Sound Pharmaceuticals Demonstrates No Interference With Cisplatin Anti-tumor Activity in Tumor Models Using Combined Oral Formulation to Prevent Drug Induced Hearing Loss.

March 3, 2005

Findings from a second study by Sound Pharmaceuticals, Inc. (SPI), on the prevention and treatment of cisplatin associated side effects using orally delivered SPI-3005/6, will be published later this year in the peer-reviewed journal “Anti-Cancer Drugs”.

SPI has extended previously published preclinical studies on acute cisplatin toxicity reduction in which SPI-3005/6 significantly reduced the amount of hearing loss and kidney damage seen in treated rats. “While the acute toxicity model provides great proof of concept, the real key is prevention of toxicity while retaining the anti-tumor activity of cisplatin. Now in two separate tumor models, we have demonstrated that the cisplatin is working on the tumor while damage to the rats’ hearing and other organs is minimized. We are pleased to announce the advancement of SPI-3005/6 past this critical hurdle in chemoprotection,” stated Eric Lynch, PhD, Vice President and Director of Research.

SPI-3005 is a potent small molecule mimic of the enzyme Glutathione Peroxidase (GPx). GPx is a key enzyme in the neutralization of reactive oxygen and nitrogen species (ROS/RNS) and is depleted by cisplatin exposure. SPI-3006 is a Xanthine Oxidase (XO) inhibitor already in use in some chemotherapy regimes for the reduction of hyperuricemia. Research findings indicate that XO levels can increase following cisplatin exposure. By combining a XO enzyme inhibitor with a GPx enzyme mimic, SPI researchers are able to reduce the amount of toxic ROS/RNS generated by cisplatin and better scavenge ROS/RNS in the tissues of the cochlea and kidney. “These data support SPI’s hypothesis that by acting on two separate biochemical pathways, we are able to achieve better chemoprotection than with either agent alone. SPI’s combined formula achieves chemoprotective efficacy without toxicity. In addition, protected animals had improved multi-organ function and morbidity and mortality rates,” stated Dr. Lynch.

SPI is planning a controlled clinical trial of SPI-3005/6 for the prevention of hearing loss due to cisplatin chemotherapy. SPI’s goal is to file an IND in 2005.

Sound Pharmaceuticals, Inc. is a drug development company focused on treating hearing loss. To date, Sound Pharmaceuticals’ drug discovery program has identified targets for the prevention of hearing loss and for the improvement of hearing in individuals with hearing loss. For more information please visit http://www.soundpharmaceuticals.com

CONTACT: Dr. Jonathan Kil, President & CEO, Sound Pharmaceuticals, Inc., 4010 Stone Way N Suite 120, Seattle WA 98103, jkil@soundpharmaceuticals.com, 206-634-2559.