* Treatment approved for patients over 9 years of age
* Sales expected to reach $250 mln-$300 mln by 2023 -Cowen
* Qbrexza expected to launch in October (Adds analyst comment, estimates; updates share move)
By Manas Mishra and Sharnya G
June 29 (Reuters) - Dermira Inc said on Friday its topical cloth for excessive armpit sweating was approved by the U.S. Food and Drug Administration, providing patients with an easy-to-use option for an often embarrassing condition.
Shares of the company were up more than 25 percent at $11.09 in trading before the bell.
The treatment, Qbrexza, works by blocking receptors responsible for sweat gland activation and can be used once a day, the company said in a statement.
About 10 million people are affected with the condition, known as primary axillary hyperhidrosis, which results in sweating beyond what is needed for regulating normal body temperature.
The condition can affect a person's psychological well-being and overall quality of life due to constant stressing over the appearance of underarm sweat marks and working to conceal them.
"What we hear from patients is, 'Wow, I'm glad it's not just me. I'm embarrassed to talk to somebody about it, or I talked to a physician who couldn't do anything about it,'" Chief Executive Officer Tom Wiggans told Reuters prior to the approval of the treatment.
Currently, Allergan's Botox injection is used to treat the condition. Other treatments include antiperspirants and costlier alternatives such as laser therapy, as well as localized surgery like liposuction to remove sweat glands.
Qbrexza, indicated to treat patients above the age of nine years, received a "broad" label, Cantor Fitzgerald analyst Louise Chen said.
"This is a differentiator for Dermira, especially when one thinks about patients who might choose between (Qbrexza) and other available treatments."
Dermira said it expected to launch the drug in October this year and that it was not aiming for a large prescribing base. Brokerage Cowen estimates sales of $250 million to $300 million by 2023 for the drug. (Reporting by Manas Mishra and Sharnya G in Bengaluru; Editing by Anil D'Silva)