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, Janus Henderson beneficially owns 1,825,651 shares of common stock. This position represents a significant increase from a previous 0.0% holding, establishing the firm as a major institutional shareholder. Janus Henderson Group plc serves as the ultimate parent company for several SEC-registered investment advisers, including Janus Henderson Investors US LLC and Janus Henderson Investors UK Limited. These subsidiary asset managers exercise shared voting and dispositive power over the shares on behalf of various managed portfolios, including investment companies and institutional accounts. The filing indicates that the securities were acquired in the ordinary course of business and not for the purpose of influencing or changing the control of the issuer. No individual managed portfolio holds more than 5% of the outstanding common stock.