Phase 1 Clinical Trial of Personal Neoantigen-Targeted T Cell Therapy Expected to Initiate in Third Quarter 2020

CAMBRIDGE, MA, USA I April 30, 2020 I Neon Therapeutics, Inc. (Nasdaq: NTGN) today announced the acceptance of its Clinical Trial Authorization (CTA) from the Dutch Health Authority (DHA) for its personal neoantigen-targeted T cell therapy candidate, NEO-PTC-01. Neon’s initial Phase 1 clinical trial of NEO-PTC-01 will be in patients with metastatic melanoma who are not responsive to checkpoint inhibitors.  NEO-PTC-01 is a personal neoantigen-targeted T cell therapy candidate derived from patients’ peripheral blood mononuclear cells (PBMCs) and consisting of multiple T cell populations targeting the most therapeutically relevant neoantigens from each patient’s tumor.

The Phase 1 dose-finding clinical trial in metastatic melanoma will be conducted in collaboration with the Netherlands Cancer Institute and is expected to begin in the third quarter of 2020, subject to the ability to commence that trial in the Netherlands in light of the current COVID-19 outbreak. Neon is also planning for a second indication for NEO-PTC-01 in metastatic ovarian cancer, as well as for the potential to both expand to other solid tumor types and pursue clinical development in the United States.

“We are excited to be able to initiate this first-in-human study of NEO-PTC-01 as it brings us closer to demonstrating NEO-PTC-01’s potential to prime, activate and expand neoantigen-targeting T cells in solid tumors. Importantly, moving forward with this important trial advances our goal to shift the paradigm in the treatment of cancer patients towards an era of truly personal immuno-oncology therapies,” said Hugh O’Dowd, Chief Executive Officer of Neon.

“We believe that NEO-PTC-01 has several key advantages that overcome the challenges of other cell therapy approaches. In preclinical studies, including research using patient tumor samples, we have demonstrated the ability to produce multiple neoantigen-specific CD8and CD4+ T cell populations, including both memory and de novo T cell responses. We have further shown that these T cell populations kill tumor cells by targeting tumor neoantigens,” said Richard Gaynor, M.D., President of Research and Development at Neon. “We believe that our approach to leveraging these neoantigen targets will provide the tumor specificity required to develop safe, effective and durable T cell therapies for the treatment of solid tumors. We look forward to demonstrating these potential benefits in our Phase 1 study in checkpoint inhibitor, non-responsive metastatic melanoma, which will commence later this year.”

About Neon Therapeutics

Neon is a biotechnology company developing novel neoantigen-targeted T cell therapies, dedicated to transforming the treatment of cancer by directing the immune system towards neoantigens. Neon is using its neoantigen platform to develop both personal and precision neoantigen-targeted T cell therapy candidates. Neon’s most advanced program is NEO-PTC-01, its personalized neoantigen-targeted T cell therapy candidate consisting of multiple T cell populations targeting the most therapeutically relevant neoantigens from each patient’s tumor.

For more information, please visit www.neontherapeutics.com.

SOURCE: Neon Therapeutics