Abstract 3329: Development of HM-001 as a therapeutic drug for non-muscle invasive bladder cancer

Abstract

Abstract HM-001 is a drug containing sodium chlorite as the active ingredient that is being developed as a drug for non-muscle invasive bladder cancer (NMIBC), and is currently undergoing physician-led clinical trials. It has been discovered that sodium chlorite generates radicals in an acidic environment, and phosphatidylserine on the surface of tumor cells acts as a Lewis acid to generate radicals. HM-001, like other anticancer drugs and BCG, is intended to be injected into the bladder, retained, and then excreted. GLP studies using the same administration method has been completed, and no toxic changes have been observed in human trial doses. The efficacy of HM-001 against NMIBC was evaluated using an orthotopic transplantation model of UM-UC-3, a bladder cancer cell line. In the model, cells were transplanted into the bladder of SCID mouse after epithelial removal with trypsin, 600, 800, 1,600, and 3,200 ppm of HM-001 were administered once a week, and the weight of the excised bladder was calculated. After 4 weeks, the tumor weight was calculated and the tumor weight suppression rate in the control group was evaluated. As a result, the medicinal efficacy was confirmed at concentrations of 800ppm or higher. On the other hand, the UM-UC-3 model is a commonly used model, but it mimics CIS (carcinoma in situ) and can only partially mimic NMIBC. That is, other models are needed to evaluate efficacy for low- and high-grade NMIBC other than CIS. Therefore, we established high-grade and low-grade PDX and evaluated the effectiveness of HM-001 against low- and high-grade PDX through ex vivo testing. First, patient-derived tissue was transplanted into SCID mice, allowed to grow, and then removed. After extraction, they were cut into 2 mm3 pieces, exposed to HM-001 at 800, 1600, and 3200 ppm for 2 hours, and then transplanted into SCID mice. As a result of comparing the tumor size after transplantation with the control group, a dose-dependent tumor regression effect was confirmed in high-grade and low-grade PDX. NMIBC is divided into low-, medium-, and high-risk categories, with different treatment methods and drugs used for each. In particular, low-grade forms are restricted to low- and intermediate-risk groups. The results of this study show that HM-001 is effective not only for high-risk (including CIS) NMIBC but also for low- and intermediate-risk (low-grade) NMIBC. Citation Format: Shinji Mima, Monta Sakaki, Noriaki Kiya, Atsunari Kawashima, Norio Nonomura, Chihaya Kakinuma. Development of HM-001 as a therapeutic drug for non-muscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3329.