Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The Company’s fiscal year ends on March 31, and its first three fiscal quarters end on June 30, September 30 and December 31. The Company has determined that it has one operating and reporting segment as it allocates resources and assesses financial performance on a consolidated basis. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. In the opinion of management, the accompanying unaudited condensed consolidated financial statements included in this Quarterly Report on Form 10-Q (“Quarterly Report”) reflect all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation of the Company’s condensed consolidated balance sheets as of December 31, 2022 and March 31, 2022, and its condensed consolidated statements of operations and comprehensive loss, and shareholders’ deficit for the three and nine months ended December 31, 2022 and 2021, and its condensed consolidated statements of cash flows for the nine months ended December 31, 2022 and 2021. The March 31, 2022 condensed consolidated balance sheet was derived from audited consolidated financial statements, but does not include all disclosures required by U.S. GAAP. The results for interim periods are not necessarily indicative of results for the entire fiscal year or any other interim period. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the Company’s previously filed audited consolidated financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K (“Annual Report”) for the fiscal year ended March 31, 2022, filed with the U.S. Securities and Exchange Commission (the “SEC”) on May 11, 2022. Any reference in these notes to applicable accounting guidance is meant to refer to the authoritative U.S. GAAP included in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”), issued by the Financial Accounting Standards Board (“FASB”). The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Dollar amounts reported in millions within this Quarterly Report are computed based on the amounts in thousands, and therefore, the sum of components may not equal the total amount reported in millions due to rounding.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the condensed consolidated financial statements and the accompanying notes, and the reported amounts of revenue and expenses during the reported periods. Actual results could differ materially from those estimates. On an ongoing basis, the Company’s management evaluates its estimates, including those related to valuation of inventories, impairment testing for long-lived-assets, variables used in calculating the fair value of the Company’s equity awards, expected achievement of performance-based vesting criteria for equity awards, variable consideration and other relevant inputs impacting the gross and net revenue recognition, contingent liabilities, recoverability of deferred tax assets, determination of lease term, research and development (“R&D”) expenses and accruals, and effective income tax rates. Management bases estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period, that are not readily apparent from other sources. Estimates and assumptions are periodically reviewed considering changes in circumstances, facts, or experience. Changes in estimates and assumptions are reflected in reported results in the period in which they become known. In addition, management’s assessment of the Company’s ability to continue as a going concern involves the estimation of the amount and timing of future cash inflows and outflows.
Liquidity and Capital Resources	Liquidity and Capital Resources As of December 31, 2022, the Company had approximately $274.4 million in cash, cash equivalents, and marketable securities. The Company believes that its existing cash, cash equivalents, marketable securities and expected cash flows to be generated from product sales will be sufficient to fund its anticipated operating expenses and capital expenditure requirements for at least the next 12 months from the date of issuance of this Quarterly Report. In future periods, if the Company’s cash, cash equivalents, marketable securities, and amounts that it expects to generate from product sales and/or third-party collaboration payments are not sufficient to enable the Company to fund its operations, the Company may need to raise additional funds in the form of equity, debt, or from other sources. There can be no assurances that such funding sources will be available at terms acceptable to the Company, or at all. If the Company has insufficient funding to meet its working capital needs, it could be required to delay, limit, reduce, or terminate its drug development programs, commercialization efforts, and/or limit or cease operations. As of December 31, 2022, the Company’s subsidiary, Myovant Sciences GmbH (“MSG”), had approximately $41.3 million of borrowing capacity available to it under the Sumitomo Pharma Loan Agreement (see Note 5(C)). As of December 31, 2022, the Company is also eligible to earn up to $3.5 billion, $85.5 million, and $118.2 million of additional milestone payments from Pfizer Inc. (“Pfizer”), Accord Healthcare, Ltd. (“Accord”), and Gedeon Richter Plc. (“Richter”), respectively, as well as potential royalty payments from Accord and Richter. See Note 8 for additional information about the Pfizer Collaboration and License Agreement, the Accord License Agreement, and the Richter Development and Commercialization Agreement.
Net Loss per Common Share	Net Loss per Common Share Basic net loss per common share is computed by dividing net loss available to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share is computed by dividing net loss by the weighted-average number of common shares and potentially dilutive shares of common stock outstanding during the period. Potential dilutive securities outstanding include stock options, restricted stock units, performance stock units, and warrants. During all periods presented, the Company incurred net losses. Accordingly, the effect of any common share equivalents would have been anti-dilutive during those periods and are not included in the calculation of diluted weighted-average number of common shares outstanding. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per common share for the periods indicated because their inclusion would have been anti-dilutive:
Recently Adopted and Issued Accounting Standards	Recently Issued Accounting Standards Not Yet Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. These amendments apply only to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of reference rate reform. The amendments are effective prospectively for all entities as of March 12, 2020 through December 31, 2022, and subject to a proposed extension to December 31, 2024. The outstanding debt with Sumitomo Pharma under the Sumitomo Pharma Loan Agreement bears a variable interest rate that is indexed off of 3-month LIBOR, for which publication is expected to be discontinued on June 30, 2023. In the event that 3-month LIBOR becomes unavailable, the Company’s subsidiary, MSG, and Sumitomo Pharma will negotiate in good faith to select an alternative interest rate in accordance with the Sumitomo Pharma Loan Agreement. The Company has not yet adopted this guidance and is currently evaluating the potential impact the adoption of this standard will have on its consolidated financial statements and related disclosures. In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss model that requires the use of forward-looking information to calculate credit loss estimates. It also eliminates the concept of other-than-temporary impairment and requires credit losses on available-for-sale debt securities to be recorded through an allowance for credit losses instead of as a reduction in the amortized cost basis of the securities. ASU 2016-13 was effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2019. Early adoption was permitted, including adoption in any interim period. In February 2020, the FASB issued ASU 2020-02, Financial Instruments-Credit Losses (Topic 326) and Leases (Topic 842) - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 119 and Update to SEC Section on Effective Date Related to Accounting Standards Update No. 2016-02, Leases (Topic 842), which amended the effective date of the original pronouncement for smaller reporting companies. ASC 2016-13 and its amendments will be effective for annual and interim periods beginning after December 15, 2022 for smaller reporting companies. The Company is currently assessing the impact the adoption of this new standard will have on its consolidated financial statements and related disclosures.

