Forlong Biotechnology Announces Successful Completion of GMP Pivotal Batch Production for FL115 (IL-15 Superagonist), Ready to Support Upcoming Phase III Clinical Trial in Non-Muscle Invasive Bladder Cancer (NMIBC)

SHANGHAI & SUZHOU, China--(BUSINESS WIRE)--Forlong Biotechnology, a clinical-stage biotech company focused on developing transformative cytokine therapies for patients with severe unmet needs, today announced that its manufacturing partner, JOINN Biologics, has successfully completed production of the FL115 pivotal batch, which will support the company’s upcoming Phase III clinical trial in non-muscle invasive bladder cancer (NMIBC).

FL115 is an engineered IL-15/IL-15Rα-Fbody^® fusion protein. Fbody^® is a single-chain Fc engineered to preserve FcRn affinity while eliminating binding to FcγRs and complement systems, with the goal of optimizing protein half-life and biodistribution. FL115 drug substance and drug product have demonstrated excellent stability and solubility at concentrations up to 20 mg/mL, supported by a robust, low-cost GMP manufacturing process.

A clinical study of FL115 (NCT07122414) in BCG-unresponsive NMIBC is ongoing. Following the first patient dosing in August 2024, 10 patients have been dosed with FL115 alone and 52 patients have been dosed with FL115 at 3 dose levels in combination with BCG, all via intravesical delivery.

“FL115 in combination with BCG has shown impressive safety and efficacy data in patients with BCG-unresponsive NMIBC, with the potential to be the best-in-disease therapy,” said Dong Wei, Ph.D., Chief Executive Officer of Forlong Biotechnology. “Successfully manufacturing and releasing the pivotal batch is an important milestone for the FL115 program, and we greatly appreciate the professional expertise and diligent effort of JOINN Biologics as our manufacturing partner. Together, we will advance FL115 into the pivotal Phase III clinical trial for NMIBC in 2027.”

About FL115

FL115 is an engineered IL-15/IL-15Rα-Fbody^® fusion protein designed to enhance anti-tumor immunity through IL-15-mediated signaling on NK and CD8+ T cells, while minimizing the complexity associated with an Fc domain. FL115 has demonstrated significant anti-tumor activity in vivo, both as a monotherapy and in combination therapy, and can be manufactured through a robust, efficient process with excellent product stability. Clinically, FL115 has shown a favorable safety profile and preliminary clinical responses as a monotherapy, and has best-in-class potential to synergize with current and emerging T cell–targeting immunotherapies through combination approaches that could meaningfully improve treatment outcomes for patients.

FL115 is currently being investigated in combination with Bacillus Calmette-Guérin (BCG) in a Phase II clinical trial evaluating safety and preliminary efficacy in patients with non-muscle invasive bladder cancer (NMIBC), and in combination with an anti-PD-1 monoclonal antibody in a Phase I clinical trial evaluating safety and preliminary efficacy in patients with advanced solid tumors. A Phase I clinical trial of FL115 subcutaneous injection is also being initiated in Australia.

About Forlong Biotechnology

Forlong Biotechnology is a clinical-stage biotech company focused on developing transformative cytokine therapies for cancer patients with severe unmet needs. The company has established four proprietary synthetic immunology platforms: the Fbody^® Long-acting Technology Platform, the Fc Engineering Platform, the Syntokine^® Synthetic Cytokine Platform, and an AI-driven Intelligent Biomolecular Discovery Platform.

Forlong’s lead candidate, FL115, is an interleukin-15 (IL-15) superagonist with best-in-class potential, currently being advanced in combination with an anti-PD-1PD-1 antibody in a Phase I study for patients with solid tumors, and in combination with BCG in a Phase II study for patients with NMIBC. The company’s second candidate, FL116, is a PD-1 antibody fused with an interleukin-18 (IL-18) mutein engineered to bind the IL-18 receptor without binding IL-18BP (a decoy receptor), and has demonstrated potent tumor-killing efficacy across multiple in vivo tumor models resistant to immune checkpoint inhibitors.