LYT-200

Targeting galectin-9 to unlock new possibilities in cancer treatment

Description

Myeloid malignancies, such as relapsed/refractory (R/R) high-risk (HR) myelodysplastic syndrome (MDS) and R/R acute myeloid leukemia (AML)

PURETECH ECONOMIC INTEREST¹

100% Equity

Stage of Development

Phase 1/2

¹ We have an active IND on file with the FDA for LYT-200. The FDA and corresponding regulatory authorities will ultimately review our clinical results and determine whether our wholly-owned therapeutic candidates are safe and effective. No regulatory agency has made any such determination that LYT-200 is safe or effective for use by the general public for any indication.

Myeloid malignancies, such as relapsed/refractory (R/R) high-risk (HR) myelodysplastic syndrome and R/R acute myeloid leukemia (AML)

Gallop Oncology (Gallop) is a clinical-stage biopharmaceutical company committed to transforming treatment paradigms for myeloid malignancies. To the company’s knowledge, its lead candidate, LYT-200, is the most advanced therapeutic targeting galectin-9, an important oncogenic driver and potent immunosuppressor, offering a differentiated strategy to address some of the most challenging cancers. LYT-200 has generated compelling clinical efficacy data while maintaining favorable tolerability in both relapsed/refractory (R/R) high-risk (HR) myelodysplastic syndrome (MDS) and R/R acute myeloid leukemia (AML).

Patient Need & Market Potential
R/R HR-MDS
- Myelodysplastic syndromes are a group of serious blood cancers in which the bone marrow does not produce enough healthy blood cells.^1,2 This can lead to anemia, infections, and bleeding complications.^1,2 MDS affects approximately 60,000–170,000 people in the U.S., with approximately 30–40% of patients diagnosed with the more aggressive form of the disease known as HR-MDS.^1,3 HR-MDS is associated with poor outcomes, with patients typically surviving less than two years after diagnosis.^3,4 Additionally, approximately 30% of patients with HR-MDS progress to AML.^2,3
- The current standard frontline treatments for HR-MDS are hypomethylating agents (HMA), such as azacitidine and decitabine. However, most patients do not respond to these therapies or eventually stop benefiting from them.^1,5 Once the disease becomes R/R, meaning it returns or does not respond to treatment in the first place, outcomes are especially poor, with patients often surviving only a few months.^5,6
- Treatment options for patients with R/R HR-MDS are very limited, and there has been only one new therapy approved specifically for this setting in the past two decades, and it targets only a small subset of patients (~3–5%) with a specific genetic mutation.⁵ As a result, there remains a significant need for new treatment approaches that can improve outcomes for these patients.
R/R AML
- AML is an aggressive blood cancer characterized by the rapid growth of abnormal myeloid blast cells in the bone marrow and blood. It is the most common form of acute leukemia in adults, with a five-year survival rate of less than 30%. Despite available therapies, many patients relapse or fail to respond, and outcomes are especially poor in the R/R setting. Around 450,000 people globally are living with AML.⁷
  AML is an area of urgent medical need where new therapies with improved safety, efficacy, and durability of responses are critical. Importantly, the incidence of AML is increasing, and the market is expected to grow to $6 billion annually by 2030,⁸ underscoring the scale of the opportunity to bring forward therapies that are not only more effective but also applicable across a broader segment of patients.
Early Development & PureTech Innovation
- PureTech invented LYT-200 in conjunction with partners at New York University. The program began in 2017 after PureTech leveraged its industry-leading network of scientists and became aware of foundational insights around targeting galectin-9 before its publication in Nature Medicine. Galectin-9 promotes multiple immunosuppressive pathways, and blocking galectin-9 results in tumor cell death as well as induction of anti-tumor immunity in the context of hematological malignancies. High levels of galectin-9 expression in tumor tissue, on leukemia cells as well as in patients’ blood are generally linked to more advanced disease and worse outcomes.
- LYT-200 is a fully human IgG4 monoclonal antibody and, to our knowledge, the most advanced clinical program targeting galectin-9. Galectin-9 inhibition provides a dual mechanism of action: directly killing cancer cells, while also restoring anti-tumor immune function. This mutation-agnostic approach supports potential use of LYT-200 as both a monotherapy and in combination with other anti-cancer therapies, depending on the cancer type, treatment setting, and line of treatment. By addressing both tumor-intrinsic and immune-mediated pathways, Gallop’s strategy is differentiated from existing therapies and is designed to drive meaningful responses and improve clinical outcomes while maintaining safety.
Milestones Achieved & Development Status
- In April 2026, PureTech announced positive topline data from the completed Phase 1b clinical trial of LYT-200, which evaluated LYT-200 both as a monotherapy and in combination regimens in two heavily pretreated patient populations. The study included dose escalation of monotherapy LYT-200, followed by dose escalation of LYT-200 in combination with an HMA (azacitidine or decitabine) in patients with R/R HR-MDS and with venetoclax (VEN) and an HMA in R/R AML. This announcement followed the initial topline results that were announced in December 2025 and presented at the American Society of Hematology Annual Meeting. Based on these results, Gallop has selected a recommended Phase 2 dose and intends to engage with the FDA to discuss the design of a subsequent trial that could potentially support registration of LYT-200 in R/R HR-MDS.
  - Topline safety: LYT-200 demonstrated a favorable and consistent safety profile across all cohorts and dose levels studied (N=101), with no dose-limiting toxicities, infusion-related reactions, LYT-200 dose reductions, or LYT-200-related serious adverse events (AEs), discontinuations, or deaths. Importantly, no overlapping or additive toxicities were observed when LYT-200 was combined with an HMA or VEN/HMA.
  - Topline efficacy: Treatment with LYT-200 in combination with an HMA in R/R HR-MDS patients and VEN/HMA in R/R AML patients demonstrated robust antileukemic activity, including complete responses, bridging to transplant, and durable clinical benefit. The data also provided important insights into the contribution of LYT-200 within combination regimens.
    R/R HR-MDS
    Across all efficacy-evaluable⁹ patients (n=11), the recommended Phase 2 dose (LYT-200 12mg/kg in combination with an HMA) demonstrated:
    - 27.3% complete response rate
      
