IO 2.0 cytokine therapy leader Forlong Biotechnology secures first close of Series Pre-B financing to accelerate registrational clinical development of its products

Forlong Biotechnology, a clinical-stage biopharmaceutical company headquartered in Suzhou High-tech Zone, is dedicated to developing transformative cytokine therapies for patients with significant unmet medical needs. On the occasion of its seventh anniversary, the Company announced the first close of its nearly RMB 100 million Series Pre-B financing round. This first close was led by Fudan Innovation Capital, with participation from Changshu Guofa Venture and Suzhou CAMBRIAN. The proceeds will be primarily used to advance the Company's flagship IO 2.0 cytokine therapy product FL115 into registrational clinical trials, advance FL116 into clinical development, and continue to expand its technology platform and product pipeline.

Founded in 2019 and headquartered in Suzhou High-tech Zone, Forlong Biotechnology is an innovative clinical-stage biopharmaceutical company driven by synthetic immunology and focused on the development of cytokine and other protein therapeutics. The Company also has a research and development center in Shanghai. Founder Dr. Ying Tianlei is a Professor at the School of Basic Medical Sciences, Fudan University, a full-time mentor at Shanghai Innovation Institute, and a Distinguished Professor of the "Changjiang Scholars" program by the Ministry of Education. The executive team and core R&D personnel possess strong industry backgrounds, having previously worked at renowned pharmaceutical companies such as Johnson & Johnson, BMS, Pfizer, and Innovent Biologics.

Forlong Biotechnology has established a globally leading integrated synthetic immunology technology system, comprising four proprietary core technology platforms: the Fbody® long-acting platform, the Syntokine® novel synthetic cytokine platform, the Fc engineering platform, and the AI-powered macromolecule intelligent discovery platform. These four platforms enable multi-dimensional optimization of protein therapeutics, particularly cytokines, with the goal of overcoming the developability challenges of cytokines and developing novel biologics with high safety profiles and excellent efficacy. To date, the Company has entered into multiple R&D collaborations with Henlius, Innovent Biologics, and Humanwell Healthcare, with its technological capabilities and product value widely recognized by the industry.

Forlong Biotechnology's lead pipeline candidate, FL115, is an engineered IL-15/IL-15Rα-Fbody fusion protein. IL-15 activates natural killer (NK) cells and memory T cells, demonstrating significant potential in cancer immunotherapy. Fbody® is an engineered single-chain Fc that retains FcRn affinity while eliminating binding to Fcγ receptors and the complement system, thereby optimizing protein half-life and biodistribution.

Following the completion of its RMB 110 million Series A financing round in 2023, Forlong Biotechnology successfully advanced FL115 into clinical development and has administered the product to over 90 patients with advanced solid tumors and non-muscle invasive bladder cancer (NMIBC) across multiple clinical centers in China and the United States. Clinical data have shown that intravenous infusion of FL115 as a monotherapy has demonstrated a favorable safety profile and preliminary efficacy in patients with advanced solid tumors, making it the only IL-15 superagonist to achieve a partial response (PR) as a monotherapy, with global best-in-class potential. In the completed Phase I clinical trial, FL115 monotherapy achieved a disease control rate (DCR) of 39%, including partial responses and stable disease. Notably, one patient with advanced cervical cancer has achieved stable disease for over 20 months, and two patients with confirmed PR (cPR) have experienced duration of response exceeding 12 months and 10 months, respectively—significantly better than other IL-15 products. Furthermore, FL115 features a robust manufacturing process with low production costs, offering a significant cost advantage and pricing flexibility.

In addition, Forlong Biotechnology has constructed a differentiated IL-18 library containing over 100 IL-18 mutants that are completely non-binding to IL-18 binding protein (IL-18BP). The PD-1/IL-18 bispecific antibody FL116, developed from this library, has demonstrated potent tumor-killing activity across multiple in vivo tumor models and has shown a favorable safety profile in non-human primate (NHP) preclinical toxicology studies. Furthermore, the Company is continuously advancing its early-stage research efforts to explore the development potential of other cytokine targets.