X0508 4 2025-08-15 0001604464 Atara Biotherapeutics, Inc. ATRA 0002010692 Panacea Innovation Ltd C/O MAPLES CORPORATE SERVICES LIMITED, UGLAND HOUSE GRAND CAYMAN E9 KY1-1104 CAYMAN ISLANDS false false true false 0001573160 Huang James C/O MAPLES CORPORATE SERVICES LIMITED, UGLAND HOUSE GRAND CAYMAN E9 KY1-1104 CAYMAN ISLANDS true false true false false Common Stock 2025-08-15 4 P false 55000 12.1895 A 1405000 I See Footnotes The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions ranging from $11.83 to $12.44, inclusive. The Reporting Person undertake to provide to the Issuer, any securityholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth above. Represents securities held by Panacea Venture Healthcare Fund II, L.P. James Huang is the sole owner of Panacea Innovation Limited, which is the sole owner of Panacea Venture Healthcare Fund II GP Company, Ltd. ("Fund II GP") and Panacea Opportunity Fund I GP Company, Ltd. ("Opportunity Fund GP"), which are the general partners of Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P. As a result, each of the Reporting Persons may be deemed to share beneficial ownership of the securities held of record by Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P., but each disclaims such beneficial ownership. Panacea Innovation Limited By: /s/ James Huang, Founding Managing Partner 2025-08-19 /s/ James Huang 2025-08-19