Theralase's Rutherrin data point to effectiveness

Executive Summary

• Theralase Technologies presented preclinical data demonstrating that X-ray-activated Rutherrin significantly enhances the efficacy of radiation therapy in destroying muscle invasive bladder cancer (MIBC) compared to radiation alone.
• The company plans to conduct a phase 0/1/2 adaptive clinical study with radiation-activated Rutherrin (with or without chemotherapy and/or immunotherapy) for MIBC patients, subject to regulatory approval, as an alternative to radical cystectomy or trimodal therapy.
• In vivo studies showed complete tumour clearance in mice treated with Rutherrin and fractionated radiation, whereas radiation alone resulted in persistent tumour growth and high mortality.

Key Details

• Preclinical Efficacy (In Vitro): Rutherrin combined with 2.5 Gray X-ray radiation resulted in significantly greater cell death in mouse MIBC cells (MBT-2) compared to radiation alone.
• Tumour Selectivity: Tissue analysis showed tumour sites had approximately four times higher Rutherrin levels than normal bladder tissue, demonstrating a favourable therapeutic index.
• In Vivo Survival and Clearance: In an orthotopic MIBC mouse model, mice treated with systemic Rutherrin and fractionated radiation (total cumulative dose of 25 Gray) showed 100% survival and complete tumour clearance by day 35.
• Control Group Outcomes: In the radiation-only group, mice exhibited persistent and larger tumour volumes; 50% reached humane end points, and the remaining 50% displayed steady tumour growth.
• Clinical Strategy: Theralase intends to pursue clinical development of Rutherrin as a radiation sensitizer for MIBC, glioblastoma multiforme (GBM), and non-small-cell lung cancer (NSCLC).
• Market Context: Approximately 25% of new bladder cancer cases in the US (83,000+) and Canada (13,300+) are MIBC, which carries a significant risk of death and currently relies on cisplatin-based chemotherapy followed by radical cystectomy or trimodal therapy.

Notable Quotes

• Mark Roufaiel, PhD, Research Scientist: "These preclinical findings demonstrate that Rutherrin selectively accumulates in MIBC tumours versus health bladder tissue and significantly enhanced the therapeutic effect of radiation. Most importantly, we observed complete tumour clearance in X-ray-activated Rutherrin-treated animals even under low radiation dosing conditions."
• Arkady Mandel, MD, PhD, DSc, Chief Scientific Officer: "Preclinical data collected supports the clinical opportunity of employing X-ray-activated Rutherrin in the treatment of difficult-to-treat cancers such as glioblastoma multiforme, non-small-cell lung cancer... and now based on the recent data, MIBC... mice treated with a combination of Rutherrin and radiation therapy showed no detectable cancer."
• Roger DuMoulin-White, President, CEO and Chairman: "The combination of selective tumour uptake by Rutherrin, demonstrated X-ray enhancement in vitro, accelerated tumour regression and complete tumour destruction in vivo at low radiation doses collectively supports the executive decision by Theralase to pursue clinical development of Rutherrin... subject to regulatory approval."