Nature of Business	6 Months Ended
Jun. 30, 2020
Disclosure Text Block [Abstract]
Nature of Business	Note 1. Nature of business Description of business iTeos Therapeutics, Inc. (iTeos Inc. or the Company), a Delaware corporation headquartered in Cambridge, Massachusetts (incorporated on October 4, 2019), is the successor to iTeos Belgium SA (iTeos Belgium) a company organized under the laws of Belgium in 2011 and headquartered in Charleroi, Belgium. The Company is a clinical stage biopharmaceutical company that focuses on developing cancer immunotherapies by targeting key mechanisms of immunosuppression in the tumor microenvironment. The most advanced clinical program is EOS-850, a small molecule antagonist of the A_2AR, which is currently in an open-label Phase 1/2a clinical trial in adult patients. The second clinical program is EOS-448, an antibody directed to TIGIT, which entered a Phase 1/2a clinical trial in February 2020. The Company also has a preclinical pipeline targeting additional mechanisms. Corporate reorganization On October 4, 2019, the Company completed a corporate reorganization in which iTeos Inc., iTeos Belgium, and the stockholders of iTeos Belgium entered into an Equity Contribution and Exchange Agreement (Share Exchange), pursuant to which all outstanding shares of preferred stock, common stock and profit certificates of iTeos Belgium were exchanged on a one-for-one basis for newly issued shares of iTeos Inc. iTeos Inc. was a newly-formed holding company, and as a result of the Share Exchange, iTeos Belgium became a wholly owned subsidiary of iTeos Inc. iTeos Therapeutics U.S. Inc. (iTeos U.S.) included the Company’s U.S. operations and was located in Cambridge, Massachusetts. iTeos U.S., which was a wholly owned subsidiary of iTeos Belgium prior to the Share Exchange, continued to be a wholly owned subsidiary of iTeos Belgium throughout 2019. On February 28, 2020, iTeos Inc. purchased iTeos U.S. from iTeos Belgium and then the entities effectively merged. The Share Exchange was accounted for in accordance with the Financial Accounting Standards Board (FASB) Accounting Standard Codification (ASC) 805-50, Business Combinations—Related Issues. The Company evaluated the guidance in ASC 805-50 with respect to the transaction between entities under common control and concluded that since all shareholders of iTeos Inc. and iTeos Belgium have nearly identical ownership percentages and interests before and after the transaction, the Share Exchange lacks economic substance and represents a transaction between entities with common ownership and should be accounted for in a manner consistent with common control transactions and did not result in a change in control at the ultimate parent or the controlling shareholder level. Going concern Since inception, the Company’s activities have consisted primarily of performing research and development to advance its product candidates. The Company is still in the development phase and has not been marketing any developed products to-date. Through June 30, 2020, the Company has funded its operations with proceeds from sales of redeemable convertible preferred stock, collaboration and licensing agreements, grants and borrowings under various agreements with foreign public funding agencies. Since inception, the Company has incurred recurring losses, including a net loss of $12.4 million for the six months ended June 30, 2020. As of June 30, 2020, the Company had an accumulated deficit of $48.3 million. The Company expects to continue to generate operating losses in the foreseeable future. On July 28, 2020, the Company closed its initial public offering, or IPO, which generated net proceeds of $184.0 million, and on August 5, 2020, the underwriters purchased 1,505,359 additional shares of common stock under their option for net proceeds of $26.6 million after deducting underwriting discounts and commissions (see Note 12). As of September 1, 2020, the issuance date of the condensed consolidated financial statements for the six months ended June 30, 2020, the Company expected that its cash would be sufficient to fund its operating expenses, capital expenditure requirements and debt service payments through at least 12 months from the issuance date of the condensed consolidated financial statements. The Company will seek additional funding in order to reach its development and commercialization objectives. The Company will seek funds either through public debt or equity offerings or further private equity financings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. The Company may not be able to obtain funding on acceptable terms, or at all, and the Company may not be able to enter into collaborations or other arrangements. The terms of any funding may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects. The accompanying condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The condensed consolidated financial statements do not reflect any adjustments relating to the recoverability and classification of assets or the amounts and classification of liabilities that might be necessary if the Company is unable to continue as a going concern. COVID-19 In December 2019, a novel strain of coronavirus (COVID-19) emerged in Wuhan, Hubei Province, China. As of June 30, 2020, COVID-19 has spread to Europe, the United States and many other countries, and has been declared a pandemic by the World Health Organization. Efforts to contain the spread of COVID-19 have intensified. The United States, including the Commonwealth of Massachusetts where our headquarters are located, as well as countries throughout Europe and Asia have implemented severe travel restrictions, social distancing requirements and stay-at-home orders, among other restrictions, which, in some cases, have had the effect of delaying the commencement of non-COVID-19-related clinical trials. As a result, the COVID-19 pandemic has caused significant disruptions to the U.S., regional and global economies and has contributed to significant volatility and negative pressure in financial markets. The Company has been carefully monitoring the COVID-19 pandemic and its potential impact on the Company’s business and has taken important steps to help ensure the safety of employees and their families and to reduce the spread of COVID-19 in the Cambridge and Belgian communities. The Company has established a work-from-home policy for all employees, other than those performing or supporting business-critical operations, such as certain members of our laboratory and facilities staff. For those employees, we have implemented stringent safety measures designed to comply with applicable federal, state and local guidelines instituted in response to the COVID-19 pandemic. The Company has also maintained efficient communication with the Company’s partners and clinical sites as the COVID-19 situation has progressed. The Company has taken these precautionary steps while maintaining business continuity so that we can continue to progress our programs. Risk and uncertainties The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty regarding results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s current or future product candidates, uncertainty of market acceptance of the Company’s product candidates, if approved, competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals and sole source suppliers. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities and may not ultimately lead to a marketing approval and commercialization of a product. Even if the Company’s drug development efforts are successful, it is uncertain if and when the Company will realize significant revenue from product sales. The Company’s product candidates require approvals from the U.S. Food and Drug Administration (FDA) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.

