Nature of the Business and Basis of Presentation	6 Months Ended
Jun. 30, 2023
Accounting Policies [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Seres Therapeutics, Inc. (the “Company”) was incorporated under the laws of the State of Delaware in October 2010 under the name Newco LS21, Inc. In October 2011, the Company changed its name to Seres Health, Inc., and in May 2015, the Company changed its name to Seres Therapeutics, Inc. The Company is a commercial-stage microbiome therapeutics company focused on the development and commercialization of a novel class of biological drugs, which are designed to treat disease by modulating the microbiome to restore health by repairing the function of a disrupted microbiome to a non-disease state. The Company’s product, VOWST (fecal microbiota spores, live brpk), formerly called SER-109, was approved by the U.S. Food and Drug Administration (“FDA”) on April 26, 2023 and is the first and only orally administered microbiome therapeutic. VOWST is indicated to prevent the recurrence of Clostridioides difficile infection (“CDI”) in patients 18 or older following antibacterial treatment for recurrent CDI. The Company launched VOWST in the United States with its collaborator, Nestlé Health Science (“Nestlé”), in June 2023. Beginning with the commercial launch of VOWST, pursuant to the 2021 License Agreement (as defined below), Nestlé records total net sales of VOWST, which are reduced by costs incurred by each collaborator, and the resulting profit or loss is shared equally between the Company and Nestlé. For additional information, see Note 13, Collaboration Profit and Loss. Building upon VOWST, the Company is developing therapeutic candidates, such as SER-155, to specifically target infections and antimicrobial resistance. SER-155, a microbiome therapeutic candidate consisting of a 16-strain consortium of cultivated bacteria, is designed to prevent enteric-derived infections and resulting blood stream infections, as well as induce immune tolerance responses to reduce the incidence of Graft versus Host Disease ("GvHD") in patients undergoing allogeneic hematopoietic stem cell transplantation (“allo-HSCT”). Gastrointestinal microbiome data from the first 100 days of SER-155 Phase 1b open-label study cohort 1 showed the successful engraftment of SER-155 bacterial strains, and a substantial reduction in the cumulative incidence of pathogen domination, a biomarker associated with the risk of serious enteric infections and resulting bloodstream infections, as well as GvHD. The tolerability profile observed was favorable, with no serious adverse events attributed to SER-155 administration. Enrollment in the placebo-controlled cohort 2 portion of the study is ongoing and 100-day topline results are anticipated in mid-2024. The Company is progressing additional preclinical stage programs to evaluate how microbiome therapeutics may reduce incidence of infection, which the Company refers to as Infection Protection, in indications such as cancer neutropenia, chronic liver disease, solid organ transplant, and antimicrobial resistant infections more broadly in settings of high-risk such as intensive care units. The Company is also continuing its research activities in ulcerative colitis ("UC"), including evaluating the potential to utilize biomarker-based patient selection and stratification for future studies. In addition, the Company continues to leverage microbiome pharmacokinetic and pharmacodynamic data from across its clinical and preclinical portfolios, using its reverse translational microbiome therapeutic development platform to conduct research on various indications, including inflammatory and immune diseases, cancer, and metabolic diseases. The Company has built and deploys a reverse translational platform for the discovery and development of microbiome therapeutics. This platform incorporates high-resolution analysis of human clinical data to identify microbiome biomarkers associated with disease and non-disease states; preclinical screening using human cell-based assays and in vitro/ex vivo and in vivo disease models customized for microbiome therapeutics; and microbiological capabilities and a strain library that spans broad biological and functional breadth to both identify specific microbes and microbial metabolites that are associated with disease and to design consortia of bacteria with specific pharmacological properties. The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. The Company's primary focus in recent months has been and will continue to be supporting commercialization, including the manufacture of VOWST, which requires capital and resources. Other than VOWST, the Company’s product candidates are in development, and will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to potential commercialization. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, or maintained, that any product candidate developed will obtain necessary government regulatory approval, or that any approved product will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The accompanying condensed consolidated financial statements have been prepared on a basis which assumes that the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the normal course of business. As of June 30, 2023, the Company had an accumulated deficit of $889,133 and cash and cash equivalents of $229,520. For the six months ended June 30, 2023, the Company incurred a net loss of $24,622 and had net operating cash outflows of $10,600. The Company expects that its operating losses and negative cash flows will continue for the foreseeable future. In the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, the Company disclosed that there was substantial doubt about its ability to continue as a going concern as a result of conditions that existed as of the date of issuance of the consolidated financial statements included therein. At that time, primarily as a result of the increased and costly efforts to prepare for potential commercialization of VOWST, in conjunction with the Company's research and development efforts for other preclinical and product candidates, the Company determined that it would need additional funding in early 2024. Because certain elements of management's plans to mitigate the conditions that raised substantial doubt about the Company’s ability to continue as a going concern were contingent upon the approval by the FDA of the Biologics License Application ("BLA") for VOWST, and such approval was outside the Company's control, those elements could not be considered probable according to Accounting Standards Codification (“ASC”) 205-40, Going Concern ("ASC 205-40"), and therefore also could not be considered in the evaluation of mitigating factors. In May 2023, after FDA approval of VOWST, the Company received a $125,000 milestone payment under its license agreement with Nestlé executed in July 2021 (“2021 License Agreement,” see Note 12, Revenue from Contracts with Customers). Additionally, the Company is eligible to receive payments from Nestlé for the supply of VOWST, and is entitled to share equally in its commercial profits and losses. As of the date of issuance of these condensed consolidated financial statements, management’s plans to mitigate the conditions that raised substantial doubt about the Company’s ability to continue as a going concern include receipt of payments from Nestlé for the supply of VOWST, and sharing equally in commercial profits and losses with Nestlé pursuant to the 2021 License Agreement. Management concluded these plans are probable of being effectively implemented and of mitigating the conditions that raised substantial doubt about the Company’s ability to continue as a going concern. The Company expects that its cash and cash equivalents as of June 30, 2023 will be sufficient to fund its operating expenses, capital expenditure requirements, and debt service obligations for at least the next 12 months from issuance of these condensed consolidated financial statements. The Company may seek to raise additional capital through financing or other transactions, including through at the market equity offerings. The future viability of the Company beyond 12 months from issuance of these condensed consolidated financial statements is dependent on its ability to raise additional capital to finance its operations. Unaudited Interim Financial Information The accompanying unaudited condensed consolidated financial statements as of June 30, 2023 and for the three and six months ended June 30, 2023 and 2022 have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited condensed consolidated financial statements and the notes thereto for the year ended December 31, 2022 included in the Company’s annual report on Form 10-K for the fiscal year ended December 31, 2022, which was filed with the SEC on March 7, 2023 (the “Annual Report”). The unaudited condensed consolidated interim financial statements have been prepared on the same basis as the audited consolidated financial statements. The condensed consolidated balance sheet at December 31, 2022 was derived from audited annual financial statements, but does not contain all of the footnote disclosures from the annual financial statements. In the opinion of management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments which are necessary for a fair statement of the Company’s financial position, results of operations, and cash flows for the periods presented. Such adjustments are of a normal and recurring nature. The results of operations for the three and six months ended June 30, 2023 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2023.

