1ST Biotherapeutics Announces Clinical Trial Collaboration and Supply Agreement with MSD to Evaluate FB849 in Combination With KEYTRUDA® (pembrolizumab)


1ST Biotherapeutics, Inc., a clinical-stage biotechnology company focused on the development of novel small molecule therapeutics in neurodegenerative diseases, immuno-oncology, and rare diseases, today announced a Clinical Trial Collaboration and Supply Agreement (CTCSA) with MSD, a tradename of Merck & Co., Inc., Rahway, NJ, USA, to evaluate FB849 in combination with MSD’s anti-PD-1 therapy KEYTRUDA® (pembrolizumab) in a Phase I/II clinical trial for the treatment of patients with advanced solid tumors.

Under the terms of the agreement, MSD will provide KEYTRUDA to be used in combination with FB849 for the planned Phase I/II study.

“We are very pleased to mark the next stage of FB849’s development with this exciting collaboration. We are hopeful that combining FB849 with KEYTRUDA may induce an effective anti-tumor response and show an additive benefit for patients with advanced solid tumors,” said Jamie Jae Eun Kim, Ph.D., Founder and Chief Executive Officer of 1ST Biotherapeutics. “This collaboration will play an important role in the advancement of this program and marks further validation of our differentiated drug discovery and development approach. We will continue to leverage our expertise and dedication to bring innovative therapeutics to patients with high unmet medical needs.”

The Phase I/II study (NCT05761223) is a first-in-human, multicenter, open-label study to assess the safety, tolerability, pharmacokinetics, and preliminary efficacy of FB849 alone as a monotherapy and in combination with KEYTRUDA for the treatment of advanced solid tumors. The recruitment in the clinical study is expected in the second half of 2023.

KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.



About FB849

FB849 is a 1ST Biotherapeutic’s proprietary small molecule inhibitor of hematopoietic progenitor kinase 1 (HPK1) as a novel next-generation immuno-oncology agent. Throughout the preclinical studies, it has been demonstrated that FB849’s highly selective inhibition of HPK1 induces potent anti-cancer immunity via cross-spectrum immune cell invigoration, including T cells, B cells, dendritic cells, and macrophages, with robust and durable effects in tumor growth inhibition. 

About 1ST Biotherapeutics

1ST Biotherapeutics is a science-driven biopharmaceutical company focused on the development of breakthrough therapies in neurodegenerative diseases, immuno-oncology, and rare diseases. Founded in 2016, 1ST Biotherapeutics has rapidly developed a deep pipeline of first-in-class investigational therapeutics with clear mechanisms for proper disease modification and excellent pharmacological properties. 1ST Biotherapeutics is based in Yongin, South Korea.