UNITED STATES SECURITIES AND EXCHANGE COMMISSION ☐ 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: 001-39045 IGM Biosciences, Inc. WASHINGTON, DC 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, 2022 OR (Exact Name of Registrant as Specified in its Charter) Delaware 77-0349194 (State or other jurisd ...

Global Leaders in IgM Antibodies Corporate Overview September 2022 Forward-looking statements This presentation contain "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 that reflect the current views of IGM Biosciences, Inc. (the "Company," "we" or "our") with respect to the Company's future financial condition, results of operations, business strategy, expectations, milestones and plans, including our expectations regarding the transaction with Sanofi, ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 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 ☐ 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: 001-39045 IGM Biosciences, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 77-0349194 (State or other jurisdictio ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 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: 001-39045 IGM Biosciences, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 77-0349194 (State or other jurisdicti ...

Table of Contents Index to Financial Statements 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 001-39045 IGM Biosciences, Inc. (Exact name of Registrant as specified in its Charter) (S ...

Global Leaders in IgM Antibodies Corporate Overview February 10, 2022 Forward-looking statements This presentation contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 that reflect the current views of IGM Biosciences, Inc. (the "Company," "we" or "our") with respect to the Company's future financial condition, results of operations, business strategy, expectations, milestones and plans. All statements other than statements of historical fact could ...

Pioneering the Development of Engineered IgM Antibodies IGM Corporate Presentation November 2021 Forward-Looking Statements This presentation contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 that reflect the current views of IGM Biosciences, Inc. (the "Company," "we" or "our") with respect to the Company's future financial condition, results of operations, business strategy, expectations, milestones and plans. All statements other than statemen ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 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 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: 001-39045 IGM Biosciences, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 77-0349194 (State or other jurisd ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 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: 001-39045 IGM Biosciences, Inc. (Exact Name of Registrant as Specified in its Charter) Delaware 77-0349194 (State or other jurisdictio ...

Pioneering the Development of Engineered IgM Antibodies IGM Corporate Presentation RBC Capital Markets Global Healthcare Conference May 19, 2021 Forward-Looking Statements This presentation contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 that reflect the current views of IGM Biosciences, Inc. (the "Company," "we" or "our") with respect to the Company's future financial condition, results of operations, business strategy, expectations, mileston ...