LYT-200

Metastatic/locally advanced solid tumors, including urothelial and head and neck cancers, and hematological malignancies, such as acute myeloid leukemia

< WHOLLY OWNED PIPELINE

Our programs ¹

Discovery

Preclinical

Phase 1

Phase 2

Phase 3

LYT-200

Anti-Galectin-9 mAb

Solid tumors and hematological malignancies

Phase:
1

Initial Indications:
Solid tumors

Patient Population:

~82K/year U.S. (Bladder cancer)
~66K/year U.S. (Head and neck cancers)
~20K/year U.S. (AML)

Key Differentiations:

Fully human IgG4 monoclonal antibody, or mAb, designed to inhibit the activity of galectin-9, an immunomodulatory molecule expressed by tumors and immune cells and shown to suppress the immune system from recognizing and destroying cancer cells. We are developing LYT-200 for the treatment of metastatic/locally advanced solid tumors that have poor survival rates, including urothelial and head and neck cancers. We are also developing LYT-200 for the treatment of hematological malignancies, such as acute myeloid leukemia (AML).

More about LYT-200

Phase completed

Phase in progress

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.

Metastatic/locally advanced solid tumors, including urothelial and head and neck cancers, and hematological malignancies, such as acute myeloid leukemia

LYT-200 is being developed for the treatment of metastatic/locally advanced solid tumors, including urothelial and head and neck cancers, as well as for the treatment of hematological malignancies, such as acute myeloid leukemia (AML). It is a fully human IgG4 monoclonal antibody designed to inhibit the activity of galectin-9, an immunomodulatory molecule expressed by tumors and immune cells and shown to suppress the immune system from recognizing and destroying cancer cells.

Key Points of Innovation & Differentiation
- Galectin-9 promotes and facilitates multiple immunosuppressive pathways by expanding regulatory T cells, shifting macrophages from the M1 to M2 phenotype, and inducing apoptosis of activated CD4+ and CD8+ T cells. High expression of galectin-9 is evident in solid tumors and in hematological malignancies, both in patients’ tumors and blood, and correlates with poor survival outcomes and aggressive disease. Our preclinical work demonstrates single agent mechanistic and anti-tumor efficacy of LYT- 200 in multiple animal and patient-derived tumor cell models. For example, LYT-200 outperforms anti-PD-1 in a standard B16F10 melanoma model as a single agent. LYT-200 also synergizes with anti-PD-1 in activating CD4 and CD8 T cells in melanoma and pancreatic in vivo models. We are advancing LYT-200 to inhibit the multiple effects of galectin-9 and thereby potentially removing a key immunosuppressive barrier that would enable the immune system to attack and destroy the tumor.
- A 2021 study published in Nature Communications proposed that the molecular mechanism by which PD-1 and galectin-9 interact to shield tumors from the immune system demonstrates for the first time that galectin-9 is a ligand for PD-1 and emphasizes its importance as a promising target for immunotherapy³. This provided further evidence that galectin-9 acts as a key regulator of the immune response to tumors and supports its importance as a potential target for cancer treatment.
- We believe that LYT-200 is the most advanced clinical program against this target. It has the potential to be used as a single agent and safely in combination with checkpoint inhibitors and other anti-cancer therapies, depending on the cancer type, treatment setting and line of treatment. Additionally, targeting galectin-9 gives LYT-200 the potential to address a high unmet need for more effective therapies with improved tolerability for acute myeloid leukemia (AML), a devastating disease in which prognosis is poor.
Program Discovery Process by the PureTech Team
- In order to identify approaches with the potential to provide significant therapeutic benefit to cancer patients, we opportunistically identified a foundational immunosuppressive mechanism involving galectin-9, which was the basis of certain intellectual property that we licensed from New York University prior to its publication in Nature Medicine.
Patient Need & Market Potential
- Metastatic/locally advanced solid tumors
  - In the US, there are approximately 82,000 new cases of bladder cancer each year³ of which ~90% are urothelial carcinoma.⁴ While metastatic disease only accounts for ~5% of bladder cancer diagnoses, prognosis for these patients is extremely poor with a 5-year survival rate of ~5%.⁴
  - In the US, there are approximately 66,000 people diagnosed with head and neck cancers each year.⁵ At diagnosis, ~10% of patients have metastatic disease though an additional 20-30% will develop metastases during the course of their disease. The prognosis for metastatic disease is unfavorable with a median survival of about 10 months.⁶
- AML
  - The National Cancer Institute estimates that about 60,000 new cases of leukemia are diagnosed each year,⁷ including about 20,000 in AML.⁸ More than 50% of AML patients either don’t respond to initial treatment or experience relapse or death after responding to initial treatment¹ and have an approximately 12.6% five-year survival rate.² The poor overall survival highlights the need for more effective therapies for patients with relapsed and refractory AML.
Milestones Achieved & Development Status
- AML
  - In December 2022, a poster describing new preclinical data supporting the clinical potential of LYT-200 for the treatment of leukemia was presented at the American Society of Hematology (ASH) 64th Annual Meeting. In all models used, LYT-200 demonstrated significant anti-tumor activity and in addition to its established effects on the immune system in solid tumor models, it also notably induced direct apoptosis or cell death across all leukemia cell types. Based on this and other compelling preclinical data generated with LYT-200 in blood cancers, we initiated a clinical trial to evaluate LYT-200 as a single agent for the treatment of AML.
- Metastatic/locally advanced solid tumors
  - In December 2022, we announced results from the monotherapy dose escalation portion of the Phase 1 program of LYT-200 as a potential treatment for metastatic solid tumors. No dose-limiting toxicities were reported, and the full results are planned for presentation in a scientific forum in 2023.
  - In the first quarter of 2023, we initiated a Phase 1b trial of LYT-200 in combination with tislelizumab in urothelial and head and neck cancers.
Expected Milestones
- Initial results from a subset of patients from the Phase 1b clinical trial to evaluate LYT-200 as a single agent for the treatment of AML are expected by the end of 2023.
- Topline results from the Phase 1b trial of LYT-200 in combination with tislelizumab in urothelial or head and neck cancers are expected in 2024.
Intellectual Property
- We have broad intellectual property coverage for these antibody-based immunotherapy technologies, including exclusive rights to seven families of patent filings that are exclusively licensed from or co-owned with New York University which cover antibodies that target galectin-9, including LYT-200, methods of using these antibodies, and related immuno-oncology technologies. In addition, the intellectual property portfolio includes ten families of PureTech-owned patent applications covering the use of antigalectin-9 antibodies in the diagnosis and treatment of solid tumors.
- As of December 31, 2022, there are 17 families of intellectual property within this patent portfolio covering compositions of matter for antibodies targeting galectin-9, including LYT-200, and methods of use for the treatment of solid tumors and various other cancers, and methods of use for the treatment of hematological cancers. This intellectual property comprises three issued US patents which are expected to expire in 2038, 15 pending US patent applications, which if issued, are expected to expire 2037 through 2043, six international PCT applications, 34 pending foreign applications and eight issued patents in foreign jurisdictions.

