New breakthrough in non-muscle invasive bladder cancer: Japanese clinical results of gene therapy ADSTILADRIN announced

At the 112 Annual Meeting of the Japan Association of Urology, the preliminary results of the latest 3 clinical study of an innovative treatment for non-muscle invasive bladder cancer (NMIBC) ADSTILADRIN attracted widespread attention. This study is led by Ferring Pharmaceuticals and focuses on Japanese patients who have not responded to BCG treatment. Preliminary data show that this gene therapy shows good clinical potential in terms of efficacy and safety.

The trial (No.NCT05704244) is currently ongoing and is targeting patients with BCG unresponsiveNMIBC. The patients were divided into two groups: one group was patients with carcinoma in situ (CIS) and high-grade Ta/T1 tumors, and the other group was patients with simple papillary tumors (Ta/T1). What was announced at this meeting was the patient data of CIS merged HG Ta/T1. The results showed that among the 20 Japanese patients who received ADSTILADRIN treatment, 75% n>Complete remission (CR) was achieved after 3 months of treatment, that is, 15 lesions completely disappeared.

In terms of safety, ADSTILADRIN also showed high tolerability. Data show that 80% of patients (16 people) experienced drug-related adverse reactions during treatment, and a total of 76 adverse events were recorded. Among them, most were grade 1 mild adverse reactions (accounting for more than 84%), and a few were grade 2 moderate reactions. Of concern is that no serious adverse events grade 3 or above were observed, indicating that this therapy has good safety and controllability in the Japanese population.

ADSTILADRINhas previously been approved by the United States in2022December FDAApproved for the treatment of high-risk NMIBC adult patients with no response to BCG and carcinoma in situ (which may be combined with papillary tumors). This is the first approved non-replicative intravesical gene therapy, which is of epoch-making significance. The therapy was approved based on the Phase 3CS-003 clinical study (NCT02773849), the study results showed that the complete remission rate was 51%, nearly half of the patients' remission could last more than one year, and the median duration of remission reached 9.7 months.

In addition to clinical trial data, a real-world study from the Mayo Clinic was also announced at the 2025 Urological Cancer Conference, which provides a strong complement to the clinical value of ADSTILADRIN. In the study, 79% of evaluable patients (n=24) achieved complete response at 3 months, and 84% of responders maintained response, with the median duration of response not reached during follow-up. In addition, among the 43 patients who received intravesical therapy, the survival rate without cystectomy was as high as 95% and the overall survival rate was 100%.

Overall, ADSTILADRIN’s performance in Japan’s 3 phase 3 trial is highly consistent with U.S. clinical and real-world data The degree is consistent, and even the three-month response rate is slightly higher, further confirming its clinical value in the treatment of patients with BCG ineffectiveNMIBC. Although the drug has not yet been officially launched in Japan, as trials progress and more data are accumulated, it is expected to bring new hope to more Asian patients in the future.

Reference materials:Ferring Unveils New Data with ADSTILADRIN® (nadofaragene firadenovec-vncg) at 112th Annual Meeting of the Japanese Urological Association’, press release. Ferring Pharmaceuticals; published 21 April 2025.