The startup sold 17 million shares at $17 apiece in an upsized initial public offering that secured 45% more than Attovia first anticipated and values the company at $767 million. As a private company, Attovia raised about $256 million in venture funding. ATTO-1310 targets IL-31, which Attovia calls the “itch cytokine.” Attovia sees it as a possible treatment of inflammatory skin conditions like eczema or chronic spontaneous urticarias. Overall, the sector has already surpassed the particularly low 11 IPO total recorded in 2025, data show.