

In February 2025, Bristol Myers Squibb announced that the Phase III RELATIVITY-098 trial, which evaluated OPDUALAG as an adjuvant treatment for patients with fully resected stage III-IV melanoma, failed to meet its primary endpoint of improving recurrence-free survival (RFS). The safety results for OPDUALAG were consistent with the established safety profiles of nivolumab and relatlimab. The company anticipates additional registrational study readouts between 2025 and 2027.

Emerging Drugs

Eftilagimod Alpha (IMP321): Immutep

Eftilagimod Alpha is Immutep's proprietary soluble LAG-3 clinical stage candidate that is a first-in-class antigen-presenting cell (APC) activator for the treatment of cancer, capitalizing on LAG-3's unique characteristics to stimulate both innate and adaptive immunity. Through its high affinity for a subset of MHC II ligands, efti binds to and activates APCs (e.g. dendritic cells, monocytes) leading to the expansion and proliferation of CD8+ (cytotoxic) T cells, CD4+ (helper) T cells, dendritic cells, NK cells, and monocytes. It also upregulates the expression of key biological molecules like IFN-ƴ and CXCL10 that further boost the immune system's ability to fight cancer.

Eftilagimod Alpha is under evaluation for a variety of solid tumors including NSCLC, HNSCC, and HER2-neg/low metastatic breast cancer. Its favorable safety profile enables various combinations, including anti-PD-[L]1 immunotherapy and/or chemotherapy. Efti has received Fast Track Designation (FTD) in 1st line HNSCC and 1st line NSCLC from the US FDA.

In May 2025, Immutep announced that a 60.8% response rate and 90.2% disease control rate, according to RECIST1.1, had been achieved in the investigator-initiated INSIGHT-003 trial as of the data-cut-off date of 06 May 2025. INSIGHT-003 trial is evaluating eftilagimod alpha (efti) in combination with anti-PD-1 therapy, KEYTRUDA (pembrolizumab), and doublet chemotherapy as first-line treatment for patients with advanced or metastatic non-squamous NSCLC.

Fianlimab (REGN3767): Regeneron Pharmaceuticals

Fianlimab (REGN3767) is an investigational antibody targeting LAG-3 and is being evaluated across multiple clinical settings. Ongoing studies include Phase II/III trials in first-line advanced NSCLC, as well as trials in perioperative NSCLC and perioperative melanoma. In addition, fianlimab is being investigated for the treatment of first-line metastatic melanoma and as an adjuvant therapy for melanoma. These trials aim to explore the potential of fianlimab in combination with other agents to improve outcomes across various stages of cancer treatment.

Based on a pre-planned interim analysis of two Phase II/III studies in first-line advanced NSCLC, the Phase II portion of the studies will continue without modification. A Phase II study evaluating fianlimab in combination with LIBTAYO in first-line metastatic HNSCC is expected to begin in 2025. Additionally, results from the Phase III study comparing fianlimab plus cemiplimab to pembrolizumab in first-line metastatic melanoma are anticipated in the second half of 2025. Also, data from the Phase II/III studies in first-line advanced NSCLC are expected to be reported in the first quarter of 2026.

Drug Class Insights

LAG-3 represent a novel class of immune checkpoint therapies aimed at restoring T-cell function and enhancing anti-tumor immunity. They are typically used in combination with PD-1/PD-L1 inhibitors due to synergistic effects. The first approved therapy in this class, OPDUALAG (relatlimab + nivolumab), demonstrated efficacy in unresectable or metastatic melanoma. Other agents, such as fianlimab (REGN3767) from Regeneron, are in advanced clinical development for multiple cancers including NSCLC, melanoma, and HNSCC. LAG-3 have shown promising safety profiles and are being explored across first-line, adjuvant, and perioperative settings.

Lymphocyte-Activation Gene 3 (LAG-3) Market Outlook

The market for LAG-3 is expected to grow significantly in the coming years. This is due to the increasing number of patients who are being diagnosed with different types of cancers, the growing awareness of LAG-3, and the increasing number of LAG-3 that are under clinical trials and filed for approval by various companies.

