July 10 (Reuters) - Apnimed, a late-stage clinical pharmaceutical company, filed for an initial public offering in the U.S. on Friday. The biotech sector has staged a notable comeback as fresh capital flows back into the industry, improving market sentiment after a prolonged downturn. Initial public offerings in the biotech sector plunged to their lowest level in more than a decade in 2025. Founded in 2017, Apnimed is a clinical-stage company fo…