Janus Henderson Group plc Establishes 5.8% Stake in Collegium Pharmaceutical, Inc.

Janus Henderson Group plc (JHG) filed a Schedule 13G on May 15, 2026, reporting a new 5.8% ownership stake in Collegium Pharmaceutical, Inc. (COLL). As of the event date on March 31, 2026, the filer beneficially owns 1,825,651 shares of common stock. Janus Henderson Group plc acts as the ultimate parent company for several SEC-registered investment advisers, including Janus Henderson Investors US LLC and Janus Henderson Investors UK Limited, which exercise investment and voting discretion over Managed Portfolios. The filing indicates that the shares are held in the ordinary course of business and not for the purpose of influencing or changing the control of the issuer. The reported holdings reflect shared voting and dispositive power over the entire 1,825,651 shares, with no sole power reported. This filing marks an increase from a previously reported 0.0% position, establishing Janus Henderson as a significant institutional shareholder in the pharmaceutical company.