¹ Walter, R. B., Othus, M., Burnett, A. K., Löwenberg, B., Kantarjian, H. M., Ossenkoppele, G. J., Hills, R. K., Ravandi, F., Pabst, T., Evans, A., Pierce, S., Vekemans, M.,
Appelbaum, F. R., & Estey, E. H. (2015). Resistance prediction in AML: analysis of 4601 patients from MRC/NCRI, HOVON/SAKK, SWOG and MD Anderson Cancer Center.
Leukemia, 29(2), 312–320. https://doi.org/10.1038/leu.2014.242

² Brandwein, J., Saini, L. M., Geddes, M., Yusuf, D., Liu, F., Schwann, K., Billawala, A., Westcott, C., Kurniawan, J. A., & Cheung, W. Y. (2020). Outcomes of patients with
relapsed or refractory acute myeloid leukemia: a population-based real-world study. American Journal of Blood Research, 10(4), 124–133.

³ Cancer of the Urinary Bladder – Cancer Stat Facts. (n.d.). National Cancer Institute. https://seer.cancer.gov/statfacts/html/urinb.html

⁴ Saginala, K., Barsouk, A., Aluru, J. S., Rawla, P., Padala, S. A., & Barsouk, A. (2020). Epidemiology of Bladder Cancer. Medical Sciences, 8(1), 15. https://doi.org/10.3390/
medsci8010015

⁵ Head and Neck Cancer – Statistics. (2022, December 16). Cancer.Net. https://www.cancer.net/cancer-types/head-and-neck-cancer/statistics

⁶ Pisani, P., Airoldi, M., Allais, A., Valletti, P. A., Battista, M., Benazzo, M., Briatore, R., Cacciola, S., Cocuzza, S., Colombo, A., Conti, B., Costanzo, A., Della Vecchia, L., Russi,
E. G., Fantozzi, C., Galizia, D., Garzaro, M., Genta, I., Iasi, G. A., . . . Zigliani, A. (2020). Metastatic disease in head & neck oncology. Acta Otorhinolaryngologica Italica,
40(SUPPL. 1), S1–S86. https://doi.org/10.14639/0392-100x-suppl.1-40-2020

⁷ Leukemia – Cancer Stat Facts. (n.d.). National Cancer Institute. https://seer.cancer.gov/statfacts/html/leuks.html

⁸ Acute Myeloid Leukemia – Cancer Stat Facts. (n.d.). National Cancer Institute. https://seer.cancer.gov/statfacts/html/amyl.html

Given its design to inhibit the activity of galectin-9, LYT-200 is being advanced to potentially remove a key immunosuppressive barrier that would enable the immune system to attack and destroy the tumor. Our fully human monoclonal antibody candidate has potential both as a single agent and in combination with existing therapies such as checkpoint inhibitors and chemotherapeutics.