Nature of Business

6 Months Ended

Jun. 30, 2020

Note 1. Nature of business

Description of business

iTeos Therapeutics, Inc. (iTeos Inc. or the Company), a Delaware corporation headquartered in Cambridge, Massachusetts (incorporated on October 4, 2019), is the successor to iTeos Belgium SA (iTeos Belgium) a company organized under the laws of Belgium in 2011 and headquartered in Charleroi, Belgium. The Company is a clinical stage biopharmaceutical company that focuses on developing cancer immunotherapies by targeting key mechanisms of immunosuppression in the tumor microenvironment. The most advanced clinical program is EOS-850, a small molecule antagonist of the A_2AR, which is currently in an open-label Phase 1/2a clinical trial in adult patients. The second clinical program is EOS-448, an antibody directed to TIGIT, which entered a Phase 1/2a clinical trial in February 2020. The Company also has a preclinical pipeline targeting additional mechanisms.

Corporate reorganization

On October 4, 2019, the Company completed a corporate reorganization in which iTeos Inc., iTeos Belgium, and the stockholders of iTeos Belgium entered into an Equity Contribution and Exchange Agreement (Share Exchange), pursuant to which all outstanding shares of preferred stock, common stock and profit certificates of iTeos Belgium were exchanged on a one-for-one basis for newly issued shares of iTeos Inc. iTeos Inc. was a newly-formed holding company, and as a result of the Share Exchange, iTeos Belgium became a wholly owned subsidiary of iTeos Inc. iTeos Therapeutics U.S. Inc. (iTeos U.S.) included the Company’s U.S. operations and was located in Cambridge, Massachusetts. iTeos U.S., which was a wholly owned subsidiary of iTeos Belgium prior to the Share Exchange, continued to be a wholly owned subsidiary of iTeos Belgium throughout 2019. On February 28, 2020, iTeos Inc. purchased iTeos U.S. from iTeos Belgium and then the entities effectively merged.

