Forlong Biotechnology Initiates Phase 2 Trial of IL-15 Superagonist FL115 Combined with BCG for Non-Muscle Invasive Bladder Cancer
核心洞察
Forlong Biotechnology (搜索) has dosed the first patient in a phase 2 clinical trial evaluating FL115, an engineered IL-15 (搜索) superagonist, in combination with BCG for non-muscle invasive bladder cancer treatment.
The open-label study will enroll patients across three arms including BCG-unresponsive carcinoma in situ, BCG-unresponsive high-risk papillary disease, and BCG-naïve medium to high-risk NMIBC patients.
Phase 1 monotherapy data showed promising efficacy with 4 of 6 patients achieving responses lasting at least 3 months at the recommended dose for expansion.
Forlong Biotechnology (搜索) has announced the dosing of the first patient in a phase 2 clinical trial investigating FL115, an engineered interleukin-15 (IL-15 (搜索)) superagonist, in combination with Bacillus Calmette-Guérin (BCG) for patients with non-muscle invasive bladder cancer (NMIBC). The milestone represents a significant advancement for the clinical-stage biotech company's lead therapeutic candidate.
Trial Design and Patient Population
The open-label phase 2 study is designed to evaluate three distinct patient populations across 12-15 clinical trial sites in China. The trial arms include patients with BCG-unresponsive NMIBC with carcinoma in situ (CIS), BCG-unresponsive high-risk papillary NMIBC, and BCG-naïve medium to high-risk NMIBC patients.
Eligible participants must refuse or be unsuitable for radical cystectomy, maintain an ECOG performance score of 0 to 2, have an expected survival of at least 2 years, and demonstrate adequate organ function. The study is expected to complete enrollment by October 2028.
Primary Endpoints and Efficacy Measures
The trial will assess different primary endpoints based on patient population. For patients with carcinoma in situ, investigators will measure complete response rate and duration of response. In patients with papillary disease, the study will evaluate disease-free survival and relapse-free survival as key efficacy parameters.
Promising Phase 1 Foundation
The phase 2 trial builds upon encouraging data from the phase 1 portion, which evaluated FL115 as monotherapy in NMIBC patients. At the recommended dose for expansion, 4 of 6 patients achieved responses lasting at least 3 months, with 2 patients maintaining responses for at least 9 months. These results demonstrated both favorable safety and preliminary efficacy signals that support advancement to combination therapy.
FL115 Mechanism and Development Strategy
FL115 is an engineered IL-15 (搜索)/IL15Rα-Fbody fusion protein designed to enhance anti-tumor immunity through IL-15-mediated signaling on natural killer (NK) cells and CD8+ T cells while minimizing complexity from Fc regions. The therapeutic approach aims to leverage the immune-stimulating properties of IL-15 while maintaining a robust manufacturing process with excellent product stability.
"Dosing the first patient in our Phase 2 trial for FL115 marks a defining moment for Forlong, as we advance our lead candidate further into clinical development and continue to validate the potential of our synthetic immunology platforms," said Dong Wei, PhD, CEO of Forlong Biotechnology (搜索).
Broader Clinical Development Program
Beyond NMIBC, FL115 is being investigated in combination with anti-PD1 monoclonal antibodies in a phase 1b/2 clinical trial for patients with advanced solid tumors. Interim data from this advanced solid tumor study is scheduled for presentation as a late-breaking abstract at the 40th Annual Meeting of the Society for Immunotherapy of Cancer (SITC 2025) on November 8.
Wei emphasized the therapeutic potential of FL115 across multiple indications: "FL115 stands out with favorable safety and preliminary efficacy observed in multiple Phase 1 clinical studies in advanced solid tumors and NMIBC. This trial gives us the opportunity to further validate FL115 as potential Best-in-class IL-15 (搜索) superagonist, and bring new treatment options for cancer patients in need."