OPDUALAG, the first approved LAG-3 combination (relatlimab + nivolumab), is used for treating unresectable or metastatic melanoma, offering a novel option beyond traditional PD-1 monotherapy. Several key players, including Immutep, Novartis, Regeneron Pharmaceuticals, Agenus, and others, are involved in developing drugs for LAG-3 for various indications such as NSCLC, breast cancer, and others. Overall, this is an exciting new class of agents with great potential for development. The maturation of current studies over the next few years will lead to a better understanding of LAG-3 and define their role in the therapy of cancer.

Lymphocyte-Activation Gene 3 (LAG-3) Drugs Uptake

This section focuses on the uptake rate of potential approved and emerging LAG-3 expected to be launched in the market during 2025-2034.

Lymphocyte-Activation Gene 3 (LAG-3) Pipeline Development Activities

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

The presence of numerous drugs under different stages is expected to generate immense opportunity for LAG-3 market growth over the forecasted period.

Pipeline Development Activities

The report covers information on collaborations, acquisitions and mergers, licensing, and patent details for LAG-3 therapies.

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 LAG-3 s' evolving treatment landscape, patient reliance on conventional therapies, patient therapy switching acceptability, drug uptake, along challenges related to accessibility.

DelveInsight's analysts connected with 10+ KOLs to gather insights; however, interviews were conducted with 5+ KOLs in the 7MM. Centers such as Baptist Health Medical Group and others.

Their opinion helps understand and validate current and emerging therapy treatment patterns or LAG-3 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. In the SWOT analysis, strengths, weaknesses, opportunities, and threats in terms of disease diagnosis, patient awareness, patient burden, competitive landscape, cost-effectiveness, and geographical accessibility of therapies are provided. These pointers are based on the analyst's discretion and assessment of the patient burden, cost analysis, and existing and evolving treatment landscape.

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.

The abstract list is not exhaustive, will be provided in the final report

Key Updates on LAG-3

• In May 2025, Immutep announced that an excellent median Overall Survival (OS) of 17.6 months had been achieved in Cohort B of the TACTI-003 (KEYNOTE-C34) Phase IIb trial. This part of the Phase II study evaluates eftilagimod alfa (efti) in combination with KEYTRUDA as first-line therapy in recurrent/metastatic HNSCC patients with PD-L1 expression below 1 (Combined Positive Score [CPS] <1).
• In March 2025, Immutep announced that the first patient had been successfully dosed in the Company's pivotal TACTI-004 Phase III trial. TACTI-004 will evaluate Immutep's eftilagimod alfa in combination with KEYTRUDA and chemotherapy as first-line treatment for patients with advanced or metastatic NSCLC.
• In March 2025, Immutep announced a poster presentation of the pivotal TACTI-004 Phase III trial, which will be presented at the European Lung Cancer Congress (ELCC) 2025.
• In December 2024, Merck announced the discontinuation of the clinical development programs for favezelimab, an anti-LAG-3 antibody. Favezelimab is being evaluated as an investigational fixed-dose combination with pembrolizumab in the KEYFORM program.

Scope of the Report:

• The report covers a segment of key events, an executive summary, and a descriptive overview of the LAG-3, explaining its mechanism, and therapies (current and emerging).
• 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 LAG-3 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 LAG-3 market.

LAG-3 Report Insights

• LAG-3 Targeted Patient Pool
• Therapeutic Approaches
• LAG-3 Pipeline Analysis
• LAG-3 Market Size and Trends
• Existing and future Market Opportunity

LAG-3 Report Key Strengths

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

LAG-3 Report Assessment

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

Key Questions:

• What was the LAG-3 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?
• What are the pricing variations among different geographies for approved therapies?
• How the reimbursement landscape has for LAG-3 evolved since the first one was approved? Do patients have any access issues that are driven by reimbursement decisions?
• What are the risks, burdens, and unmet needs of treatment with LAG-3? What will be the growth opportunities across the 7MM for the patient population of LAG-3?
• What are the key factors hampering the growth of the LAG-3 market?
• What are the indications for which recent novel therapies and technologies have been developed to overcome the limitations of existing treatments?
• What key designations have been granted to the therapies for LAG-3?
• What is the cost burden of approved therapies on the patient?
• Patient acceptability in terms of preferred therapy options as per real-world scenarios?
• What are the country-specific accessibility issues of expensive, recently approved therapies?

Reasons to buy:

• The report will help develop business strategies by understanding the latest trends and changing dynamics driving the LAG-3 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.