SUZHOU and SHANGHAI China, Feb 15, 2025 -Forlong Biotechnology, a clinical stage biotech dedicated to developing next-generation cytokine therapeutics, today announced that

the first patient of phase Ib has been dosed of its leading asset IL-15 super-agonist FL115. The open-label Phase Ib trial is designed to evaluate the safety and preliminary efficacy of FL115 (intravesical instillation) plus bacillus Calmette-Guérin (BCG) in patients with high-risk non-muscle-invasive bladder cancer（HR-NMIBC）.The clinical trial is being led by Fudan University Shanghai Cancer Center.

Dosing the first participant marks a critical milestone in advancing this novel immunotherapy. In the preceding Phase Ia study, FL115(intravesical instillation) monotherapy has already demonstrated preliminary antitumor activity, with tumor assessments showing no recurrence (NR) in multiple patients.

About FL115

IL-15 is a pleiotropic cytokine that binds to the IL-15Rα subunit on cells, thereby activating T, and natural killer cells and driving their proliferation and survival. Leveraging Forlong’s proprietary Fbody® platform, FL115 has been rationally engineered to overcome the short half-life, low potency and narrow therapeutic window of recombinant IL-15.Moreover, FL115 offers enhanced penetration into solid tumors, a simple and robust manufacturing process, and significantly lower production costs.These attributes position FL115 as a next-generation immuno-oncology agent with the potential to benefit a broad population of cancer patients.

About Forlong Biotechnology

Forlong Biotechnology is a clinical stage biotechnology company dedicated to developing next-generation cytokine therapeutics. Focusing on tumor immunology, Forlong develops engineering therapeutic cytokine combinations that act at distinct steps of the cancer–immunity cycle to treat cancer. The leading asset, FL115, is a clinical stage super agonist of interleukin-15 (IL-15) that can activate natural killer (NK) cells and memory T cells. Pre-clinical studies demonstrate FL115 has significantly wider therapeutic index than comparator IL-15 agents, enabling efficacious dosing at markedly higher exposure levels.