WEST CONSHOHOCKEN, PA. and PALO ALTO, CA. — June 25, 1999 — U.S. Bioscience and ALZA Corporation announced that the U.S. Food and Drug Administration (FDA) has approved the use of Ethyol® (amifostine) in an important radiation therapy setting. The approval expands the uses of the drug to include the reduction of moderate-to-severe xerostomia (dry mouth) in patients undergoing post-operative radiation treatment for head and neck cancer, where the radiation port includes a substantial portion of the parotid glands.
Ethyol® is the first FDA-approved therapy to reduce radiation-induced xerostomia in cancer patients. Xerostomia – a chronic dry mouth condition – is a severe and often irreversible side effect of radiation therapy caused by damage to the salivary glands.
An estimated 40,000 people in the United States will be diagnosed with head and neck cancer in 1999, and a majority of these patients will receive radiation therapy.
“Ethyol is the first therapy to help limit the degree of xerostomia that many patients suffer as a result of radiation therapy,” said Walter J. Curran, Jr., M.D., group chairman of the Radiation Therapy Oncology Group (RTOG), professor and chairman of radiation oncology and clinical director of the Kimmel Cancer Center at Jefferson Medical College, Philadelphia. “The impact of xerostomia – which can make it difficult for patients to chew, swallow or speak – is difficult to overstate.”
In clinical trials, improvements in the subjective measurements of oral dryness were considered to be supportive of the efficacy of Ethyol.
In the United States, Ethyol® is marketed by ALZA and co-promoted by U.S. Bioscience, the developer of the product.
Data supporting the safety and efficacy of Ethyol for the reduction of xerostomia included data from a Phase III, open-label, prospective multi-center randomized trial involving more than 300 patients with head and neck cancer.
Approximately one month following treatment, 78 percent of patients given radiation alone experienced moderate to severe xerostomia, compared with 51 percent of patients treated with Ethyol prior to radiation. This represented a 35 percent reduction in the incidence of moderate to severe xerostomia with the use of Ethyol (p=<0.0001). Moreover, nine to 12 months after radiation therapy, 57 percent of the patients in this trial who had been treated with radiation alone were still experiencing moderate to severe xerostomia, as compared to 34 percent of the patients in the Ethyol arm (p=0.0016).
Treatment-related side effects of Ethyol reported by patients receiving the drug plus radiation in the Phase III study were nausea and vomiting, which were sometimes severe, hypotension, fever, allergic-type skin reactions, dizziness/lightheadedness, fatigue/lethargy, rigors/chills, sneezing, sleepiness/somnolence and flushing.
Of the 26 patients who discontinued the therapy due to side effects (17 percent), all but one continued radiation treatment following discontinuation of Ethyol.
The approval announced today specifically applies to patients undergoing post-operative radiation therapy, and Ethyol should not be administered in patients receiving definitive radiation therapy except in the context of a clinical trial.