3.26.1 html 124 240 1 false 41 0 false 5 false false R1.htm 75000 - Document - Document and Entity Information Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 75010 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetsUnaudited CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) Statements 2 false false R3.htm 75020 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/StatementCondensedConsolidatedBalanceSheetsUnauditedParenthetical CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) Statements 3 false false R4.htm 75030 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLossUnaudited CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) Statements 4 false false R5.htm 75040 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/StatementCondensedConsolidatedStatementsOfCashFlowsUnaudited CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) Statements 5 false false R6.htm 75050 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/StatementCondensedConsolidatedStatementsOfChangesInEquityUnaudited CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) Statements 6 false false R7.htm 995410 - Disclosure - Pay vs Performance Disclosure Sheet http://xbrl.sec.gov/ecd/role/PvpDisclosure Pay vs Performance Disclosure Notes 7 false false R8.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 8 false false R9.htm 995455 - Disclosure - Nature of Business Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureNatureOfBusiness Nature of Business Notes 9 false false R10.htm 995465 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPolicies1 Basis of Presentation and Summary of Significant Accounting Policies Notes 10 false false R11.htm 995475 - Disclosure - Recent Accounting Pronouncements Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureRecentAccountingPronouncements Recent Accounting Pronouncements Notes 11 false false R12.htm 995485 - Disclosure - Fair Value Measurement Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureFairValueMeasurement1 Fair Value Measurement Notes 12 false false R13.htm 995495 - Disclosure - Prepaid Expenses and Other Current Assets Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePrepaidExpensesAndOtherCurrentAssets1 Prepaid Expenses and Other Current Assets Notes 13 false false R14.htm 995505 - Disclosure - Property and Equipment , net Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePropertyAndEquipmentNet1 Property and Equipment , net Notes 14 false false R15.htm 995525 - Disclosure - Leases Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLeases Leases Notes 15 false false R16.htm 995535 - Disclosure - Other Current Liabilities Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureOtherCurrentLiabilities1 Other Current Liabilities Notes 16 false false R17.htm 995545 - Disclosure - Accrued Expenses Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureAccruedExpenses1 Accrued Expenses Notes 17 false false R18.htm 995565 - Disclosure - Warrant Liability Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureWarrantLiability1 Warrant Liability Notes 18 false false R19.htm 995575 - Disclosure - Shareholders' Equity Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareholdersEquity1 Shareholders' Equity Notes 19 false false R20.htm 995615 - Disclosure - Share Based Compensation Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensation1 Share Based Compensation Notes 20 false false R21.htm 995625 - Disclosure - Loss Per Share Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLossPerShare1 Loss Per Share Notes 21 false false R22.htm 995635 - Disclosure - Commitments and Contingencies Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureCommitmentsAndContingencies1 Commitments and Contingencies Notes 22 false false R23.htm 995645 - Disclosure - Related Party Disclosures Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureRelatedPartyDisclosures1 Related Party Disclosures Notes 23 false false R24.htm 995665 - Disclosure - Segment information Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureSegmentInformation Segment information Notes 24 false false R25.htm 995675 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies (Policies) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies Basis of Presentation and Summary of Significant Accounting Policies (Policies) Policies http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPolicies1 25 false false R26.htm 995695 - Disclosure - Fair Value Measurement (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureFairValueMeasurementTables Fair Value Measurement (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureFairValueMeasurement1 26 false false R27.htm 995705 - Disclosure - Prepaid Expenses and Other Current Assets (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePrepaidExpensesAndOtherCurrentAssetsTables Prepaid Expenses and Other Current Assets (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePrepaidExpensesAndOtherCurrentAssets1 27 false false R28.htm 995715 - Disclosure - Property and Equipment , net (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePropertyAndEquipmentNetTables Property and Equipment , net (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePropertyAndEquipmentNet1 28 false false R29.htm 995735 - Disclosure - Leases (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLeasesTables Leases (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLeases 29 false false R30.htm 995745 - Disclosure - Other Current Liabilities (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureOtherCurrentLiabilitiesTables Other Current Liabilities (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureOtherCurrentLiabilities1 30 false false R31.htm 995755 - Disclosure - Accrued Expenses (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureAccruedExpensesTables Accrued Expenses (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureAccruedExpenses1 31 false false R32.htm 995775 - Disclosure - Warrant Liability (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureWarrantLiabilityTables Warrant Liability (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureWarrantLiability1 32 false false R33.htm 995785 - Disclosure - Shareholders' Equity (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareholdersEquityTables Shareholders' Equity (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareholdersEquity1 33 false false R34.htm 995795 - Disclosure - Share Based Compensation (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensationTables Share Based Compensation (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensation1 34 false false R35.htm 995805 - Disclosure - Loss Per Share (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLossPerShareTables Loss Per Share (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLossPerShare1 35 false false R36.htm 995815 - Disclosure - Segment information (Tables) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureSegmentInformationTables Segment information (Tables) Tables http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureSegmentInformation 36 false false R37.htm 995825 - Disclosure - Basis of Presentation and Summary of Significant Accounting Policies (Additional Information) (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails Basis of Presentation and Summary of Significant Accounting Policies (Additional Information) (Details) Details http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies 37 false false R38.htm 995835 - Disclosure - Fair Value Measurement (Additional Information) (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureFairValueMeasurementAdditionalInformationDetails Fair Value Measurement (Additional Information) (Details) Details http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureFairValueMeasurementTables 38 false false R39.htm 995845 - Disclosure - Fair Value Measurement - Schedule of financial assets and liabilities measured at fair value on a recurring basis (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureFairValueMeasurementScheduleOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueOnARecurringBasisDetails Fair Value Measurement - Schedule of financial assets and liabilities measured at fair value on a recurring basis (Details) Details 39 false false R40.htm 995855 - Disclosure - Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses And Other Current Assets (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePrepaidExpensesAndOtherCurrentAssetsScheduleOfPrepaidExpensesAndOtherCurrentAssetsDetails Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses And Other Current Assets (Details) Details 40 false false R41.htm 995875 - Disclosure - Property and Equipment , net - Summary of Property and Equipment, Net (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePropertyAndEquipmentNetSummaryOfPropertyAndEquipmentNetDetails Property and Equipment , net - Summary of Property and Equipment, Net (Details) Details 41 false false R42.htm 995885 - Disclosure - Property and Equipment , net - Additional Information (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosurePropertyAndEquipmentNetAdditionalInformationDetails Property and Equipment , net - Additional Information (Details) Details 42 false false R43.htm 995905 - Disclosure - Leases (Additional Information) (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLeasesAdditionalInformationDetails Leases (Additional Information) (Details) Details http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLeasesTables 43 false false R44.htm 995915 - Disclosure - Leases - Weighted Average Remaining Lease Term and Discount Rate (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLeasesWeightedAverageRemainingLeaseTermAndDiscountRateDetails Leases - Weighted Average Remaining Lease Term and Discount Rate (Details) Details 44 false false R45.htm 995925 - Disclosure - Leases - Cash Paid for Lease Liabilities (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLeasesCashPaidForLeaseLiabilitiesDetails Leases - Cash Paid for Lease Liabilities (Details) Details 45 false false R46.htm 995935 - Disclosure - Leases - Schedule of Maturities of Operating lease liabilities (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLeasesScheduleOfMaturitiesOfOperatingLeaseLiabilitiesDetails Leases - Schedule of Maturities of Operating lease liabilities (Details) Details 46 false false R47.htm 995955 - Disclosure - Other current liabilities - Schedule of Other current liabilities (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureOtherCurrentLiabilitiesScheduleOfOtherCurrentLiabilitiesDetails Other current liabilities - Schedule of Other current liabilities (Details) Details 47 false false R48.htm 995975 - Disclosure - Accrued Expenses - Schedule of Accrued Expenses (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureAccruedExpensesScheduleOfAccruedExpensesDetails Accrued Expenses - Schedule of Accrued Expenses (Details) Details 48 false false R49.htm 995985 - Disclosure - Convertible loan notes and equity classified warrants (Additional Information) (Details) Notes http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureConvertibleLoanNotesAndEquityClassifiedWarrantsAdditionalInformationDetails Convertible