      9.1% partial response rate
      
      9.1% marrow complete response rate
      
      45.5% overall response rate
      
      18% conversion to transplant rate
    Due to the number of patients alive at the time of study completion (>50%), the upper bound of overall survival could not be calculated; therefore, the median overall survival for this cohort of 6.4 months is not considered fully mature.
    Efficacy-evaluable patients had a median of 3 prior lines of therapy (range: 1-5), and all (100%) had previously been treated with an HMA. Additionally, all patients had high-risk cytogenetics, which – coupled with prior exposure to treatment – suggests biologically aggressive, treatment-refractory disease with elevated risk of progression and poor clinical outcomes. Taken together, these attributes underscore the potential mutation-agnostic mechanism of LYT-200 and its potential for broad clinical use.
    
    R/R AML
    Across all efficacy-evaluable9 patients (n=26), LYT-200 12mg/kg in combination with VEN/HMA demonstrated:
    - 30.8% composite complete response rate¹⁰; responders included patients with mutations associated with VEN resistance
      
      7.7% partial response rate
      
      42.3% overall response rate
      
      19.2% conversion to transplant rate
    Due to the number of patients alive at the time of study completion (50%), the upper bound of overall survival could not be calculated; therefore, the median overall survival for this cohort of 8.2 months is not considered fully mature.
    Efficacy-evaluable patients had a median of 2 prior lines of therapy (range: 1-9), and 84.6% had previously been treated with VEN/HMA.
    - In January 2025, the FDA granted Fast Track Designation to LYT-200 for the treatment of AML. Fast Track Designation is a process designed to streamline the development and accelerate the assessment of drugs that target serious conditions with unmet medical need. LYT-200 was also granted Orphan Drug Designation in 2024, which allows for incentives under the Orphan Drug Act, including tax credits for some clinical trials and eligibility for seven years of market exclusivity in the U.S., if the drug is approved for AML.
Expected Milestones
- Gallop has selected a recommended Phase 2 dose and intends to engage with the U.S. FDA to discuss the design of a subsequent trial that could potentially support registration of LYT-200 in R/R HR-MDS.
- Gallop intends to pursue third-party capital to support a potentially registration-enabling trial in R/R HR-MDS, with the round targeted to close in the first quarter of 2027.
Intellectual Property
- The intellectual property portfolio for LYT-200 provides broad intellectual property coverage for antibody-based immunotherapy technologies. As of December 31, 2025, there are 15 families of intellectual property within this patent portfolio, including eight (8) families of patent filings that are co-owned with and/or exclusively licensed from New York University which cover antibodies that target galectin-9, including LYT-200, and methods of using these antibodies in various immuno-oncology technologies and other therapeutic methods. In addition, the intellectual property portfolio includes six (6) families of company-owned patent applications covering the use of anti-galectin-9 antibodies in the diagnosis and treatment of various cancers, including solid tumors and hematological cancers, and one family of patent applications co-owned with BeiGene directed to combination therapies for the treatment of solid tumors. This intellectual property portfolio comprises five (5) issued U.S. patents which are expected to expire in 2038, 12 pending U.S. patent applications, which if issued, are expected to expire 2037 through 2046, two (2) international PCT applications, 76 pending foreign applications and 41 issued patents in foreign jurisdictions.

