Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2020
Accounting Policies [Abstract]
Basis of presentation	(a) Basis of presentation The accompanying unaudited condensed consolidated financial statements are presented in United States (“U.S.”) dollars and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim financial information. Accordingly, these consolidated financial statements do not include all of the information and footnotes required for complete consolidated financial statements and should be read in conjunction with the audited consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, filed with the Securities and Exchange Commission on March 12, 2020. In management’s opinion, the unaudited condensed consolidated financial statements reflect all adjustments (including reclassifications and normal recurring adjustments) necessary to present fairly the financial position as of September 30, 2020, and results of operations and cash flows for all periods presented. The interim results presented are not necessarily indicative of results that can be expected for a full year.
Use of estimates and assumptions	(b) Use of estimates and assumptions The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant areas requiring estimates include valuation and recognition of stock-based compensation, leases, amortization and depreciation of property, plant and equipment and intangible assets, and pre-clinical and other accruals. Actual results could differ from those estimates.
Reclassification	(c) Reclassification The Company reclassified prior year amortization of operating lease right-of-use assets, depreciation and amortization, and changes in operating lease liabilities in the condensed consolidated statements of cash flows to conform to current year presentation. This reclassification had no effect on net cash used in operating activities.
Leases	(d) Leases At contract inception, the Company determines if the contract is a lease or contains a lease. Operating leases are recorded as operating lease right-of-use assets, operating lease liabilities and non-current operating lease liabilities. Finance leases are recorded as finance lease right-of-use assets, finance lease liabilities and non-current finance lease liabilities. Right-of-use assets and lease liabilities are recognized on the lease commencement date based on the estimated present value of lease payments over the lease term. To determine the present value of the lease payments, the Company utilizes its estimated incremental borrowing rate based on information available at the lease commencement date as the rate implicit in the lease is not readily determinable. The right-of-use assets are recorded net of any lease incentives received. Variable lease cost primarily includes building operating expenses as charged to the Company by its landlords. For leases of office space with a lease term 12 months or less and which do not include an option to purchase the underlying asset, the Company has elected to recognize the lease payments in the statement of operations on a straight-line basis over the lease term. For leases of office space, the Company has elected to not separate the lease components from the non-lease components.
Fair value of financial instruments	(e) Fair value of financial instruments The carrying amounts of certain of the Company’s financial instruments, including cash and cash equivalents, restricted cash, receivables, accounts payable and other liabilities, approximate their fair values because of their nature and/or short maturities. At September 30, 2020, and December 31, 2019, the Company had $108.3 million and $40.0 million in money market funds, respectively. Money market funds are level one financial instruments as they are valued at fair value, which is the closing price reported by the fund sponsor from an actively traded exchange.
Earnings (loss) per share	(f) Earnings (loss) per share Basic net loss per share is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period, without consideration for common stock equivalents. Common stock equivalents such as outstanding stock options and unvested restricted stock units are included in the calculation of diluted earnings per share only in periods of net income. Such common stock equivalents are excluded in the calculation of diluted net loss per share in periods of net loss as inclusion of such amounts would be anti-dilutive. Outstanding pre-funded warrants of 12,663,010 are considered outstanding as of their issuance date and are included in the basic and diluted net loss per share calculation because they are fully vested and exercisable at any time for a nominal cash consideration.
Asset acquisitions	(g) Asset acquisitions At the time of acquisition, the Company determines if a transaction should be accounted for as a business combination or acquisition of assets. For an acquisition of assets, the cost of acquiring the asset group, including transaction costs, is allocated to the acquired assets and assumed liabilities based on their relative fair values without giving rise to goodwill. Acquired in-process research and development assets are expensed if management determines that the assets do not have an alternative future use. Other long-lived intangible assets are recorded at the acquired cost and amortized using the straight-line method over their estimated useful life. The intangible asset is tested for impairment when events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. The Company recognizes an impairment loss when carrying amount is not recoverable and the estimated fair value of the intangible asset is less than its carrying value.
Recently issued and recently adopted accounting standards	(h) Recently issued and recently adopted accounting standards In December 2019, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2019-12 “Simplifying the Accounting for Income Taxes.” The objective of the standard is to improve areas of GAAP by removing certain exceptions permitted by Accounting Standards Codification (“ASC”) Topic 740 - Income Taxes and clarifying existing guidance to facilitate consistent application. ASU 2019-12 is effective for fiscal years and interim periods beginning after December 15, 2020. The Company has incurred net losses since its inception and maintains a full valuation allowance on the net deferred tax assets. As such, the Company does not expect the adoption of this standard to have a material impact on the financial condition, results of operations and cash flows, or financial statement disclosures. In August 2018, the FASB issued “ASU 2018-15, Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract.” The objective of the standard is to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. We adopted this standard on January 1, 2020 on a prospective basis. The adoption of this ASU did not have a material impact on the Company’s financial condition, results of operations, cash flows, and financial statement disclosures.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2020

(a) Basis of presentation

The accompanying unaudited condensed consolidated financial statements are presented in United States (“U.S.”) dollars and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim financial information. Accordingly, these consolidated financial statements do not include all of the information and footnotes required for complete consolidated financial statements and should be read in conjunction with the audited consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019, filed with the Securities and Exchange Commission on March 12, 2020.

