Summary of significant accounting policies (Policies)	3 Months Ended
Mar. 31, 2021
Summary of significant accounting policies
Basis of consolidation	a) Basis of consolidation The consolidated financial statements include the accounts of the Company and Milestone Pharmaceuticals USA, Inc. All intercompany transactions and balances have been eliminated.
Basis of presentation and use of accounting estimates	b) Basis of presentation and use of accounting estimates These unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (US GAAP) and on a basis consistent with those accounting principles followed by the Company and disclosed in note 2 of its most recent annual consolidated financial statements. Certain information, in particular the accompanying notes normally included in the annual financial statements prepared in accordance with US GAAP have been omitted or condensed. Accordingly, the unaudited interim condensed consolidated financial statements do not include all the information required for full annual financial statements, and therefore, should be read in conjunction with the annual consolidated financial statements and the notes thereto for the year ended December 31, 2020. In the opinion of the Company's management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments, consisting of only normal recurring adjustments, necessary for a fair statement of its balance sheet as of March 31, 2021, and its statements of loss and comprehensive loss, shareholders’ equity and of cash flows for the three months ended March 31, 2021 and 2020. The condensed consolidated balance sheet as of December 31, 2020, was derived from audited annual consolidated financial statements, but does not contain all of the footnote disclosures required by accounting principles generally accepted in the United States of America. These unaudited interim condensed consolidated financial statements are presented in US dollars, which is the Company’s functional currency. The preparation of unaudited interim condensed consolidated financial statements with US GAAP requires the Company to make estimates and judgments that affect certain reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited interim condensed consolidated financial statements and the reported amounts of revenue and expenses during the period. The Company bases its estimates and assumptions on current facts, historical experience and various other factors that it believes are reasonable under the circumstances, to determine the carrying values of assets and liabilities that are not readily apparent from other sources. Significant estimates and judgments include, but are not limited to, research and development tax credits recoverable, progress of activities performed by the CROs and CMOs which are used to calculate the research and development expense incurred, and share-based compensation. Accordingly, actual results may differ from those estimates and such differences may be material.
Significant Risks and Uncertainties	c) Significant Risks and Uncertainties The COVID-19 pandemic has had an impact on our business, operations and clinical development timelines. Government orders and restrictions in order to control the spread of the disease have impacted patient recruitment, enrollment and follow-up visits at clinical sites. With the global spread of the ongoing COVID-19 pandemic, the Company has implemented business continuity plans designed to address and mitigate the impact of the COVID-19 pandemic on its business. The Company anticipates that the COVID-19 pandemic will continue to have an impact on the development timelines for its clinical programs. The extent to which the COVID-19 pandemic continues to impact its business, its clinical development and regulatory efforts, its corporate development objectives and the value of and market for its common shares will depend on future developments that remain highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, travel restrictions, quarantines, social distancing and business closure requirements in the U.S., Europe and other countries, and the effectiveness of actions taken globally to contain and treat the disease. The global economic slowdown, the overall disruption of global healthcare systems and the other risks and uncertainties associated with the pandemic could have a material adverse effect on the Company’s business, financial condition, results of operations and growth prospects. In addition, the Company is subject to other challenges and risks specific to its business and its ability to execute on its strategy, as well as risks and uncertainties common to companies in the pharmaceutical industry, including, without limitation, risks and uncertainties associated with: obtaining regulatory approval of its product candidate; delays or problems in the supply of its study drug or failure to comply with manufacturing regulations; identifying, acquiring or in-licensing product candidates; pharmaceutical product development and the inherent uncertainty of clinical success; and the challenges of protecting and enhancing its intellectual property rights; and complying with applicable regulatory requirements.
Sources of Liquidity and Funding Requirements	d) Sources of Liquidity and Funding Requirements Since inception, the Company incurred significant operating losses. Prior to May 2019, the Company financed its operations primarily through sales of convertible preferred shares to accredited investors generating net proceeds of $138.8 million. In May 2019, the Company received net proceeds of $85.4 million from its Initial Public Offering (IPO). In July 2020, the Company received $24.8 million of net proceeds from the private placement of pre-funded warrants to existing shareholders. In October 2020, the Company concluded an offering of common shares and pre-funded warrants for net proceeds of $48.2 million. The Company has incurred operating losses and experienced negative operating cash flows since its inception and anticipates to continue to incur losses for at least the next several years. As of March 31, 2021, the Company had cash, cash equivalents and short-term investments of $129.9 million and an accumulated deficit of $176.0 million.

