Safety evaluation of targeted osmotic lysis therapy in Beagles.

Objective: The objective of this study was to satisfy the US FDA's Center for Devices and Radiological Health regarding the safety of targeted osmotic lysis (TOL), a novel treatment for advanced carcinomas, in Beagle dogs.

Methods: 12 intact Beagle dogs, 6 males and 6 females, were divided into 2 treatment groups of 6, each receiving 3 TOL cycles. For each 6-day cycle, digoxin was administered orally at 0.007 mg/kg q 12 h X 6 days to achieve steady-state plasma concentrations. On days 5 and 6 of each cycle, the animals were exposed to pulsed electric field (PEF) stimulation at a field strength of either 18 or 40 V/min for 2 hours. Following the completion of cycles 1 and 2, animals were observed for 7 days. On the day following the end of cycle 3, the animals were euthanized. A complete macroscopic examination was performed, and tissues were collected for microscopic examination.

Results: As there were no concurrent untreated control animals, only qualitative comparisons were performed to assess potential differences between group 1, which received the digoxin plus 18 V/min PEF, and group 2, which received digoxin plus 40 V/min PEF. No adverse events related to TOL exposure were observed in either group.

Conclusions: Neither group demonstrated gross or microscopic lesions following 3 rounds of exposure to TOL.

Clinical relevance: Due to the lack of toxicity noted in the treated animals, TOL warrants consideration as either a standalone treatment option or as an adjunct to surgery or chemotherapy for managing malignant cancer.