PureTech Health plc (Nasdaq: PRTC, LSE: PRTC), a clinical-stage biotherapeutics company, has announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to LYT-200, a first-in-class anti-galectin-9 monoclonal antibody, for the treatment of acute myeloid leukemia (AML). This designation is a significant regulatory milestone that can accelerate the development and approval process for LYT-200, potentially bringing a much-needed therapeutic option to AML patients more quickly.

AML is a devastating disease with a poor prognosis, affecting approximately 20,000 new patients each year in the United States alone. More than 50% of AML patients either don't respond to initial treatment or experience relapse or death after responding to initial treatment, with a median survival time of less than six months. The poor overall survival rate highlights the urgent need for more effective therapies with improved tolerability.

LYT-200 is a fully human IgG4 monoclonal antibody targeting galectin-9, a potent oncogenic driver in leukemia cells and an immunosuppressive protein expressed by tumors and immune cells. Galectin-9 has been shown to suppress the immune system's ability to recognize and destroy cancer cells, making it an attractive target for cancer therapy. Preclinical data support the potential clinical efficacy of LYT-200 and the importance of galectin-9 as a target, suggesting a potential opportunity for biomarker development.



LYT-200's dual mechanism of action – direct cancer cell killing via apoptosis and DNA damage, as well as reactivation of central anti-cancer effectors of the immune system – positions it as a potentially versatile therapeutic option. Early clinical data from a Phase 1b trial presented at the 2024 American Society of Hematology (ASH) Annual Meeting showed that LYT-200 has the potential to serve a broad range of patients across various lines of treatment, including those with complex cytogenetics, mutations, and even patients previously fully refractory to standard of care. In the monotherapy arm, 59% of evaluable patients achieved stable disease or better, with two partial responses. In the combination arm with venetoclax and hypomethylating agents, 80% of evaluable patients achieved stable disease or better, including two complete responses and one patient achieving a morphologic leukemia free state (MLFS).

The FDA's Fast Track designation for LYT-200 in AML reflects the agency's recognition of both the unmet medical need and the promising preliminary data. This designation provides several key advantages, including more frequent FDA interactions for rapid issue resolution, rolling review eligibility for the future New Drug Application (NDA) submission, and potential qualification for Accelerated Approval and Priority Review. These advantages can help PureTech advance LYT-200 through the regulatory pathway more efficiently.

PureTech previously announced that it intends to advance LYT-200 via its Founded Entity, Gallop Oncology. The planned advancement of LYT-200 through Gallop Oncology suggests a potential spin-off strategy that could unlock additional shareholder value for PureTech. The dual-pronged clinical development in both hematological and solid tumors expands market opportunity while diversifying risk. The partnership with BeiGene for combination studies adds credibility and reduces development costs. Early signals of clinical activity across multiple indications could attract potential licensing deals or strategic partnerships, providing additional non-dilutive funding options.

In conclusion, PureTech's LYT-200 has received FDA Fast Track designation for AML treatment, reflecting the agency's recognition of the unmet medical need and the promising preliminary data. With its dual mechanism of action and potential for broad patient applicability, LYT-200 has the potential to become a critical therapeutic option for AML patients. The Fast Track designation can accelerate the development and approval process, bringing a much-needed therapeutic option to patients more quickly.