Nature of the Business and Basis of Presentation

6 Months Ended

Jun. 30, 2023

Nature of the Business and Basis of Presentation

1. Nature of the Business and Basis of Presentation

Seres Therapeutics, Inc. (the “Company”) was incorporated under the laws of the State of Delaware in October 2010 under the name Newco LS21, Inc. In October 2011, the Company changed its name to Seres Health, Inc., and in May 2015, the Company changed its name to Seres Therapeutics, Inc. The Company is a commercial-stage microbiome therapeutics company focused on the development and commercialization of a novel class of biological drugs, which are designed to treat disease by modulating the microbiome to restore health by repairing the function of a disrupted microbiome to a non-disease state.

The Company’s product, VOWST (fecal microbiota spores, live brpk), formerly called SER-109, was approved by the U.S. Food and Drug Administration (“FDA”) on April 26, 2023 and is the first and only orally administered microbiome therapeutic. VOWST is indicated to prevent the recurrence of Clostridioides difficile infection (“CDI”) in patients 18 or older following antibacterial treatment for recurrent CDI. The Company launched VOWST in the United States with its collaborator, Nestlé Health Science (“Nestlé”), in June 2023. Beginning with the commercial launch of VOWST, pursuant to the 2021 License Agreement (as defined below), Nestlé records total net sales of VOWST, which are reduced by costs incurred by each collaborator, and the resulting profit or loss is shared equally between the Company and Nestlé. For additional information, see Note 13, Collaboration Profit and Loss.

Building upon VOWST, the Company is developing therapeutic candidates, such as SER-155, to specifically target infections and antimicrobial resistance. SER-155, a microbiome therapeutic candidate consisting of a 16-strain consortium of cultivated bacteria, is designed to prevent enteric-derived infections and resulting blood stream infections, as well as induce immune tolerance responses to reduce the incidence of Graft versus Host Disease ("GvHD") in patients undergoing allogeneic hematopoietic stem cell transplantation (“allo-HSCT”). Gastrointestinal microbiome data from the first 100 days of SER-155 Phase 1b open-label study cohort 1 showed the successful engraftment of SER-155 bacterial strains, and a substantial reduction in the cumulative incidence of pathogen domination, a biomarker associated with the risk of serious enteric infections and resulting bloodstream infections, as well as GvHD. The tolerability profile observed was favorable, with no serious adverse events attributed to SER-155 administration. Enrollment in the placebo-controlled cohort 2 portion of the study is ongoing and 100-day topline results are anticipated in mid-2024.