Organization and Summary of Significant Accounting Policies (Policies)

9 Months Ended

Dec. 31, 2022

Basis of Presentation and Principles of Consolidation

The Company’s fiscal year ends on March 31, and its first three fiscal quarters end on June 30, September 30 and December 31. The Company has determined that it has one operating and reporting segment as it allocates resources and assesses financial performance on a consolidated basis.

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements.

In the opinion of management, the accompanying unaudited condensed consolidated financial statements included in this Quarterly Report on Form 10-Q (“Quarterly Report”) reflect all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation of the Company’s condensed consolidated balance sheets as of December 31, 2022 and March 31, 2022, and its condensed consolidated statements of operations and comprehensive loss, and shareholders’ deficit for the three and nine months ended December 31, 2022 and 2021, and its condensed consolidated statements of cash flows for the nine months ended December 31, 2022 and 2021. The March 31, 2022 condensed consolidated balance sheet was derived from audited consolidated financial statements, but does not include all disclosures required by U.S. GAAP. The results for interim periods are not necessarily indicative of results for the entire fiscal year or any other interim period. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the Company’s previously filed audited consolidated financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K (“Annual Report”) for the fiscal year ended March 31, 2022, filed with the U.S. Securities and Exchange Commission (the “SEC”) on May 11, 2022.

Any reference in these notes to applicable accounting guidance is meant to refer to the authoritative U.S. GAAP included in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”), issued by the Financial Accounting Standards Board (“FASB”). The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Dollar amounts reported in millions within this Quarterly Report are computed based on the amounts in thousands, and therefore, the sum of components may not equal the total amount reported in millions due to rounding.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the condensed consolidated financial statements and the accompanying notes, and the reported amounts of revenue and expenses during the reported periods. Actual results could differ materially from those estimates.

On an ongoing basis, the Company’s management evaluates its estimates, including those related to valuation of inventories, impairment testing for long-lived-assets, variables used in calculating the fair value of the Company’s equity awards, expected achievement of performance-based vesting criteria for equity awards, variable consideration and other relevant inputs impacting the gross and net revenue recognition, contingent liabilities, recoverability of deferred tax assets, determination of lease term, research and development (“R&D”) expenses and accruals, and effective income tax rates. Management bases estimates on historical experience and on various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period, that are not readily apparent from other sources. Estimates and assumptions are periodically reviewed considering changes in circumstances, facts, or experience. Changes in estimates and assumptions are reflected in reported results in the period in which they become known. In addition, management’s assessment of the Company’s ability to continue as a going concern involves the estimation of the amount and timing of future cash inflows and outflows.

