ST. LOUIS - Results of a Phase III clinical study using botulinum toxin type A to treat primary axillary hyperhidrosis, or excessive underarm sweating, show that botulinum toxin type A is safe and effective for treatment of hyperhidrosis and that it markedly improves quality of life in patients who suffer from this medical condition. The data were announced today at the 2004 American Academy of Dermatology (AAD) annual meeting in Washington, D.C. by Dr. Dee Anna Glaser, Associate Professor of Dermatology and Vice Chairman, Department of Dermatology, at Saint Louis University School of Medicine, a lead investigator for the trials.
"Most people don't realize that hyperhidrosis is an extremely debilitating chronic condition that affects as many as eight million people in the U.S.," said Dr. Glaser. "As such, the results of this 52-week study using botulinum toxin type A treatment are very exciting because they mean that we are that much closer to having the first truly effective, non-surgical treatment available to meet the needs of patients who suffer from primary axillary hyperhidrosis."
The study found that four weeks after treatment with botulinum toxin type A (administered intradermally), 75 percent of patients receiving botulinum toxin type A vs. 25 percent on placebo achieved at least a 2-point improvement from baseline on the Hyperhidrosis Severity Scale (HDSS), a 4-point scale. Quantity of sweat production in the axillae was also significantly decreased.
"The Hyperhidrosis Severity Scale is an important new tool that physicians can use to identify hyperhidrosis patients who are in need of medical treatment, as well as to assess treatment results over time," explains Dr. Glaser. "It is our hope that physicians will begin to use this valid and reliable scale to quickly and accurately diagnose patients with hyperhidrosis who otherwise might not seek treatment."
The study also assessed the specific effects of primary axillary hyperhidrosis on patients' daily lives at study entry (prior to receiving treatment) and again four weeks after receiving his/her study treatment. It found that hyperhidrosis results in substantial occupational, psychological and physical impairment for the patient, and that botulinum toxin type A treatment markedly improved patients' quality of life as soon as four weeks after initial treatment.
"People who suffer from hyperhidrosis have a very hard time leading a normal life," said Dr. Glaser. "While there is a general misperception that hyperhidrosis is merely a disturbing hygienic issue, the condition should be taken seriously as it could lead to isolation and depression. It is important that physicians are made aware of hyperhidrosis and available treatment options to ensure patients receive proper diagnosis and are not just sent away with instructions to buy a stronger anti-perspirant."
Safety and Efficacy - Methodology and Results
Following screening, 322 patients were randomized to one of three treatment groups (50 units of botulinum toxin type A per underarm, 75 units of botulinum toxin type A per underam or placebo) and were evaluated at one week after treatment and every four weeks thereafter. The primary efficacy evaluation was patient assessment of hyperhidrosis severity using the Hyperhidrosis Disease Severity Scale (HDSS).
Four weeks after treatment session one, the following results were observed:
75 percent of patients in each botulinum toxin type A group and 25 percent of placebo patients achieved at least a two-grade improvement from baseline on the HDSS;
43 percent of patients treated with botulinum toxin type A required only one treatment for the entire one-year study period, versus 12 percent on placebo;
Mean sweat production was significantly decreased in both botulinum toxin type A groups four weeks after their initial treatment (82 percent, 87 percent and 22 percent decreases in the 50U, 75U and placebo groups respectively);
Upon completion of the study, 85 percent and 84 percent of patients treated with 50U and 75U of botulinum toxin type A respectively reported that they were much more satisfied with the current study treatment than with previous treatments, versus 20 percent of patients on placebo;
There was no difference between the 50U and 75U groups in terms of measured efficacy endpoints.
No serious treatment-related adverse events were reported. The most frequently reported treatment-related adverse events (>5 percent in any treatment group) were injection site pain, injection site hemorrhage and non-axillary sweating. The incidence of these events was not significantly different between groups.
In related research presented by Dr. Glaser at the meeting, data from the 322 patient study were used to assess the validity of the HDSS by correlating HDSS scores with items from the Dermatology Quality of Life Index and the HHIQ four weeks post-treatment. Construct validity and responsiveness were assessed by comparing post-treatment changes in HDSS score with changes in gravimetric sweat measurement and by comparing HDSS scores with various daily activity limitations due to excessive sweating as collected in a national survey mailed to 150,000 U.S. households.
Based on resulting data from these analyses, the HDSS was observed to have acceptable validity, reliability and responsiveness.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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