XML 55 R44.htm IDEA: XBRL DOCUMENT
v3.24.3

Subsequent Events (Additional Information) (Details) - USD ($) $ in Millions | Nov. 08, 2024 | Oct. 29, 2024 | Sep. 30, 2025 | Mar. 31, 2025 | Oct. 31, 2024 | Oct. 21, 2024 | Sep. 30, 2024 | Jun. 30, 2024 | Dec. 31, 2023 | Nov. 07, 2022
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Milestone payment |  |  |  |  |  |  | $ 225.0 |  |  |
Workforce reduction, percent |  | 39.00% |  |  |  |  |  |  |  |
GSK License Agreement [Member] | GSK [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Milestone payment |  |  | $ 23.8 | $ 23.8 |  |  |  | $ 23.8 | $ 23.8 | $ 66.0
SPR720 [Member] | Subsequent Event [Member] | Restructuring and Reduction in Workforce [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Workforce reduction, percent |  | 39.00% |  |  |  |  |  |  |  |
Severance Costs |  | $ 1.1 |  |  |  |  |  |  |  |
Retention Award Payable |  | $ 4.4 |  |  |  |  |  |  |  |
Amendment 4 [Member] | GSK License Agreement [Member] | GSK [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Milestone payment |  |  |  |  | $ 0.8 |  |  |  |  |
Amendment 4 [Member] | GSK License Agreement [Member] | GSK [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Milestone payment |  |  |  |  |  | $ 0.8 |  |  |  |
Retention Program [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Salary Plus Target Annual Bonus | 75.00% |  |  |  |  |  |  |  |  |
Total Retention Payments | $ 2.1 |  |  |  |  |  |  |  |  |

X
- Definition Bonus percent + References No definition available. + Details
Name: | spro_BonusPercent
Namespace Prefix: | spro_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Milestone payment upon submission of a new drug application. + References No definition available. + Details
Name: | spro_MilestonePaymentUponSubmissionOfANewDrugApplication
Namespace Prefix: | spro_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Retention Award Payable + References No definition available. + Details
Name: | spro_RetentionAwardPayable
Namespace Prefix: | spro_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Retention Program Payable Amount + References No definition available. + Details
Name: | spro_RetentionProgramPayableAmount
Namespace Prefix: | spro_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Workforce Reduction, Percent + References No definition available. + Details
Name: | spro_WorkforceReductionPercent
Namespace Prefix: | spro_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation. + 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_SeveranceCosts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481674/830-30-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 855 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483399/855-10-50-2 + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=spro_GskLicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=spro_GlaxoSmithKlineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=spro_RestructuringAndReductionInWorkforceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=spro_AmendmentFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=spro_RetentionProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |