Organization and Accounting Pronouncements	9 Months Ended
Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Accounting Pronouncements	1. Organization and Accounting Pronouncements Description of Business Equillium, Inc. (the Company) was incorporated in the state of Delaware on March 16, 2017. The Company is a clinical-stage biotechnology company leveraging deep understanding of immunology to develop novel products to treat severe autoimmune and inflammatory disorders with high unmet medical need. From inception through September 30, 2020, the Company has devoted substantially all of its efforts to organizing and staffing the Company, business planning, raising capital, in-licensing rights to itolizumab (EQ001), conducting preclinical research, filing three initial Investigational New Drug applications (INDs), commencing clinical development of the Company’s initial product candidate, itolizumab (EQ001), conducting business development activities, and the general and administrative activities associated with operating as a public company. In addition, the Company has a limited operating history, has not generated revenues from its principal operations, and the sales and income potential of its business is unproven. Liquidity and Business Risks As of September 30, 2020, the Company had $90.5 million in cash, cash equivalents and short-term investments. The Company has incurred significant operating losses and negative cash flows from operations. The Company expects to use its cash, cash equivalents and short-term investments to fund research and development of itolizumab (EQ001) and for working capital and other general corporate purposes. The Company does not expect to generate any revenues from product sales unless and until the Company successfully completes development and obtains regulatory approval of itolizumab (EQ001) or any future product candidate, which is unlikely to happen within the next 12 months, if ever. Accordingly, until such time as the Company can generate significant revenue from sales of its product candidates, if ever, the Company expects to finance its cash needs through a combination of equity offerings, debt financings, and collaboration and license agreements. However, the Company may not be able to secure additional financing or enter into such other arrangements in a timely manner or on favorable terms, if at all. As a result of the COVID-19 pandemic and actions taken to slow its spread, the global credit and financial markets have experienced extreme volatility, including diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, increases in unemployment rates and uncertainty about economic stability. There can be no assurance that further deterioration in credit and financial markets and confidence in economic conditions will not occur. If equity and credit markets deteriorate, it may make any necessary debt or equity financing more difficult to obtain, more costly and/or more dilutive. The Company’s failure to raise capital or enter into such other arrangements when needed would have a negative impact on the Company’s financial condition and could force the Company to delay, reduce or terminate its research and development programs or other operations, or grant rights to develop and market product candidates that the Company would otherwise prefer to develop and market itself. Management believes that the Company’s cash, cash equivalents and short-term investments as of September 30, 2020 will be sufficient to fund operations for at least the next 12 months from the date this Quarterly Report on Form 10-Q is filed with the Securities and Exchange Commission (SEC). In March 2020, as a result of impacts and risks associated with the COVID-19 pandemic, the Company decided to pause enrollment in its Phase 1b clinical trials of itolizumab (EQ001) in uncontrolled asthma and lupus nephritis. This decision was not based on any observed safety issues associated with itolizumab (EQ001) but rather out of an abundance of caution related to the COVID-19 pandemic and the Company’s concern for the well-being of patients and their caregivers. In July 2020, the Company announced that patient enrollment in both of those trials had resumed. The Company did not pause enrollment of patients in the Phase 1b/2 clinical trial of itolizumab (EQ001) for the treatment of acute graft-versus-host disease (aGVHD) given the acute life-threatening severity of the disease, as the Company believes itolizumab (EQ001) represents a potentially life-saving treatment for these severely ill patients. However, there remains a risk that enrollment of that trial, as well as enrollment in the Company’s recently announced trial to evaluate itolizumab in hospitalized COVID-19 patients suffering from acute respiratory distress syndrome and the recently resumed Phase 1b trials in uncontrolled asthma and lupus nephritis, in addition to the timing of topline data from all four of those trials may also be adversely impacted by the COVID-19 pandemic. The COVID-19 outbreak in the United States and the rest of the world has caused disruptions to the Company’s business, which may delay results of the Company’s clinical trials and adversely impact the Company’s business. The Company cannot predict how legal and regulatory responses to concerns about COVID-19 or other major public health issues will impact the Company’s business, nor can it predict potential adverse impacts related to the availability of capital to fund the Company’s operations. Additionally, the Company’s workforce and outside consultants may also be affected, which could result in an adverse impact on the Company’s ability to conduct business. Any of these factors, alone or in combination with others, could harm the Company’s business, results of operations, financial condition or liquidity. However, the magnitude, timing, and duration of any such potential financial impacts cannot be reasonably estimated at this time. Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and the rules and regulations of the SEC related to a quarterly report on Form 10-Q. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Updates (ASU) promulgated by the Financial Accounting Standards Board (FASB). Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. The condensed consolidated financial statements reflect all adjustments which, in the opinion of management, are necessary for a fair statement of the results for the periods presented. All such adjustments are of a normal and recurring nature. The operating results presented in these condensed consolidated financial statements are not necessarily indicative of the results that may be expected for any future periods. These condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2019 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 26, 2020. Principles of Consolidation In January 2019, the Company created a new wholly-owned subsidiary in Australia with the Company serving as the sole shareholder through the subscription of shares. The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All intercompany transactions and balances have been eliminated in consolidation. Foreign Currency Translation The Company’s wholly-owned subsidiary in Australia uses their local currency to be their functional currency. Assets and liabilities are translated into U.S. dollars at quarter-end exchange rates and revenues and expenses are translated at average exchange rates during the quarter and year-to-date periods. Foreign currency translation adjustments for the reported periods are included in accumulated other comprehensive income in the Company’s condensed consolidated statements of comprehensive loss, and the cumulative effect is included in the stockholders’ equity section of the Company’s condensed consolidated balance sheets. Realized and unrealized gains and losses denominated in foreign currencies are recorded in operating expenses in the Company’s condensed consolidated statements of operations. For both the three and nine months ended September 30, 2020, net realized and unrealized gains totaled $0.1 million. For the three and nine months ended September 30, 2019, net realized and unrealized losses totaled $12,000 and $17,000, respectively. Recently Issued Accounting Pronouncements In February 2015, the FASB issued ASU 2016-02, Leases (Topic 842), which amends the FASB ASC 840 and creates Topic 842, Leases. The new topic supersedes Topic 840, Leases, and increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requires disclosures of key information about leasing arrangements. For companies that are not emerging growth companies (EGCs), ASU 2016-02 is effective for fiscal years beginning after December 15, 2018. For EGCs, the ASU was to be effective for fiscal years beginning after December 15, 2019. However, in November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842), Effective Dates (ASU 2019-10), which included a one-year deferral of the effective date of ASU 2016-02 for certain entities. As a result, the ASU is now effective for EGCs for fiscal years beginning after December 15, 2020, and interim periods within fiscal years beginning after December 15, 2021. The Company expects to adopt the new standard in the fourth quarter of 2021 using the modified retrospective method, under which the Company will apply Topic 842 to existing and new leases as of January 1, 2021, but prior periods will not be restated and will continue to be reported under Topic 840 guidance in effect during those periods. The Company anticipates that the adoption will not have a material impact on its condensed consolidated statements of operations and condensed consolidated comprehensive loss or its condensed consolidated statements of cash flows but expects to recognize right-of-use assets and liabilities for lease obligations associated with its operating leases. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) – Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which is designed to improve the effectiveness of disclosures by removing, modifying and adding disclosures related to fair value measurements. ASU 2018-13 was effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption was permitted. The Company adopted this ASU on January 1, 2020. The adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements.

Organization and Accounting Pronouncements

9 Months Ended

Sep. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Organization and Accounting Pronouncements

1. Organization and Accounting Pronouncements

Description of Business

Equillium, Inc. (the Company) was incorporated in the state of Delaware on March 16, 2017. The Company is a clinical-stage biotechnology company leveraging deep understanding of immunology to develop novel products to treat severe autoimmune and inflammatory disorders with high unmet medical need.

From inception through September 30, 2020, the Company has devoted substantially all of its efforts to organizing and staffing the Company, business planning, raising capital, in-licensing rights to itolizumab (EQ001), conducting preclinical research, filing three initial Investigational New Drug applications (INDs), commencing clinical development of the Company’s initial product candidate, itolizumab (EQ001), conducting business development activities, and the general and administrative activities associated with operating as a public company. In addition, the Company has a limited operating history, has not generated revenues from its principal operations, and the sales and income potential of its business is unproven.

Liquidity and Business Risks

As of September 30, 2020, the Company had $90.5 million in cash, cash equivalents and short-term investments. The Company has incurred significant operating losses and negative cash flows from operations. The Company expects to use its cash, cash equivalents and short-term investments to fund research and development of itolizumab (EQ001) and for working capital and other general corporate purposes. The Company does not expect to generate any revenues from product sales unless and until the Company successfully completes development and obtains regulatory approval of itolizumab (EQ001) or any future product candidate, which is unlikely to happen within the next 12 months, if ever. Accordingly, until such time as the Company can generate significant revenue from sales of its product candidates, if ever, the Company expects to finance its cash needs through a combination of equity offerings, debt financings, and collaboration and license agreements. However, the Company may not be able to secure additional financing or enter into such other arrangements in a timely manner or on favorable terms, if at all. As a result of the COVID-19 pandemic and actions taken to slow its spread, the global credit and financial markets have experienced extreme volatility, including diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, increases in unemployment rates and uncertainty about economic stability. There can be no assurance that further deterioration in credit and financial markets and confidence in economic conditions will not occur. If equity and credit markets deteriorate, it may make any necessary debt or equity financing more difficult to obtain, more costly and/or more dilutive. The Company’s failure to raise capital or enter into such other arrangements when needed would have a negative impact on the Company’s financial condition and could force the Company to delay, reduce or terminate its research and development programs or other operations, or grant rights to develop and market product candidates that the Company would otherwise prefer to develop and market itself. Management believes that the Company’s cash, cash equivalents and short-term investments as of September 30, 2020 will be sufficient to fund operations for at least the next 12 months from the date this Quarterly Report on Form 10-Q is filed with the Securities and Exchange Commission (SEC).

In March 2020, as a result of impacts and risks associated with the COVID-19 pandemic, the Company decided to pause enrollment in its Phase 1b clinical trials of itolizumab (EQ001) in uncontrolled asthma and lupus nephritis. This decision was not based on any observed safety issues associated with itolizumab (EQ001) but rather out of an abundance of caution related to the COVID-19 pandemic and the Company’s concern for the well-being of patients and their caregivers. In July 2020, the Company announced that patient enrollment in both of those trials had resumed. The Company did not pause enrollment of patients in the Phase 1b/2 clinical trial of itolizumab (EQ001) for the treatment of acute graft-versus-host disease (aGVHD) given the acute life-threatening severity of the disease, as the Company believes itolizumab (EQ001) represents a potentially life-saving treatment for these severely ill patients. However, there remains a risk that enrollment of that trial, as well as enrollment in the Company’s recently announced trial to evaluate itolizumab in hospitalized COVID-19 patients suffering from acute respiratory distress syndrome and the recently resumed Phase 1b trials in uncontrolled asthma and lupus nephritis, in addition to the timing of topline data from all four of those trials may also be adversely impacted by the COVID-19 pandemic.

The COVID-19 outbreak in the United States and the rest of the world has caused disruptions to the Company’s business, which may delay results of the Company’s clinical trials and adversely impact the Company’s business. The Company cannot predict how legal and regulatory responses to concerns about COVID-19 or other major public health issues will impact the Company’s business, nor can it predict potential adverse impacts related to the availability of capital to fund the Company’s operations. Additionally, the Company’s workforce and outside consultants may also be affected, which could result in an adverse impact on the Company’s ability to conduct business. Any of these factors, alone or in combination with others, could harm the Company’s business, results of operations, financial condition or liquidity. However, the magnitude, timing, and duration of any such potential financial impacts cannot be reasonably estimated at this time.

Basis of Presentation

The accompanying condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and the rules and regulations of the SEC related to a quarterly report on Form 10-Q. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Updates (ASU) promulgated by the Financial Accounting Standards Board (FASB). Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. The condensed consolidated financial statements reflect all adjustments which, in the opinion of management, are necessary for a fair statement of the results for the periods presented. All such adjustments are of a normal and recurring nature. The operating results presented in these condensed consolidated financial statements are not necessarily indicative of the results that may be expected for any future periods. These condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2019 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 26, 2020.

Principles of Consolidation

In January 2019, the Company created a new wholly-owned subsidiary in Australia with the Company serving as the sole shareholder through the subscription of shares. The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All intercompany transactions and balances have been eliminated in consolidation.

Foreign Currency Translation

The Company’s wholly-owned subsidiary in Australia uses their local currency to be their functional currency. Assets and liabilities are translated into U.S. dollars at quarter-end exchange rates and revenues and expenses are translated at average exchange rates during the quarter and year-to-date periods. Foreign currency translation adjustments for the reported periods are included in accumulated other comprehensive income in the Company’s condensed consolidated statements of comprehensive loss, and the cumulative effect is included in the stockholders’ equity section of the Company’s condensed consolidated balance sheets. Realized and unrealized gains and losses denominated in foreign currencies are recorded in operating expenses in the Company’s condensed consolidated statements of operations. For both the three and nine months ended September 30, 2020, net realized and unrealized gains totaled $0.1 million. For the three and nine months ended September 30, 2019, net realized and unrealized losses totaled $12,000 and $17,000, respectively.

Recently Issued Accounting Pronouncements

In February 2015, the FASB issued ASU 2016-02, Leases (Topic 842), which amends the FASB ASC 840 and creates Topic 842, Leases. The new topic supersedes Topic 840, Leases, and increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requires disclosures of key information about leasing arrangements. For companies that are not emerging growth companies (EGCs), ASU 2016-02 is effective for fiscal years beginning after December 15, 2018. For EGCs, the ASU was to be effective for fiscal years beginning after December 15, 2019. However, in November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815) and Leases (Topic 842), Effective Dates (ASU 2019-10), which included a one-year deferral of the effective date of ASU 2016-02 for certain entities. As a result, the ASU is now effective for EGCs for fiscal years beginning after December 15, 2020, and interim periods within fiscal years beginning after December 15, 2021. The Company expects to adopt the new standard in the fourth quarter of 2021 using the modified retrospective method, under which the Company will apply Topic 842 to existing and new leases as of January 1, 2021, but prior periods will not be restated and will continue to be reported under Topic 840 guidance in effect during those periods. The Company anticipates that the adoption will not have a material impact on its condensed consolidated statements of operations and condensed consolidated comprehensive loss or its condensed consolidated statements of cash flows but expects to recognize right-of-use assets and liabilities for lease obligations associated with its operating leases.

In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) – Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which is designed to improve the effectiveness of disclosures by removing, modifying and adding disclosures related to fair value measurements. ASU 2018-13 was effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption was permitted. The Company adopted this ASU on January 1, 2020. The adoption of this standard did not have a material impact on the Company’s condensed consolidated financial statements.