Summary of Significant Accounting Policies (Polices)	6 Months Ended
Jun. 30, 2020
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The accompanying unaudited interim financial statements for Xencor, Inc. (the Company, Xencor, we or us) have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information. The financial statements include all adjustments (consisting only of normal recurring adjustments) that the management of the Company believes are necessary for a fair presentation of the periods presented. The preparation of interim financial statements requires the use of management’s estimates and assumptions that affect reported amounts of assets and liabilities at the date of the interim financial statements and the reported revenues and expenditures during the reported periods. These interim financial results are not necessarily indicative of the results expected for the full fiscal year or for any subsequent interim period. The accompanying unaudited interim financial statements and related notes should be read in conjunction with the audited financial statements and notes thereto included in the Company’s 2019 Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on February 25, 2020.
Use of Estimates	Use of Estimates The preparation of interim financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, other comprehensive gain (loss) and the related disclosures. On an ongoing basis, management evaluates its estimates, including estimates related to its accrued clinical trial and manufacturing development expenses, stock-based compensation expense, intangible assets and related amortization. Significant estimates in these interim financial statements include estimates made for royalties and accrued research and development expenses, stock-based compensation expenses, intangible assets and related amortization, estimated standalone selling price of performance obligations, the likelihood of recognizing variable consideration, and recoverability of deferred tax assets.
Intangible Assets	Intangible Assets The Company maintains definite-lived intangible assets related to certain capitalized costs of acquired licenses and third-party costs incurred in establishing and maintaining its intellectual property rights to its platform technologies and development candidates. These assets are amortized over their useful lives, which are estimated to be the remaining patent life or the contractual term of the license. The straight-line method is used to record amortization expense. The Company assesses its intangible assets for impairment if indicators are present or changes in circumstances suggest that impairment may exist. There were no impairment charges recorded for the three and six months ended June 30, 2020 and 2019. The Company capitalizes certain in-process intangible assets that are then abandoned when they are no longer pursued or used in current research activities. There was no material abandonment of in-process intangible assets during the three and six months ended June 30, 2020 and 2019.
Marketable and Equity Securities	Marketable and Equity Securities The Company has an investment policy that includes guidelines on acceptable investment securities, minimum credit quality, maturity parameters, and concentration and diversification. The Company invests its excess cash primarily in marketable debt securities issued by investment grade institutions. The Company considers its marketable debt securities to be available-for-sale and does not intend to sell these securities, and it is not more likely than not that the Company will be required to sell the securities before recovery of the amortized cost basis. These assets are carried at fair value and any impairment losses and recoveries related to the underlying issuer’s credit standing are recognized within other income (expense), while non-credit related impairment losses and recoveries are recognized within accumulated other comprehensive income (loss). There were no impairment losses or recoveries recorded for the three and six months ended June 30, 2020 and 2019. Accrued interest on marketable debt securities is included in marketable securities’ carrying value. Each reporting period, the Company reviews its portfolio of marketable debt securities, using both quantitative and qualitative factors, to determine if each security’s fair value has declined below its amortized cost basis. The Company also has an investment in an equity security that is carried at fair value with changes in fair value recognized within other income (expense). For equity securities with a readily determinable fair value, the Company remeasures these equity investments at each reporting period until such time that the investment is sold or disposed. If the Company sells an investment, any realized gains and losses on the sale of the securities will be recognized within other income (expense) in the Statement of Comprehensive Income (Loss) in the period of sale.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Pronouncements Adopted in 2020 Effective January 1, 2020, the Company adopted ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as well as ASU No, 2018-19, Codification Improvements to Topic 326, Financial Instruments – Credit Losses. The standard amends guidance on reporting credit losses for assets held at amortized cost basis and also provides an available-for-sale (AFS) debt security impairment model that is a modified version of the other-than-temporary-impairment (OTTI) model. The AFS debt security impairment model no longer allows consideration of the length of time during which the fair value has been less than its amortized cost when determining whether a credit loss exists. The adoption of this standard did not have any impact on the Company’s financial statements. Effective January 1, 2020, the Company adopted ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which modifies the disclosures for transfers between Level 1 and Level 2 of the fair value hierarchy, modifies the Level 3 disclosure requirements for non-public entities and requires additional disclosure for Level 3 fair value hierarchy. The adoption of this standard did not have any impact on the Company’s financial statements. Effective January 1, 2020, the Company adopted ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606, which provides guidance on how to assess whether certain transactions between collaborative arrangement participants should be accounted for within the revenue recognition standard. The adoption of this standard did not have any impact on the Company’s financial statements. Pronouncements Not Yet Effective In December 2019, the Financial Accounting Standards Board (FASB) issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which is effective for fiscal years beginning on and after December 15, 2020, and interim periods within those fiscal years. The standard removes specific exceptions to the general principles in Topic 740 and simplifies the accounting for income taxes. The Company does not anticipate that the standard will have a significant impact on its financial statements. In January 2020, the FASB issued ASU No. 2020-01, which clarifies that a company should consider observable transactions that require a company to either apply or discontinue the equity method of accounting under Topic 323, Investment – Equity Method and Joint Ventures, for the purposes of applying the measurement alternative in accordance with Topic 321 immediately before applying or upon discontinuing the equity method. The amendment is effective for fiscal years beginning after December 15, 2020. The Company does not anticipate that the standard will have a significant impact on its financial statements. There have been no other material changes to the significant accounting policies previously disclosed in the Company’s 2019 Annual Report on Form 10-K.