LYT-200 is an investigational drug not approved by any regulatory authority.

¹ American Cancer Society. (2023). What Is Myelodysplastic Syndrome? Retrieved from https://www.cancer.org
² National Comprehensive Cancer Network. (2024). NCCN Clinical Practice Guidelines in Oncology: Myelodysplastic Syndromes (Version 2.2024). Retrieved from https://www.nccn.org
³ Greenberg, P. L., Tuechler, H., Schanz, J., Sanz, G., Garcia-Manero, G., Solé, F., Bennett, J. M., Bowen, D., Fenaux, P., Dreyfus, F., Kantarjian, H., Kuendgen, A., Levis, A., Malcovati, L., Cazzola, M., & Haase, D. (2012). Revised International Prognostic Scoring System for myelodysplastic syndromes. Blood, 120(12), 2454–2465. https://doi.org/10.1182/blood-2012-03-420489
⁴ Ma, X. (2012). Epidemiology of myelodysplastic syndromes. The American Journal of Medicine, 125(7 Suppl), S2–S5. https://doi.org/10.1016/j.amjmed.2012.04.014
⁵ Garcia-Manero, G., Fenaux, P., Al-Kali, A., Baer, M. R., Sekeres, M. A., Roboz, G. J., et al. (2016). Rigosertib versus best supportive care for patients with high-risk myelodysplastic syndromes after failure of hypomethylating drugs (ONTIME): A randomised, controlled, phase 3 trial. Lancet Oncology, 17(4), 496–508. https://doi.org/10.1016/S1470-2045(16)00009-7
⁶ Prébet, T., Gore, S. D., Esterni, B., Gardin, C., Itzykson, R., Thepot, S., Quesnel, B., Dreyfus, F., Beyne-Rauzy, O., Vey, N., Recher, C., Adès, L., Fenaux, P., & Groupe Francophone des Myélodysplasies. (2011). Outcome of patients with higher-risk myelodysplastic syndromes after azacitidine treatment failure. Journal of Clinical Oncology, 29(24), 3322–3327. https://doi.org/10.1200/JCO.2011.35.8135
⁷ Acute Myeloid Leukemia – Cancer Stat Facts. (n.d.). National Cancer Institute
⁸ Grand View Research, Acute Myeloid Leukemia Treatment Market Size, Share & Trends Analysis Report By Disease, By Treatment (Chemotherapy, Targeted Therapy, Immunotherapy), By Route of Administration, By End Use, By Region, And Segment Forecasts, 2025 Ð 2030
⁹ Efficacy evaluable is defined in the protocol as all patients who received a minimum one full cycle of LYT-200 (four doses) and had a minimum of one on-study disease assessment. The intent-to-treat population for the R/R HR-MDS cohort was n=12 and for the R/R AML cohort was n=33.
¹⁰ Complete response + complete response with incomplete hematological recovery

LYT-200 is a fully human IgG4 monoclonal antibody and, to our knowledge, the most advanced clinical program targeting galectin-9. Galectin-9 inhibition provides a dual mechanism of action: directly killing cancer cells, while also restoring anti-tumor immune function. This mutation-agnostic approach supports potential use of LYT-200 as both a monotherapy and in combination with other anti-cancer therapies, depending on the cancer type, treatment setting, and line of treatment. By addressing both tumor-intrinsic and immune-mediated pathways, Gallop’s strategy is differentiated from existing therapies and is designed to drive meaningful responses and improve clinical outcomes while maintaining safety.