XML 103 R72.htm IDEA: XBRL DOCUMENT
v3.25.4

REVENUE FROM CONTRACTS WITH CUSTOMERS - Narrative (Details) $ in Thousands |  |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Dec. 03, 2024 USD ($) performanceObligation | Dec. 12, 2021 USD ($) | Jul. 31, 2025 USD ($) | Feb. 28, 2025 USD ($) | Dec. 31, 2025 USD ($) | Dec. 31, 2024 USD ($) | Dec. 31, 2021 USD ($)
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Total revenue |  |  |  |  | $ 244,061 | $ 3,550 |
Accounts receivable |  |  |  |  | 3,567 | 2,742 |
License revenue |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Total revenue |  |  |  |  | 205,355 | 3,000 |
Service revenue |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Total revenue |  |  |  |  | 38,500 |  |
Takeda Pharmaceuticals U.S.A., Inc. | License revenue |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Upfront license fee | $ 200,000 |  |  |  |  |  |
Reimbursement from limited partnership investment | 51,400 |  |  |  |  |  |
Takeda Pharmaceuticals U.S.A., Inc. | License and Know-How |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Upfront license fee | 195,400 |  |  |  |  |  |
Takeda Pharmaceuticals U.S.A., Inc. | Transition Services |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Upfront license fee | $ 56,100 |  |  |  |  |  |
Hansoh Agreement | Hansoh Shanghai Healthtech Co Ltd |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Total revenue |  | $ 18,000 |  |  |  |  |
Revenue, remaining performance obligation, development milestones, variable consideration |  |  |  |  | 23,500 |  |
Revenue, remaining performance obligation, sales milestones, variable consideration amount |  |  |  |  | $ 144,000 |  |
Upfront license fee |  |  |  |  |  | 3,000 | $ 20,000
Withholding taxes from upfront fee |  |  |  |  |  | 300 | $ 2,000
License Agreement | Maximum |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Term of the TSA | fifteen |  |  |  |  |  |
License Agreement | Minimum |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Term of the TSA | six |  |  |  |  |  |
License Agreement | Hansoh Shanghai Healthtech Co Ltd |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Expiration period |  |  |  |  | 10 years |  |
License Agreement | Takeda Pharmaceuticals U.S.A., Inc. |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Total revenue |  |  | $ 10,000 |  | $ 10,000 |  |
Expiration period |  |  |  |  | 10 years |  |
License agreement upfront fee |  |  |  | $ 200,000 |  |  |
Potential milestone, development based milestones |  |  |  |  | $ 80,000 |  |
Potential milestone payments, commercial-based milestones |  |  |  |  | 280,000 |  |
Potential milestone payments, sales-based milestones | $ 740,000 |  |  |  |  |  |
Number of performance obligations | performanceObligation | 2 |  |  |  |  |  |
Accounts receivable |  |  |  |  | 3,600 | 0 |
Tech Transfer Agreement | Manufacturing Technology Transfer Agreement |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Service revenue |  |  |  |  | 100 | 100 |
Supply Agreement | Clinical Product Supply Agreement |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |
Upfront license fee |  |  |  |  | $ 100 | $ 400 |

X
- Definition License Agreement Upfront Fee + References No definition available. + Details
Name: | kros_LicenseAgreementUpfrontFee
Namespace Prefix: | kros_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number Of Performance Obligations + References No definition available. + Details
Name: | kros_NumberOfPerformanceObligations
Namespace Prefix: | kros_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Potential Milestone Payments, Commercial-based Milestones + References No definition available. + Details
Name: | kros_PotentialMilestonePaymentsCommercialBasedMilestones
Namespace Prefix: | kros_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Potential Milestone Payments, Development Based Milestones + References No definition available. + Details
Name: | kros_PotentialMilestonePaymentsDevelopmentBasedMilestones
Namespace Prefix: | kros_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Potential Milestone Payments, Sales-based Milestones + References No definition available. + Details
Name: | kros_PotentialMilestonePaymentsSalesBasedMilestones
Namespace Prefix: | kros_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Research and Development Arrangement, Contract to Perform for Others, Expiration Period + References No definition available. + Details
Name: | kros_ResearchAndDevelopmentArrangementContractToPerformForOthersExpirationPeriod
Namespace Prefix: | kros_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Revenue From Contract With Customer, Withholding Taxes + References No definition available. + Details
Name: | kros_RevenueFromContractWithCustomerWithholdingTaxes
Namespace Prefix: | kros_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Revenue, Remaining Performance Obligation, Development Milestones, Variable Consideration + References No definition available. + Details
Name: | kros_RevenueRemainingPerformanceObligationDevelopmentMilestonesVariableConsideration
Namespace Prefix: | kros_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Revenue, Remaining Performance Obligation, Sales Milestones, Variable Consideration + References No definition available. + Details
Name: | kros_RevenueRemainingPerformanceObligationSalesMilestonesVariableConsideration
Namespace Prefix: | kros_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Service And Other Revenue + References No definition available. + Details
Name: | kros_ServiceAndOtherRevenue
Namespace Prefix: | kros_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481990/310-10-45-2 + Details
Name: | us-gaap_AccountsReceivableNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-5 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 Reference 9: http://www.xbrl.org/2003/role/exampleRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 91 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479777/606-10-55-91 + Details
Name: | us-gaap_DisaggregationOfRevenueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of term of contractual and voluntary fee waiver agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480990/946-20-50-7 + Details
Name: | us-gaap_InvestmentCompanyFeeWaiverTerms
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition A payment from an investee, in which the investment basis has previously been reduced to zero. This amount reduces net cash used in operating activities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 + Details
Name: | us-gaap_ReimbursementFromLimitedPartnershipInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147476153/220-40-55-4 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147476153/220-40-55-14 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 41 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-41 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-42 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-7 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 270 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482964/270-10-50-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (ee) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-32 Reference 8: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-32 Reference 9: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-32 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 924 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 11.L) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479941/924-10-S99-1 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-5 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-30 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-22 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 40 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-40 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-22 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-4 + Details
Name: | us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 41 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-41 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-42 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-7 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 270 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482964/270-10-50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (ee) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-32 Reference 6: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-32 Reference 7: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-32 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 924 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 11.L) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479941/924-10-S99-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-5 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-30 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-22 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 40 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-40 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-22 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 606 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-4 + Details
Name: | us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_LicenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_ServiceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=kros_TakedaPharmaceuticalsU.S.A.Inc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=kros_LicenseAndKnowHowMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=kros_TransitionServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=kros_HansohAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=kros_HansohShanghaiHealthtechCoLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=us-gaap_LicenseAgreementTermsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=kros_TechTransferAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=kros_ManufacturingTechnologyTransferAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=kros_SupplyAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=kros_ClinicalProductSupplyAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |