BDC-1001 Clinical Trial & Data - BDC-1001 is undergoing Phase 1/2 clinical trials for HER2-expressing solid tumors and has been well-tolerated in 20 patients as of January 29, 2021, showing signs of clinical activity including a Partial Response (PR)[3, 8, 51] - Preliminary clinical results for BDC-1001 demonstrate promising clinical activity, including a 39% reduction in tumor lesions in a patient with MSS colon cancer after 4 cycles of treatment [14, 16] - Additional patients treated with BDC-1001 showed evidence of disease control, including confirmed stable disease in patients with endometrial and metastatic colorectal cancer [18, 19] Boltbody™ ISAC Platform & Pipeline - Bolt Biotherapeutics is pioneering a new class of immuno-oncology products with its first-in-class Boltbody™ ISAC, BDC-1001, and a broadly enabling platform technology [3, 51] - The company's pipeline includes BDC-2034, a CEA-directed Boltbody ISAC, and a PD-L1 Boltbody ISAC program, targeting various solid tumors [6, 33] - Preclinical data demonstrates that ISACs of diverse tumor-targeting antibodies have dramatically improved efficacy [3, 51] Financial Position & Milestones - Bolt Biotherapeutics has pro-forma cash of $316.4 million expected to fund operations into 2023, supporting key milestones for BDC-1001 and BDC-2034 [3, 51] - Meaningful catalysts to drive value include data from the BDC-1001 monotherapy dose escalation study in 2H21, initiation of monotherapy dose expansions & anti-PD-1 combination dose escalation in 2H21, and initiation of a first-in-human clinical trial for BDC-2034 in 2022 [5, 53] HER2+ Breast Cancer Market Opportunity - The annual drug-treated breast cancer incidence includes 75,800 HER2+ patients, 86,900 HER2 Low (IHC 2+/ISH-) patients, and 155,500 HER2 Low (IHC 1+/ISH-) patients, indicating a significant unmet need in HER2-low cancers [21]

Table of Contents 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, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 | --- | --- | |--------------------------------------------------------------------------------------------------|-----------------------------------------------------| | | | | ...

| --- | --- | --- | --- | --- | --- | --- | --- | |-------|-------|-------|-------|-------|-------|-------|-------| | | | | | | | | | | | | | | | | | | Disclaimer This presentation contains forward-looking statements that involve substantial risks and uncertainties. All statements other than statements of historical facts contained in this presentation, including statements regarding Bolt Biotherapeutics, Inc. (the "Company," "we," "us," or "our")'s future financial condition, results of operations, busines ...