Forlong Biotechnology Receives Milestone Payment as Partner Submits IND for A Protein Therapy using its Proprietary Fbody® Technology

SHANGHAI & SUZHOU, China--(BUSINESS WIRE)--Forlong Biotechnology, a clinical-stage biotech company focusing on developing transformative cytokine therapies for patients with severe unmet needs, today announced that it has received the first milestone payment under its licensing and collaboration agreements with Shell BioTech and a third party.

In 2020 Forlong and Shell BioTech, a CDMO in China, entered a technology development collaboration to leverage Forlong’s proprietary Fbody^® Technology Platform to develop long half-life peptide therapy for a third party. In 2025, Forlong and Shell BioTech entered into a licensing agreement with the third party for selected protein therapy candidates incorporating Fbody^®, and amended the initial collaboration agreement to restructure terms including upfront and milestones payments as well as royalty on future product sales. Following the upfront payment in 2025, this is the first milestone payment, triggered by IND submission for the Fbody^®-fusion protein therapy by the third party to China National Medical Products Administration.

Fbody^® Long-acting Technology is one of synthetic immunology platforms of Forlong. It is a single-chain Fc engineered to maintain FcRn affinity while eliminating binding of FcγRs and complement systems, aiming to optimize protein half-life and biodistribution. Forlong’s lead clinical candidate FL115 is an interleukin-15 (IL-15) superagonist incorporating Fbody^®. It is in multiple clinical studies in China and the United States, showing favorable safety profile and preliminary clinical responses in patients with advanced solid tumors, and is currently being advanced to combo therapy with PD-(L)1 antibodies in Phase I for patients with advanced solid tumors and combo therapy with Bacillus Calmette-Guérin (BCG) in Phase II for patients with nonmuscle invasive bladder cancer (NMIBC).

"We are excited to see another Fbody^® fusion protein therapy advancing into clinic, a significant milestone for our synthetic immunology platforms,” said Dong Wei, Ph.D., Chief Executive Officer of Forlong Biotechnology, “FL115’s best-in-class potential in the challenging IL-15 superagonist class first showcased unique properties of Fbody^®, and this milestone further validates its ability to enhance profiles for variety of proteins beyond cytokines, and success of our out-licensing strategy and its ability to drive real-world impact through partnerships."

About Forlong Biotechnology

Forlong Biotechnology is a clinical-stage biotech company focusing on developing transformative cytokine therapies for patients with severe unmet needs. It has established four proprietary synthetic immunology platforms: Fbody^® Long-acting Technology Platform, Fc engineering platform, Syntokine^® Synthetic Cytokine Platform and AI-driven Intelligent Biomolecular Discovery Platform. Its lead candidate FL115 is interleukin-15 (IL-15) superagonist with best-in-class potential, currently being advanced to combo therapy with PD-(L)1 antibodies in Phase I for patients with solid tumors and combo therapy with Bacillus Calmette-Guérin (BCG) in Phase II for patients with nonmuscle invasive bladder cancer (NMIBC). Its second candidate FL116 is a human anti-programmed cell death protein 1 (PD-1) antibody site-specifically fused to an interleukin-18 (IL-18) variant with minimal binding affinity to the IL-18 binding protein (IL-18BP), and has demonstrated potent tumor-killing efficacy in multiple in vivo tumor models sensitive or resistant to immune checkpoint inhibitors.