The Company is progressing additional preclinical stage programs to evaluate how microbiome therapeutics may reduce incidence of infection, which the Company refers to as Infection Protection, in indications such as cancer neutropenia, chronic liver disease, solid organ transplant, and antimicrobial resistant infections more broadly in settings of high-risk such as intensive care units. The Company is also continuing its research activities in ulcerative colitis ("UC"), including evaluating the potential to utilize biomarker-based patient selection and stratification for future studies. In addition, the Company continues to leverage microbiome pharmacokinetic and pharmacodynamic data from across its clinical and preclinical portfolios, using its reverse translational microbiome therapeutic development platform to conduct research on various indications, including inflammatory and immune diseases, cancer, and metabolic diseases. The Company has built and deploys a reverse translational platform for the discovery and development of microbiome therapeutics. This platform incorporates high-resolution analysis of human clinical data to identify microbiome biomarkers associated with disease and non-disease states; preclinical screening using human cell-based assays and in vitro/ex vivo and in vivo disease models customized for microbiome therapeutics; and microbiological capabilities and a strain library that spans broad biological and functional breadth to both identify specific microbes and microbial metabolites that are associated with disease and to design consortia of bacteria with specific pharmacological properties.

The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies.

The Company's primary focus in recent months has been and will continue to be supporting commercialization, including the manufacture of VOWST, which requires capital and resources. Other than VOWST, the Company’s product candidates are in development, and will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to potential commercialization. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, or maintained, that any product candidate developed will obtain necessary government regulatory approval, or that any approved product will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales.

The accompanying condensed consolidated financial statements have been prepared on a basis which assumes that the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the

normal course of business. As of June 30, 2023, the Company had an accumulated deficit of $889,133 and cash and cash equivalents of $229,520. For the six months ended June 30, 2023, the Company incurred a net loss of $24,622 and had net operating cash outflows of $10,600. The Company expects that its operating losses and negative cash flows will continue for the foreseeable future.

In the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, the Company disclosed that there was substantial doubt about its ability to continue as a going concern as a result of conditions that existed as of the date of issuance of the consolidated financial statements included therein. At that time, primarily as a result of the increased and costly efforts to prepare for potential commercialization of VOWST, in conjunction with the Company's research and development efforts for other preclinical and product candidates, the Company determined that it would need additional funding in early 2024. Because certain elements of management's plans to mitigate the conditions that raised substantial doubt about the Company’s ability to continue as a going concern were contingent upon the approval by the FDA of the Biologics License Application ("BLA") for VOWST, and such approval was outside the Company's control, those elements could not be considered probable according to Accounting Standards Codification (“ASC”) 205-40, Going Concern ("ASC 205-40"), and therefore also could not be considered in the evaluation of mitigating factors.

In May 2023, after FDA approval of VOWST, the Company received a $125,000 milestone payment under its license agreement with Nestlé executed in July 2021 (“2021 License Agreement,” see Note 12, Revenue from Contracts with Customers). Additionally, the Company is eligible to receive payments from Nestlé for the supply of VOWST, and is entitled to share equally in its commercial profits and losses.

As of the date of issuance of these condensed consolidated financial statements, management’s plans to mitigate the conditions that raised substantial doubt about the Company’s ability to continue as a going concern include receipt of payments from Nestlé for the supply of VOWST, and sharing equally in commercial profits and losses with Nestlé pursuant to the 2021 License Agreement. Management concluded these plans are probable of being effectively implemented and of mitigating the conditions that raised substantial doubt about the Company’s ability to continue as a going concern. The Company expects that its cash and cash equivalents as of June 30, 2023 will be sufficient to fund its operating expenses, capital expenditure requirements, and debt service obligations for at least the next 12 months from issuance of these condensed consolidated financial statements. The Company may seek to raise additional capital through financing or other transactions, including through at the market equity offerings. The future viability of the Company beyond 12 months from issuance of these condensed consolidated financial statements is dependent on its ability to raise additional capital to finance its operations.

Unaudited Interim Financial Information

The accompanying unaudited condensed consolidated financial statements as of June 30, 2023 and for the three and six months ended June 30, 2023 and 2022 have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited condensed consolidated financial statements and the notes thereto for the year ended December 31, 2022 included in the Company’s annual report on Form 10-K for the fiscal year ended December 31, 2022, which was filed with the SEC on March 7, 2023 (the “Annual Report”).

The unaudited condensed consolidated interim financial statements have been prepared on the same basis as the audited consolidated financial statements. The condensed consolidated balance sheet at December 31, 2022 was derived from audited annual financial statements, but does not contain all of the footnote disclosures from the annual financial statements. In the opinion of management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments which are necessary for a fair statement of the Company’s financial position, results of operations, and cash flows for the periods presented. Such adjustments are of a normal and recurring nature. The results of operations for the three and six months ended June 30, 2023 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2023.