Summary of Significant Accounting Policies (Polices)

6 Months Ended

Jun. 30, 2020

Summary of Significant Accounting Policies

The accompanying unaudited interim financial statements for Xencor, Inc. (the Company, Xencor, we or us) have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information. The financial statements include all adjustments (consisting only of normal recurring adjustments) that the management of the Company believes are necessary for a fair presentation of the periods presented. The preparation of interim financial statements requires the use of management’s estimates and assumptions that affect reported amounts of assets and liabilities at the date of the interim financial statements and the reported revenues and expenditures during the reported periods. These interim financial results are not necessarily indicative of the results expected for the full fiscal year or for any subsequent interim period.

The accompanying unaudited interim financial statements and related notes should be read in conjunction with the audited financial statements and notes thereto included in the Company’s 2019 Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on February 25, 2020.

Use of Estimates

The preparation of interim financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, other comprehensive gain (loss) and the related disclosures. On an ongoing basis, management evaluates its estimates, including estimates related to its accrued clinical trial and manufacturing development expenses, stock-based compensation expense, intangible assets and related amortization. Significant estimates in these interim financial statements include estimates made for royalties and accrued research and development expenses, stock-based compensation expenses, intangible assets and related amortization, estimated standalone selling price of performance obligations, the likelihood of recognizing variable consideration, and recoverability of deferred tax assets.

Intangible Assets

The Company maintains definite-lived intangible assets related to certain capitalized costs of acquired licenses and third-party costs incurred in establishing and maintaining its intellectual property rights to its platform technologies and development candidates. These assets are amortized over their useful lives, which are estimated to be the remaining patent life or the contractual term of the license. The straight-line method is used to record amortization expense. The Company assesses its intangible assets for impairment if indicators are present or changes in circumstances suggest that impairment may exist. There were no impairment charges recorded for the three and six months ended June 30, 2020 and 2019.

The Company capitalizes certain in-process intangible assets that are then abandoned when they are no longer pursued or used in current research activities. There was no material abandonment of in-process intangible assets during the three and six months ended June 30, 2020 and 2019.

Marketable and Equity Securities

The Company has an investment policy that includes guidelines on acceptable investment securities, minimum credit quality, maturity parameters, and concentration and diversification. The Company invests its excess cash primarily in marketable debt securities issued by investment grade institutions.

The Company considers its marketable debt securities to be available-for-sale and does not intend to sell these securities, and it is not more likely than not that the Company will be required to sell the securities before recovery of the amortized cost basis. These assets are carried at fair value and any impairment losses and recoveries related to the underlying issuer’s credit standing are recognized within other income (expense), while non-credit related impairment losses and recoveries are recognized within accumulated other comprehensive income (loss). There were no impairment losses or recoveries recorded for the three and six months ended June 30, 2020 and 2019. Accrued interest on marketable debt securities is included in marketable securities’ carrying value. Each reporting period, the Company reviews its portfolio of marketable debt securities, using both quantitative and qualitative factors, to determine if each security’s fair value has declined below its amortized cost basis.

The Company also has an investment in an equity security that is carried at fair value with changes in fair value recognized within other income (expense). For equity securities with a readily determinable fair value, the Company remeasures these equity investments at each reporting period until such time that the investment is sold or disposed. If the Company sells an investment, any realized gains and losses on the sale of the securities will be recognized within other income (expense) in the Statement of Comprehensive Income (Loss) in the period of sale.

Recent Accounting Pronouncements

Pronouncements Adopted in 2020

Effective January 1, 2020, the Company adopted ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as well as ASU No, 2018-19, Codification Improvements to Topic 326, Financial Instruments – Credit Losses. The standard amends guidance on reporting credit losses for assets held at amortized cost basis and also provides an available-for-sale (AFS) debt security impairment model that is a modified version of the other-than-temporary-impairment (OTTI) model. The AFS debt security impairment model no longer allows consideration of the length of time during which the fair value has been less than its amortized cost when determining whether a credit loss exists. The adoption of this standard did not have any impact on the Company’s financial statements.

Effective January 1, 2020, the Company adopted ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which modifies the disclosures for transfers between Level 1 and Level 2 of the fair value hierarchy, modifies the Level 3 disclosure requirements for non-public entities and requires additional disclosure for Level 3 fair value hierarchy. The adoption of this standard did not have any impact on the Company’s financial statements.

Effective January 1, 2020, the Company adopted ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606, which provides guidance on how to assess whether certain transactions between collaborative arrangement participants should be accounted for within the revenue recognition standard. The adoption of this standard did not have any impact on the Company’s financial statements.

Pronouncements Not Yet Effective

In December 2019, the Financial Accounting Standards Board (FASB) issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which is effective for fiscal years beginning on and after December 15, 2020, and interim periods within those fiscal years. The standard removes specific exceptions to the general principles in Topic 740 and simplifies the accounting for income taxes. The Company does not anticipate that the standard will have a significant impact on its financial statements.

In January 2020, the FASB issued ASU No. 2020-01, which clarifies that a company should consider observable transactions that require a company to either apply or discontinue the equity method of accounting under Topic 323, Investment – Equity Method and Joint Ventures, for the purposes of applying the measurement alternative in accordance with Topic 321 immediately before applying or upon discontinuing the equity method. The amendment is effective for fiscal years beginning after December 15, 2020. The Company does not anticipate that the standard will have a significant impact on its financial statements.

There have been no other material changes to the significant accounting policies previously disclosed in the Company’s 2019 Annual Report on Form 10-K.