Gallop Oncology's LYT-200 Shows Promising 13.2-Month Survival in Relapsed/Refractory AML Phase 1b Trial
核心洞察
Gallop Oncology (搜索)'s first-in-class anti-galectin-9 (搜索) monoclonal antibody LYT-200 demonstrated initial median overall survival of 13.2 months in combination therapy, significantly exceeding the typical <2.5 months expected in relapsed/refractory AML patients.
The Phase 1b trial showed favorable safety with no LYT-200-related serious adverse events and achieved a 38% complete response rate at the proposed Phase 2 dose of 12 mg/kg in heavily pretreated patients.
LYT-200 showed activity across diverse high-risk mutations including KRAS (搜索), NRAS (搜索), JAK2 (搜索), and KIT (搜索), supporting its mutation-agnostic mechanism and potential broad applicability in AML treatment.
Gallop Oncology (搜索) announced positive initial topline results from its Phase 1b clinical trial evaluating LYT-200, a first-in-class anti-galectin-9 (搜索) monoclonal antibody, in patients with relapsed/refractory acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS). The data demonstrated favorable tolerability and strong efficacy, supporting advancement into a potentially registrational Phase 2 trial in AML.
The most striking finding was an initial median overall survival of 13.2 months observed in the combination cohort at the proposed Phase 2 dose, dramatically exceeding the expected survival of less than 2.5 months typically seen in late-line relapsed/refractory AML patients. Overall survival data at this dose continue to mature, with final results expected in the first half of 2026.
Trial Design and Patient Population
The Phase 1b, open-label, dose-escalation and dose-expansion trial evaluated LYT-200 both in combination with the standard-of-care regimen of venetoclax and a hypomethylating agent, and as monotherapy in a heavily pretreated patient population. The median number of prior lines of treatment was 3, with a range of 1-7 previous therapies.
Notably, 87.5% of participants in the combination cohort had previously been treated with venetoclax and hypomethylating agents, and their disease had either returned or failed to respond to this standard treatment.
Safety Profile
LYT-200 demonstrated a favorable safety profile across 101 patients, with no LYT-200-related serious adverse events or dose-limiting toxicities observed. Importantly, no overlapping or additive toxicities were seen when LYT-200 was combined with venetoclax and hypomethylating agents.
Efficacy Results
Combination Therapy
Across all evaluable patients treated with LYT-200 in combination with venetoclax and hypomethylating agents (n=43), robust antileukemic activity was demonstrated, with a combined complete response rate of 33%. Among those who achieved a complete response, 50% proceeded to stem cell transplant.
At the proposed Phase 2 dose of 12 mg/kg (n=32 evaluable), treatment with LYT-200 in combination demonstrated:
- 38% combined complete response rate
- 97% disease control rate
- Initial median overall survival of 13.2 months
Monotherapy Results
As monotherapy (n=26 evaluable), LYT-200 demonstrated clinical activity and disease stabilization in patients whose disease had progressed following multiple prior lines of treatment. Median overall survival in this cohort was 6.5 months, and one partial response has been maintained for 27 months in a patient whose disease previously progressed following five prior rounds of treatment.
Broad Applicability Across High-Risk Mutations
Responses were observed in patients with diverse, high-risk mutations, including KRAS (搜索), NRAS (搜索), JAK2 (搜索), and KIT (搜索), underscoring LYT-200's mutation-agnostic mechanism of action and potential for broad use across different patient populations.
"LYT-200 is not a targeted therapy in the traditional sense; it targets galectin-9 (搜索), a foundational driver of leukemia biology," said Amir T. Fathi, MD, Program Director of the Center for Leukemia at the Massachusetts General Hospital Cancer Center and Associate Professor of Medicine at Harvard Medical School. "The significance of this approach is evidenced by the activity observed across multiple high-risk mutations, suggesting LYT-200 may be uniquely applicable across a broad patient population."
Regulatory Status and Next Steps
LYT-200 has been granted Fast Track and Orphan Drug designations from the U.S. Food and Drug Administration for the treatment of AML. Gallop intends to engage with regulatory authorities to discuss the proposed Phase 2 dose and potentially registrational path after the overall survival data have fully matured.
"The strength of the data gives us confidence as we advance toward a potentially registrational Phase 2 study in AML and supports future evaluation of LYT-200 in earlier lines of treatment," said Luba Greenwood, JD, Chief Executive Officer of Gallop Oncology (搜索).
Mechanism of Action
LYT-200 is a fully human IgG4 monoclonal antibody targeting galectin-9 (搜索), a key oncogenic driver and potent immunosuppressor in cancer. Blocking galectin-9 is believed to have a dual mode of action, both killing tumor cells directly while also stimulating anti-tumor immunity. Galectin-9 is considered the fundamental driver of the AML disease process, with AML stem cells showing higher expression of galectin-9 than their healthy counterparts, and higher expression being associated with treatment failure.
Disease Context
Acute myeloid leukemia is an aggressive blood cancer characterized by the rapid growth of abnormal myeloid 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 relapsed/refractory setting. Around 450,000 people globally are living with AML, and the market is expected to grow to $6 billion by 2030.
Additional details from the trial will be shared at the 67th American Society of Hematology Annual Meeting on December 6th, 2025.