Significant Accounting Policies	6 Months Ended
Jun. 30, 2021
Significant Accounting Policies
Significant Accounting Policies	Note 2—Significant Accounting Policies Revenue Recognition When we enter into a customer contract, we perform the following five steps: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) we satisfy a performance obligation. We generally record revenue from product sales when the product is delivered to our wholesalers. Product sales are recorded net of wholesaler distribution fees and estimated chargebacks, rebates, returns and purchase-volume discounts. Accruals or allowances are established for these deductions in the same period when revenue is recognized, and actual amounts incurred are offset against the applicable accruals or allowances. We reflect each of these accruals or allowances as either a reduction in the related accounts receivable or as an accrued liability depending on how the amount is expected to be settled. Inventory Inventory is stated at the lower of cost or market determined on a specific identification basis in a manner that approximates the first-in, first-out (“FIFO”) method. Costs include amounts related to third-party manufacturing, transportation and internal labor and overhead. Capitalization of costs as inventory begins when regulatory approval of the product candidate is reasonably assured in the U.S. or the European Union (“EU”). We expense inventory costs related to product candidates as research and development expenses prior to receiving regulatory approval in the respective territory. Inventory is reduced to net realizable value for excess and obsolete inventories based on forecasted demand. Right of Use Assets and Related Lease Liabilities We record operating leases as right-of-use assets and recognize the related lease liabilities equal to the fair value of the lease payments using our incremental borrowing rate when the implicit rate in the lease agreement is not readily available. We recognize variable lease payments when incurred. Costs associated with operating lease assets are recognized on a straight-line basis within operating expenses over the term of the lease. We record finance leases as a component of property and equipment and amortize these assets within operating expenses on a straight-line basis to their residual values over the shorter of the term of the underlying lease or the estimated useful life of the equipment. The interest component of a finance lease is included in interest expense and recognized using the effective interest method over the lease term. We account for leases with initial terms of 12 months or less as operating expenses on a straight-line basis over the lease term. Stock-Based Compensation Stock-based compensation expense is recognized for all share-based payments based on estimated fair values as of the date of grant. The fair value of our stock options is calculated using the Black-Scholes option-pricing model, which requires judgmental assumptions around volatility, forfeiture rates and expected option term. Compensation expense is recognized over the optionees’ requisite service periods, which is generally the vesting period, using the straight-line method. Forfeiture expense is estimated at the time of grant and revised in subsequent periods if actual forfeitures differ from those estimates. Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. We recognize the effect of income tax positions only if those positions are more likely than not of being sustained upon an examination. A valuation allowance is established when it is more likely than not that the deferred tax assets will not be realized. Recently Adopted Pronouncements On January 1, 2021, we adopted Accounting Standard Update (“ASU”) 2020-06, Debt—Debt with Conversion Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40) on a modified retrospective basis. ASU 2020-06 removes the separate liability and equity accounting for our convertible senior notes. Consequently, we now account for our convertible senior notes wholly as debt. (See “Note 3 – Net Loss Per Share” and “Note 7 – Unsecured Convertible Senior Notes” for further information) On January 1, 2021, we adopted ASU 2019-12, Income Taxes (Topic 740), which is intended to simplify various aspects of the income tax accounting guidance, including elimination of the exception to the incremental approach of intra-period tax allocation when there is a loss from continuing operations and income or gain from other items (for example, other comprehensive income). We adopted the standard on a prospective basis and the impact to our consolidated financial statements for the three and six months ended June 30, 2021 was immaterial.

Significant Accounting Policies

6 Months Ended

Jun. 30, 2021

Note 2—Significant Accounting Policies

Revenue Recognition

When we enter into a customer contract, we perform the following five steps: (i) identify the contract with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) we satisfy a performance obligation.

We generally record revenue from product sales when the product is delivered to our wholesalers. Product sales are recorded net of wholesaler distribution fees and estimated chargebacks, rebates, returns and purchase-volume discounts. Accruals or allowances are established for these deductions in the same period when revenue is recognized, and actual amounts incurred are offset against the applicable accruals or allowances. We reflect each of these accruals or allowances as either a reduction in the related accounts receivable or as an accrued liability depending on how the amount is expected to be settled.

Inventory

Inventory is stated at the lower of cost or market determined on a specific identification basis in a manner that approximates the first-in, first-out (“FIFO”) method. Costs include amounts related to third-party manufacturing, transportation and internal labor and overhead. Capitalization of costs as inventory begins when regulatory approval of the product candidate is reasonably assured in the U.S. or the European Union (“EU”). We expense inventory costs related to product candidates as research and development expenses prior to receiving regulatory approval in the respective territory. Inventory is reduced to net realizable value for excess and obsolete inventories based on forecasted demand.

Right of Use Assets and Related Lease Liabilities

We record operating leases as right-of-use assets and recognize the related lease liabilities equal to the fair value of the lease payments using our incremental borrowing rate when the implicit rate in the lease agreement is not readily

available. We recognize variable lease payments when incurred. Costs associated with operating lease assets are recognized on a straight-line basis within operating expenses over the term of the lease. We record finance leases as a component of property and equipment and amortize these assets within operating expenses on a straight-line basis to their residual values over the shorter of the term of the underlying lease or the estimated useful life of the equipment. The interest component of a finance lease is included in interest expense and recognized using the effective interest method over the lease term. We account for leases with initial terms of 12 months or less as operating expenses on a straight-line basis over the lease term.

Stock-Based Compensation

Stock-based compensation expense is recognized for all share-based payments based on estimated fair values as of the date of grant. The fair value of our stock options is calculated using the Black-Scholes option-pricing model, which requires judgmental assumptions around volatility, forfeiture rates and expected option term. Compensation expense is recognized over the optionees’ requisite service periods, which is generally the vesting period, using the straight-line method. Forfeiture expense is estimated at the time of grant and revised in subsequent periods if actual forfeitures differ from those estimates.

Income Taxes

Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applied to taxable income in the years in which those temporary differences are expected to be recovered or settled. We recognize the effect of income tax positions only if those positions are more likely than not of being sustained upon an examination. A valuation allowance is established when it is more likely than not that the deferred tax assets will not be realized.

Recently Adopted Pronouncements

On January 1, 2021, we adopted Accounting Standard Update (“ASU”) 2020-06, Debt—Debt with Conversion Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40) on a modified retrospective basis. ASU 2020-06 removes the separate liability and equity accounting for our convertible senior notes. Consequently, we now account for our convertible senior notes wholly as debt. (See “Note 3 – Net Loss Per Share” and “Note 7 – Unsecured Convertible Senior Notes” for further information)

On January 1, 2021, we adopted ASU 2019-12, Income Taxes (Topic 740), which is intended to simplify various aspects of the income tax accounting guidance, including elimination of the exception to the incremental approach of intra-period tax allocation when there is a loss from continuing operations and income or gain from other items (for example, other comprehensive income). We adopted the standard on a prospective basis and the impact to our consolidated financial statements for the three and six months ended June 30, 2021 was immaterial.