Liquidity and Capital Resources

As of December 31, 2022, the Company had approximately $274.4 million in cash, cash equivalents, and marketable securities. The Company believes that its existing cash, cash equivalents, marketable securities and expected cash flows to be generated from product sales will be sufficient to fund its anticipated operating expenses and capital expenditure requirements for at least the next 12 months from the date of issuance of this Quarterly Report.

In future periods, if the Company’s cash, cash equivalents, marketable securities, and amounts that it expects to generate from product sales and/or third-party collaboration payments are not sufficient to enable the Company to fund its operations, the Company may need to raise additional funds in the form of equity, debt, or from other sources. There can be no assurances that such funding sources will be available at terms acceptable to the Company, or at all. If the Company has insufficient funding to meet its working capital needs, it could be required to delay, limit, reduce, or terminate its drug development programs, commercialization efforts, and/or limit or cease operations.

As of December 31, 2022, the Company’s subsidiary, Myovant Sciences GmbH (“MSG”), had approximately $41.3 million of borrowing capacity available to it under the Sumitomo Pharma Loan Agreement (see Note 5(C)). As of December 31, 2022, the Company is also eligible to earn up to $3.5 billion, $85.5 million, and $118.2 million of additional milestone payments from Pfizer Inc. (“Pfizer”), Accord Healthcare, Ltd. (“Accord”), and Gedeon Richter Plc. (“Richter”), respectively, as well as potential royalty payments from Accord and Richter. See Note 8 for additional information about the Pfizer Collaboration and License Agreement, the Accord License Agreement, and the Richter Development and Commercialization Agreement.

Net Loss per Common Share

Basic net loss per common share is computed by dividing net loss available to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share is computed by dividing net loss by the weighted-average number of common shares and potentially dilutive shares of common stock outstanding during the period. Potential dilutive securities outstanding include stock options, restricted stock units, performance stock units, and warrants. During all periods presented, the Company incurred net losses. Accordingly, the effect of any common share equivalents would have been anti-dilutive during those periods and are not included in the calculation of diluted weighted-average number of common shares outstanding.

The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per common share for the periods indicated because their inclusion would have been anti-dilutive:

Recently Adopted and Issued Accounting Standards

Recently Issued Accounting Standards Not Yet Adopted

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. These amendments apply only to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate expected to be discontinued because of reference rate reform. The amendments are effective prospectively for all entities as of March 12, 2020 through December 31, 2022, and subject to a proposed extension to December 31, 2024. The outstanding debt with Sumitomo Pharma under the Sumitomo Pharma Loan Agreement bears a variable interest rate that is indexed off of 3-month LIBOR, for which publication is expected to be discontinued on June 30, 2023. In the event that 3-month LIBOR becomes unavailable, the Company’s subsidiary, MSG, and Sumitomo Pharma will negotiate in good faith to select an alternative interest rate in accordance with the Sumitomo Pharma Loan Agreement. The Company has not yet adopted this guidance and is currently evaluating the potential impact the adoption of this standard will have on its consolidated financial statements and related disclosures.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss model that requires the use of forward-looking information to calculate credit loss estimates. It also eliminates the concept of other-than-temporary impairment and requires credit losses on available-for-sale debt securities to be recorded through an allowance for credit losses instead of as a reduction in the amortized cost basis of the securities. ASU 2016-13 was effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2019. Early adoption was permitted, including adoption in any interim period. In February 2020, the FASB issued ASU 2020-02, Financial Instruments-Credit Losses (Topic 326) and Leases (Topic 842) - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting

Bulletin No. 119 and Update to SEC Section on Effective Date Related to Accounting Standards Update No. 2016-02, Leases (Topic 842), which amended the effective date of the original pronouncement for smaller reporting companies. ASC 2016-13 and its amendments will be effective for annual and interim periods beginning after December 15, 2022 for smaller reporting companies. The Company is currently assessing the impact the adoption of this new standard will have on its consolidated financial statements and related disclosures.