loan notes and equity classified warrants (Additional Information) (Details) Details 49 false false R50.htm 995995 - Disclosure - Warrant Liability - Summary of change in fair value of the warrant liability (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureWarrantLiabilitySummaryOfChangeInFairValueOfTheWarrantLiabilityDetails Warrant Liability - Summary of change in fair value of the warrant liability (Details) Details 50 false false R51.htm 996005 - Disclosure - Warrant Liability - Summary of weighted average inputs to the models used for the fair value of warrants (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureWarrantLiabilitySummaryOfWeightedAverageInputsToTheModelsUsedForTheFairValueOfWarrantsDetails Warrant Liability - Summary of weighted average inputs to the models used for the fair value of warrants (Details) Details 51 false false R52.htm 996015 - Disclosure - Warrant Liability (Additional Information) (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureWarrantLiabilityAdditionalInformationDetails Warrant Liability (Additional Information) (Details) Details http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureWarrantLiabilityTables 52 false false R53.htm 996025 - Disclosure - Shareholders' Equity - Summary of Common Shares (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareholdersEquitySummaryOfCommonSharesDetails Shareholders' Equity - Summary of Common Shares (Details) Details 53 false false R54.htm 996035 - Disclosure - Shareholders' Equity - Additional Information (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareholdersEquityAdditionalInformationDetails Shareholders' Equity - Additional Information (Details) Details 54 false false R55.htm 996125 - Disclosure - Share Based Compensation (Additional Information) (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensationAdditionalInformationDetails Share Based Compensation (Additional Information) (Details) Details http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensationTables 55 false false R56.htm 996135 - Disclosure - Share Based Compensation - Summary of Share Based Compensation (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensationSummaryOfShareBasedCompensationDetails Share Based Compensation - Summary of Share Based Compensation (Details) Details 56 false false R57.htm 996145 - Disclosure - Share Based Compensation - Summary of Option Activity and Related Information (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensationSummaryOfOptionActivityAndRelatedInformationDetails Share Based Compensation - Summary of Option Activity and Related Information (Details) Details 57 false false R58.htm 996155 - Disclosure - Share Based Compensation - Summary of Assumptions used in Black-Scholes Option Pricing Model (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensationSummaryOfAssumptionsUsedInBlackscholesOptionPricingModelDetails Share Based Compensation - Summary of Assumptions used in Black-Scholes Option Pricing Model (Details) Details 58 false false R59.htm 996165 - Disclosure - Share Based Compensation - Summary of Restricted Stock Unit Activity and Related Information (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureShareBasedCompensationSummaryOfRestrictedStockUnitActivityAndRelatedInformationDetails Share Based Compensation - Summary of Restricted Stock Unit Activity and Related Information (Details) Details 59 false false R60.htm 996185 - Disclosure - Loss per Share - Schedule of Weighted Average Number of Ordinary Shares Outstanding and The Effect of Dilutive Ordinary Share (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLossPerShareScheduleOfWeightedAverageNumberOfOrdinarySharesOutstandingAndTheEffectOfDilutiveOrdinaryShareDetails Loss per Share - Schedule of Weighted Average Number of Ordinary Shares Outstanding and The Effect of Dilutive Ordinary Share (Details) Details 60 false false R61.htm 996195 - Disclosure - Loss per Share - Schedule of Potentially Dilutive Shares Were Not Included In The Calculation of Diluted Shares Outstanding (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureLossPerShareScheduleOfPotentiallyDilutiveSharesWereNotIncludedInTheCalculationOfDilutedSharesOutstandingDetails Loss per Share - Schedule of Potentially Dilutive Shares Were Not Included In The Calculation of Diluted Shares Outstanding (Details) Details 61 false false R62.htm 996205 - Disclosure - Commitments and Contingencies (Additional Information) (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails Commitments and Contingencies (Additional Information) (Details) Details http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureCommitmentsAndContingencies1 62 false false R63.htm 996215 - Disclosure - Related Party Disclosures (Additional Information) (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureRelatedPartyDisclosuresAdditionalInformationDetails Related Party Disclosures (Additional Information) (Details) Details http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureRelatedPartyDisclosures1 63 false false R64.htm 996235 - Disclosure - Segment information - Schedule of Financial Data for the Company's Reportable Segment (Details) Sheet http://www.mereobiopharma.com/20260331/taxonomy/role/DisclosureSegmentInformationScheduleOfFinancialDataForTheCompanysReportableSegmentDetails Segment information - Schedule of Financial Data for the Company's Reportable Segment (Details) Details 64 false false All Reports Book All Reports mreo-20260331.htm mreo-20260331.xsd http://fasb.org/us-gaap/2025 http://xbrl.sec.gov/dei/2025 http://xbrl.sec.gov/ecd/2025 false false