UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR 5959 Horton Street, Suite 300 Emeryville, California Commission file number: 001-38663 Gritstone bio, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 47-4859534 (I.R.S. Employer Identification No.) 94608 (State or Other Jurisdiction of Incorporation or Organiz ...

Corporate Presentation Safe Harbor and Forward-Looking Statements This presentation contains forward-looking statements including, but not limited to, statements related to Gritstone bio, Inc.'s ("Gritstone", "we" or "our") preclinical and clinical product candidates, including GRANITE, SLATE, CORAL, and HIV programs. All statements other than statements of historical facts contained in this presentation, including statements regarding the timing of immunogenicity and clinical data for GRANITE, SLATE, and C ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-38663 Gritstone bio, Inc. (Exact Name of Registrant as Specified in its Charter) (State or Other Jurisdiction of Incorporation ...

Corporate Presentation March 2022 Safe Harbor and Forward-Looking Statements This presentation contains forward-looking statements including, but not limited to, statements related to Gritstone bio, Inc.'s ("Gritstone", "we" or "our") preclinical and clinical product candidates, including GRANITE, SLATE, CORAL, and HIV programs. All statements other than statements of historical facts contained in this presentation, including statements regarding the timing of immunogenicity and clinical data for GRANITE, S ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-38663 Gritstone bio, Inc. (Exact name of Registrant as specified in its Charter) Delaware 47-4859534 (State or other jurisdiction of ...

Corporate Presentation January 2022 Safe Harbor and Forward-Looking Statements 2 This presentation contains forward-looking statements including, but not limited to, statements related to Gritstone bio, Inc.'s ("Gritstone", "we" or "our") preclinical and clinical product candidates, including GRANITE, SLATE, CORAL, and HIV programs. All statements other than statements of historical facts contained in this presentation, including statements regarding the timing of immunogenicity and clinical data for GRANIT ...

Financial Status - Gritstone reported a cash position of approximately $216.4 million as of September 30, 2021 [4] - Research and Development expenses were $24.4 million for the three months ended September 30, 2021 [80] - General and Administrative expenses totaled $6.4 million for the three months ended September 30, 2021 [80] Pipeline Programs & Milestones - CORAL COVID-19 vaccine program targets spike protein + T cell Epitopes (TCE) [11] with Q1 2022 data expected from a booster trial in individuals aged 60+ [8, 81] and 1H 2022 data from a NIAID sponsored trial [8, 13] - Gritstone and Gilead are collaborating to develop an HIV-specific therapeutic vaccine, with a deal value of up to $785 million plus royalties [33] - GRANITE, an individualized neoantigen therapy, showed a 44% molecular response as measured by ctDNA reduction [41] - Phase 2 trial initiations in MSS-CRC for GRANITE are planned for 1H 2022, including 1L maintenance (Q1) and adjuvant settings (Q2) [42] - SLATE, an off-the-shelf neoantigen therapy, demonstrated ctDNA responses in 66% of patients with the KRASmut G12C-HLA A*02:01 complex [68] Technology & Platform - Gritstone's EDGE AI platform is used for target identification, with >70% Positive Predictive Value [3, 9] - The company utilizes vaccine delivery platforms, including viral and self-amplifying mRNA [3]

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 Gritstone bio, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 47-4859534 (State or Other Jurisdiction of Incorporation or Organization) 5959 Horton Street, Suite 300 Emeryville, California 94608 (Address of Principal Executive Offices) (Zip Code) (510) 871- ...

GTB-3550 TriKE™ safely activates and delivers IL-15 to NK cells, but not T cells, in immune suppressed patients with advanced myeloid malignancies, a novel paradigm exportable to solid tumors expressing HER2 or B7H3 J. Miller2, E. Warlick2, D. Vallera2, R. Wangen3, N. Zorko4, P. Hinderlie2, D. Lewis2, M. Felices4; 1 Medicine, Masonic Cancer Center – University of Minnesota, Minneapolis, MN, United States of America, 2Radiation Oncology, Masonic Cancer Center – University of Minnesota, Minneapolis, United St ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-38663 Gritstone bio, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 47-4859534 (State or Other Jurisdictio ...