The Share Exchange was accounted for in accordance with the Financial Accounting Standards Board (FASB) Accounting Standard Codification (ASC) 805-50, Business Combinations—Related Issues. The Company evaluated the guidance in ASC 805-50 with respect to the transaction between entities under common control and concluded that since all shareholders of iTeos Inc. and iTeos Belgium have nearly identical ownership percentages and interests before and after the transaction, the Share Exchange lacks economic substance and represents a transaction between entities with common ownership and should be accounted for in a manner consistent with common control transactions and did not result in a change in control at the ultimate parent or the controlling shareholder level.

Going concern

Since inception, the Company’s activities have consisted primarily of performing research and development to advance its product candidates. The Company is still in the development phase and has not been marketing any developed products to-date. Through June 30, 2020, the Company has funded its operations with proceeds from sales of redeemable convertible preferred stock, collaboration and licensing agreements, grants and borrowings under various agreements with foreign public funding agencies. Since inception, the Company has incurred recurring losses, including a net loss of $12.4 million for the six months ended June 30, 2020. As of June 30, 2020, the Company had an accumulated deficit of $48.3 million. The Company expects to continue to generate operating losses in the foreseeable future. On July 28, 2020, the Company closed its initial public offering, or IPO, which generated net proceeds of $184.0 million, and on August 5, 2020, the underwriters purchased 1,505,359 additional shares of common stock under their option for net proceeds of $26.6 million after deducting underwriting discounts and commissions (see Note 12). As of September 1, 2020, the issuance date of the condensed consolidated financial statements for the six months ended June 30, 2020, the Company expected that its cash would be sufficient to fund its operating expenses, capital expenditure requirements and debt service payments through at least 12 months from the issuance date of the condensed consolidated financial statements.

The Company will seek additional funding in order to reach its development and commercialization objectives. The Company will seek funds either through public debt or equity offerings or further private equity financings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. The Company may not be able to obtain funding on acceptable terms, or at all, and the Company may not be able to enter into collaborations or other arrangements. The terms of any funding may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects.

The accompanying condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The condensed consolidated financial statements do not reflect any adjustments relating to the recoverability and classification of assets or the amounts and classification of liabilities that might be necessary if the Company is unable to continue as a going concern.

COVID-19

In December 2019, a novel strain of coronavirus (COVID-19) emerged in Wuhan, Hubei Province, China. As of June 30, 2020, COVID-19 has spread to Europe, the United States and many other countries, and has been declared a pandemic by the World Health Organization. Efforts to contain the spread of COVID-19 have intensified. The United States, including the Commonwealth of Massachusetts where our headquarters are located, as well as countries throughout Europe and Asia have implemented severe travel restrictions, social distancing requirements and stay-at-home orders, among other restrictions, which, in some cases, have had the effect of delaying the commencement of non-COVID-19-related clinical trials. As a result, the COVID-19 pandemic has caused significant disruptions to the U.S., regional and global economies and has contributed to significant volatility and negative pressure in financial markets.

The Company has been carefully monitoring the COVID-19 pandemic and its potential impact on the Company’s business and has taken important steps to help ensure the safety of employees and their families and to reduce the spread of COVID-19 in the Cambridge and Belgian communities. The Company has established a work-from-home policy for all employees, other than those performing or supporting business-critical operations, such as certain members of our laboratory and facilities staff. For those employees, we have implemented stringent safety measures designed to comply with applicable federal, state and local guidelines instituted in response to the COVID-19 pandemic. The Company has also maintained efficient communication with the Company’s partners and clinical sites as the COVID-19 situation has progressed. The Company has taken these precautionary steps while maintaining business continuity so that we can continue to progress our programs.

Risk and uncertainties

The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty regarding results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s current or future product candidates, uncertainty of market acceptance of the Company’s product candidates, if approved, competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals and sole source suppliers. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities and may not ultimately lead to a marketing approval and commercialization of a product. Even if the Company’s drug development efforts are successful, it is uncertain if and when the Company will realize significant revenue from product sales.

The Company’s product candidates require approvals from the U.S. Food and Drug Administration (FDA) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.