Atara Biotherapeutics, INC Schedule 13D activist filings

Redmile Group, LLC and its affiliates have updated their Schedule 13D filing to reflect changes in beneficial ownership of Atara Biotherapeutics, Inc. following the exercise of pre-funded warrants.

Redmile Group reports a change in beneficial ownership percentage of Atara Biotherapeutics due to shifts in the issuer's outstanding share count.

Panacea Venture Healthcare Fund II, L.P. sold 313,446 shares of Atara Biotherapeutics common stock on May 7, 2026.

Panacea Venture entities, including James Huang, have updated their beneficial ownership in Atara Biotherapeutics, Inc., reporting a sale of shares and warrant exercises.

Redmile Group, LLC and its affiliates filed an amended Schedule 13D for Atara Biotherapeutics, Inc., updating beneficial ownership to 9.9% and adding Redmile Strategic Long Only Trading Sub, Ltd. as a reporting person.

Panacea Venture and its affiliates have increased their beneficial ownership in Atara Biotherapeutics, Inc. to 20.0% through recent open market purchases and warrant holdings.

Investment firm Redmile Group, LLC and its affiliates have significantly increased their beneficial ownership in Atara Biotherapeutics, Inc. to 9.9%, concurrently securing a board seat for managing director Nachi Subramanian.

Panacea Venture and its affiliated funds have disclosed a substantial investment in Atara Biotherapeutics, Inc., acquiring nearly 20% beneficial ownership and securing a board seat for James Huang.

Adiumentum Capital Fund I LP, along with its affiliates, has increased its beneficial ownership in Atara Biotherapeutics, Inc. to 19.99% following a recent registered offering.