Developing PHY906 as a modulator in cancer chemotherapy

 

Shwu-Huey Liu

 

PHY906, a Chinese medicinal formulation consisting of four herbs, was first described in the Chinese Pharmacopia some 1800 years ago and has traditionally been used to alleviate various gastrointestinal ailments.  In addition, the individual herbs of PHY906 have, reportedly, a variety of pharmacological activities including antiviral activity, immunological stimulation, signal transduction, analgesic activity, vasodilatation, liver protection, nausea reduction, diarrhea treatment, antioxidation and appetite improvement.  The apparent efficacy of this formulation in relieving multiple symptoms gave rise to the idea that PHY906 could potentially benefit patients undergoing cancer chemotherapy.  PHY906 has been found, in mouse models, to not only reduce host toxicity, it also enhances the antitumor activity of cancer chemotherapeutics, including irinotecan. These preclinical studies also demonstrate that the metabolism of these anticancer drugs has not been altered with the co-administration of PHY906. Multiple factors are involved in PHY906’s mechanism of drug action.  All the four herbs in PHY906 are essential in the achievement of the antitumor effect and the reduction of host toxicity. The omission of any one of the four herbs compromises some or all of the effects of PHY906.  The US FDA requires that an herbal formula be safe, efficacious and consistent before it is approved as prescription medicine. We have developed comprehensive biological and chemical fingerprints to ensure the quality of PHY906. A clinical study of PHY906 for treating the life threatening side effects caused by irinotecan-based chemotherapy in patients with advanced colorectal cancer has been initiated in the United States.

 

 

 

Proceedings of 3^rd TWGHS-CUHK Eddie Wang Symposium on Complementary Chinese and Western Medicine Integrated Approach. p. 69 (2002)