UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 ________________________________ FORM 10-Q ________________________________ ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number: 001-33958 SELLAS Life Sciences Group, Inc. (Exact name of registrant as specified in its charter) Delaware 20-8099 ...

| --- | --- | --- | --- | --- | --- | --- | |-----------------------|------------------|-------|-------|-------|-------|-------| | | | | | | | | | | | | | | | | | | | | | | | | | | Company Overview | | | | | | | NASDAQ: SLS June 2022 | | | | | | | | | | | | | | | | | | | | | | | ZELLAS CELLAS Forward Looking Statements This presentation contains forward-looking statements. Such forward-looking statements can be identified by the use of the words "expect," "believe," "will," "anticipate," "estimate," "plan," ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 ________________________________ FORM 10-Q ________________________________ ☒ 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 Commission File Number: 001-33958 SELLAS Life Sciences Group, Inc. (Exact name of registrant as specified in its charter) Delaware 20- ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 For the transition period from _________ to _________ Commission File Number: 001-33958 SELLAS Life Sciences Group, Inc. (Exact name of registrant as specified in its charter) ________________________________ ________________________________ 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, ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 ________________________________ FORM 10-Q ________________________________ ☒ 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 Commission File Number: 001-33958 SELLAS Life Sciences Group, Inc. (Exact name of registrant as specified in its charter) Delaware ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 ________________________________ FORM 10-Q ________________________________ ☒ 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 Commission File Number: 001-33958 (Exact name of registrant as specified in its charter) Delaware 20-8099512 (State of incorporation) ( ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 ________________________________ FORM 10-Q ________________________________ ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number: 001-33958 SELLAS Life Sciences Group, Inc. (Exact name of registrant as specified in its charter) Delaware 20- ...

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 For the transition period from _________ to _________ Commission File Number: 001-33958 SELLAS Life Sciences G ...

| --- | --- | --- | --- | --- | --- | |-------|-------|-------|-------|-------|-------| | | | | | | | | | | | | | | ΣΕΓΓΑΣ HID LIFE SCIENCES GROUP Forward Looking Statements This presentation contains forward-looking statements. Such forward-looking statements can be identified by the use of the words "expect," "believe," "will," "anticipate," "plan," "plan," "project" and other words of similar import. The forward-looking statements in this presentation include, but are not limited to, statements related t ...

| --- | --- | --- | --- | --- | --- | --- | |--------------|-------|------------------|-------|-------|-------|-------| | | | | | | | | | | | | | | | | | | | | | | | | | | | Company Overview | | | | | | NASDAQ: SLS | | | | | | | | January 2020 | | | | | | | | | | | | | | | | | | | | | | | ZELLAS FORWARD LOOKING STATEMENTS This presentation contains forward-looking statements. Such forward-looking statements can be identified by the use of the words "expect," "believe," "will," "anticipate," "estimate," "pla ...