Sienna Biopharmaceuticals Inc. debuted on the Nasdaq Thursday with its shares gaining nearly 30 percent on its first day of trading. Chief Executive Dr. Frederick Beddingfield III rang the closing bell at the Nasdaq MarketSite in Times Square in recognition of the company’s initial public offering. In paperwork filed with the Securities and Exchange Commission this month, the company said it planned to raise $65 million by offering 4.3 million shares with an initial offering price between $14 and $16 per share. The Westlake Village startup develops clinical stage topical treatments used for skin conditions such as psoriasis, as well as treatments for acne and hair removal. The company acquired its lead products through an acquisition of U.K.-based pharmaceutical company, Creabilis, last December. In April, the company completed its Series B financing round, raising $40 million. Most of Sienna’s executive team came from another Westlake Village biotech, Kythera, which was acquired by Allergen in 2015 for $2.1 billion. Shares of Sienna (SNNA) closed up $4.25, or just more than 28 percent, to $19.25 on the Nasdaq.