Shares of Daré Bioscience Inc. /zigman2/quotes/203460984/composite DARE 0.00% rocketed 129% on very heavy volume toward a 13-month high in afternoon trade Monday, after the biopharmaceutical company announced positive findings for the use of its DARE-VVA1 product candidate in treating vulvar and vaginal atrophy (VVA). The stock was the biggest percentage gainer listed on major U.S. exchanges, even though it pared earlier gains of as much as 253%. Volume swelled to 37.8 million shares, compared with the full-day average of about 82,500 shares and enough to make the stock the most active on the Nasdaq exchange. The company said a self-administered vaginal suppository containing tamoxifen administered to four healthy postmenopausal women with VVA showed "significant improvements" in reducing vaginal pH and vaginal dryness, without significant absorption of tamoxifen. "If successful, DARE-VVA1 could be the first and only vaginally administered tamoxifen product approved by the FDA for the treatment of VVA in hormone-receptor positive breast cancer patients," the company said in a statement. The stock has now more than tripled year to date (up 218%), while the iShares Nasdaq Biotechnology ETF /zigman2/quotes/206189322/composite IBB -0.02% has climbed 18% and the S&P 500 /zigman2/quotes/210599714/realtime SPX +0.36% has gained 13%.