In management’s opinion, the unaudited condensed consolidated financial statements reflect all adjustments (including reclassifications and normal recurring adjustments) necessary to present fairly the financial position as of September 30, 2020, and results of operations and cash flows for all periods presented. The interim results presented are not necessarily indicative of results that can be expected for a full year.

Use of estimates and assumptions

(b) Use of estimates and assumptions

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant areas requiring estimates include valuation and recognition of stock-based compensation, leases, amortization and depreciation of property, plant and equipment and intangible assets, and pre-clinical and other accruals. Actual results could differ from those estimates.

Reclassification

The Company reclassified prior year amortization of operating lease right-of-use assets, depreciation and amortization, and changes in operating lease liabilities in the condensed consolidated statements of cash flows to conform to current year presentation. This reclassification had no effect on net cash used in operating activities.

Leases

(d) Leases

At contract inception, the Company determines if the contract is a lease or contains a lease. Operating leases are recorded as operating lease right-of-use assets, operating lease liabilities and non-current operating lease liabilities. Finance leases are recorded as finance lease right-of-use assets, finance lease liabilities and non-current finance lease liabilities.

Right-of-use assets and lease liabilities are recognized on the lease commencement date based on the estimated present value of lease payments over the lease term. To determine the present value of the lease payments, the Company utilizes its estimated incremental borrowing rate based on information available at the lease commencement date as the rate implicit in the lease is not readily determinable. The right-of-use assets are recorded net of any lease incentives received. Variable lease cost primarily includes building operating expenses as charged to the Company by its landlords.

For leases of office space with a lease term 12 months or less and which do not include an option to purchase the underlying asset, the Company has elected to recognize the lease payments in the statement of operations on a straight-line basis over the lease term.

For leases of office space, the Company has elected to not separate the lease components from the non-lease components.

Fair value of financial instruments

(e) Fair value of financial instruments

The carrying amounts of certain of the Company’s financial instruments, including cash and cash equivalents, restricted cash, receivables, accounts payable and other liabilities, approximate their fair values because of their nature and/or short maturities.

At September 30, 2020, and December 31, 2019, the Company had $108.3 million and $40.0 million in money market funds, respectively. Money market funds are level one financial instruments as they are valued at fair value, which is the closing price reported by the fund sponsor from an actively traded exchange.

Earnings (loss) per share

(f) Earnings (loss) per share

Basic net loss per share is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period, without consideration for common stock equivalents. Common stock equivalents such as outstanding stock options and unvested restricted stock units are included in the calculation of diluted earnings per share only in periods of net income. Such common stock equivalents are excluded in the calculation of diluted net loss per share in periods of net loss as inclusion of such amounts would be anti-dilutive. Outstanding pre-funded warrants of 12,663,010 are considered outstanding as of their issuance date and are included in the basic and diluted net loss per share calculation because they are fully vested and exercisable at any time for a nominal cash consideration.

Asset acquisitions

(g) Asset acquisitions

At the time of acquisition, the Company determines if a transaction should be accounted for as a business combination or acquisition of assets.

For an acquisition of assets, the cost of acquiring the asset group, including transaction costs, is allocated to the acquired assets and assumed liabilities based on their relative fair values without giving rise to goodwill. Acquired in-process research and development assets are expensed if management determines that the assets do not have an alternative future use. Other long-lived intangible assets are recorded at the acquired cost and amortized using the straight-line method over their estimated useful life.

The intangible asset is tested for impairment when events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. The Company recognizes an impairment loss when carrying amount is not recoverable and the estimated fair value of the intangible asset is less than its carrying value.

Recently issued and recently adopted accounting standards

(h) Recently issued and recently adopted accounting standards

In December 2019, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2019-12 “Simplifying the Accounting for Income Taxes.” The objective of the standard is to improve areas of GAAP by removing certain exceptions permitted by Accounting Standards Codification (“ASC”) Topic 740 - Income Taxes and clarifying existing guidance to facilitate consistent application. ASU 2019-12 is effective for fiscal years and interim periods beginning after December 15, 2020. The Company has incurred net losses since its inception and maintains a full valuation allowance on the net deferred tax assets. As such, the Company does not expect the adoption of this standard to have a material impact on the financial condition, results of operations and cash flows, or financial statement disclosures.

In August 2018, the FASB issued “ASU 2018-15, Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract.” The objective of the standard is to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. We adopted this standard on January 1, 2020 on a prospective basis. The adoption of this ASU did not have a material impact on the Company’s financial condition, results of operations, cash flows, and financial statement disclosures.