Summary of significant accounting policies (Policies)

3 Months Ended

Mar. 31, 2021

Summary of significant accounting policies

a) Basis of consolidation

The consolidated financial statements include the accounts of the Company and Milestone Pharmaceuticals USA, Inc. All intercompany transactions and balances have been eliminated.

Basis of presentation and use of accounting estimates

b) Basis of presentation and use of accounting estimates

These unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (US GAAP) and on a basis consistent with those accounting principles followed by the Company and disclosed in note 2 of its most recent annual consolidated financial statements. Certain information, in particular the accompanying notes normally included in the annual financial statements prepared in accordance with US GAAP have been omitted or condensed. Accordingly, the unaudited interim condensed consolidated financial statements do not include all the information required for full annual financial statements, and therefore, should be read in conjunction with the annual consolidated financial statements and the notes thereto for the year ended December 31, 2020.

In the opinion of the Company's management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments, consisting of only normal recurring adjustments, necessary for a fair statement of its balance sheet as of March 31, 2021, and its statements of loss and comprehensive loss, shareholders’ equity and of cash flows for the three months ended March 31, 2021 and 2020.

The condensed consolidated balance sheet as of December 31, 2020, was derived from audited annual consolidated financial statements, but does not contain all of the footnote disclosures required by accounting principles generally accepted in the United States of America.

These unaudited interim condensed consolidated financial statements are presented in US dollars, which is the Company’s functional currency.

The preparation of unaudited interim condensed consolidated financial statements with US GAAP requires the Company to make estimates and judgments that affect certain reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited interim condensed consolidated financial statements and the reported amounts of revenue and expenses during the period. The Company bases its estimates and assumptions on current facts, historical experience and various other factors that it believes are reasonable under the circumstances, to determine the carrying values of assets and liabilities that are not readily apparent from other sources. Significant estimates and judgments include, but are not limited to, research and development tax credits recoverable, progress of activities performed by the CROs and CMOs which are used to calculate the research and development expense incurred, and share-based compensation. Accordingly, actual results may differ from those estimates and such differences may be material.

Significant Risks and Uncertainties

c) Significant Risks and Uncertainties

The COVID-19 pandemic has had an impact on our business, operations and clinical development timelines. Government orders and restrictions in order to control the spread of the disease have impacted patient recruitment, enrollment and follow-up visits at clinical sites. With the global spread of the ongoing COVID-19 pandemic, the Company has implemented business continuity plans designed to address and mitigate the impact of the COVID-19 pandemic on its business. The Company anticipates that the COVID-19 pandemic will continue to have an impact on the development timelines for its clinical programs. The extent to which the COVID-19 pandemic continues to impact its business, its clinical development and regulatory efforts, its corporate development objectives and the value of and market for its common shares will depend on future developments that remain highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, travel restrictions, quarantines, social distancing and business closure requirements in the U.S., Europe and other countries, and the effectiveness of actions taken globally to contain and treat the disease. The global economic slowdown, the overall disruption of global healthcare systems and the other risks and uncertainties associated with the pandemic could have a material adverse effect on the Company’s business, financial condition, results of operations and growth prospects.

In addition, the Company is subject to other challenges and risks specific to its business and its ability to execute on its strategy, as well as risks and uncertainties common to companies in the pharmaceutical industry, including, without limitation, risks and uncertainties associated with: obtaining regulatory approval of its product candidate; delays or problems in the supply of its study drug or failure to comply with manufacturing regulations; identifying, acquiring or in-licensing product candidates; pharmaceutical product development and the inherent uncertainty of clinical success; and the challenges of protecting and enhancing its intellectual property rights; and complying with applicable regulatory requirements.

Sources of Liquidity and Funding Requirements

d) Sources of Liquidity and Funding Requirements

Since inception, the Company incurred significant operating losses. Prior to May 2019, the Company financed its operations primarily through sales of convertible preferred shares to accredited investors generating net proceeds of $138.8 million. In May 2019, the Company received net proceeds of $85.4 million from its Initial Public Offering (IPO). In July 2020, the Company received $24.8 million of net proceeds from the private placement of pre-funded warrants to existing shareholders. In October 2020, the Company concluded an offering of common shares and pre-funded warrants for net proceeds of $48.2 million.

The Company has incurred operating losses and experienced negative operating cash flows since its inception and anticipates to continue to incur losses for at least the next several years. As of March 31, 2021, the Company had cash, cash equivalents and short-term investments of $129.9 million and an accumulated deficit of $176.0 million.