X0202 SCHEDULE 13G/A 0001224962 XXXXXXXX LIVE 1 Common stock, $0.001 par value 06/30/2026 0001382101 SUTRO BIOPHARMA, INC. 869367201 111 OYSTER POINT BLVD. SOUTH SAN FRANCISCO CA 94080 Rule 13d-1(c) Perceptive Advisors LLC b DE 0 1304846 0 1304846 1304846 N 7.9 IA Joseph Edelman b X1 0 1304846 0 1304846 1304846 N 7.9 IN Perceptive Life Sciences Master Fund, Ltd. b E9 0 1304846 0 1304846 1304846 N 7.9 CO SUTRO BIOPHARMA, INC. 111 Oyster Point Blvd. South San Francisco, California 94080 The names of the persons filing this report (collectively, the "Reporting Persons") with respect to the Common Stock, $0.001 par value per share (the "Common Stock") of SUTRO BIOPHARMA, INC. (the "Issuer") are: (i) Perceptive Advisors LLC ("Perceptive Advisors") (ii) Joseph Edelman ("Mr. Edelman") (iii) Perceptive Life Sciences Master Fund, Ltd. (the "Master Fund") The address of the principal business office of each of the Reporting Persons is: 51 Astor Place, 10th Floor, New York, NY 10003 Perceptive Advisors is a Delaware limited liability company. Mr. Edelman is a United States citizen. The Master Fund is a Cayman Islands corporation. Y The information required by this item with respect to each Reporting Person is set forth in Rows 5 through 9 and 11 of the cover pages to this Schedule 13G. The ownership percentages reported are based on 16,572,171 shares of Common Stock outstanding as of August 7, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 12, 2026. Neither Perceptive Advisors nor Mr. Edelman directly holds any shares of Common Stock. The Master Fund directly holds 1,304,846 shares of Common Stock. Perceptive Advisors serves as the investment manager of the Master Fund and may be deemed to beneficially own the shares held by the Master Fund. Mr. Edelman is the managing member of Perceptive Advisors and may be deemed to beneficially own the shares held by the Master Fund. Perceptive Advisors: 7.9% Mr. Edelman: 7.9% Master Fund: 7.9% Perceptive Advisors: 0 Mr. Edelman: 0 Master Fund: 0 Perceptive Advisors: 1,304,846 Mr. Edelman: 1,304,846 Master Fund: 1,304,846 Perceptive Advisors: 0 Mr. Edelman: 0 Master Fund: 0 Perceptive Advisors: 1,304,846 Mr. Edelman: 1,304,846 Master Fund: 1,304,846 Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. Exhibit 99.1 - Joint Filing Agreement Perceptive Advisors LLC /s/ Joseph Edelman 08/14/2026 Joseph Edelman /s/ Joseph Edelman 08/14/2026 Perceptive Life Sciences Master Fund, Ltd. /s/ Joseph Edelman 08/14/2026