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  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndDeferredInPeriodWeightedAverageGrantDateFairValue" id="bcyc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAndDeferredInPeriodWeightedAverageGrantDateFairValue" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodSubjectToDeferredSettlementWeightedAverageGrantDateFairValue" id="bcyc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodSubjectToDeferredSettlementWeightedAverageGrantDateFairValue" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="ResearchAndDevelopmentPercentageOfTaxCreditOnTotalExpenditure" id="bcyc_ResearchAndDevelopmentPercentageOfTaxCreditOnTotalExpenditure" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ShareBasedCompensationArrangementsByShareBasedPaymentAwardVestingNumberOfEqualAnnualInstallments" id="bcyc_ShareBasedCompensationArrangementsByShareBasedPaymentAwardVestingNumberOfEqualAnnualInstallments" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ShareBasedPaymentArrangementThreeYearVestMember" id="bcyc_ShareBasedPaymentArrangementThreeYearVestMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="NumberOfVotePerShare" id="bcyc_NumberOfVotePerShare" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="InducementPlan2024Member" id="bcyc_InducementPlan2024Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="NumberOfGeographicRegionsInWhichOperating" id="bcyc_NumberOfGeographicRegionsInWhichOperating" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="FinanceLeaseCost" id="bcyc_FinanceLeaseCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="SingleReportableSegmentMember" id="bcyc_SingleReportableSegmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InternalProgramProductCandidateBicycleToxinConjugateMoleculeBT8009Member" id="bcyc_InternalProgramProductCandidateBicycleToxinConjugateMoleculeBT8009Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InternalProgramProductCandidateBicycleToxinConjugateMoleculeBT5528Member" id="bcyc_InternalProgramProductCandidateBicycleToxinConjugateMoleculeBT5528Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InternalProgramBicycleTumorTargetedImmuneCellAgonistsBT7480Member" id="bcyc_InternalProgramBicycleTumorTargetedImmuneCellAgonistsBT7480Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ProjectSpecificCosts" id="bcyc_ProjectSpecificCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ResearchAndDevelopmentDiscoveryPlatformAndOtherExpenses" id="bcyc_ResearchAndDevelopmentDiscoveryPlatformAndOtherExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ResearchAndDevelopmentEmployeeAndContractorRelatedExpenses" id="bcyc_ResearchAndDevelopmentEmployeeAndContractorRelatedExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ResearchAndDevelopmentShareBasedPaymentArrangementExpense" id="bcyc_ResearchAndDevelopmentShareBasedPaymentArrangementExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="FacilityExpenses" id="bcyc_FacilityExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ResearchAndDevelopmentTaxCreditsIncentivesAndGovernmentGrants" id="bcyc_ResearchAndDevelopmentTaxCreditsIncentivesAndGovernmentGrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="GeneralAndAdministrativeShareBasedPaymentArrangementExpense" id="bcyc_GeneralAndAdministrativeShareBasedPaymentArrangementExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingNumber" id="bcyc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingNumber" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue" id="bcyc_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="ResearchAndDevelopmentPercentageOfTaxCreditOnTotalExpenditureForNonResearchAndDevelopmentIntensiveEntity" id="bcyc_ResearchAndDevelopmentPercentageOfTaxCreditOnTotalExpenditureForNonResearchAndDevelopmentIntensiveEntity" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="AlethiaYoungMember" id="bcyc_AlethiaYoungMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CostReductionInitiativesMember" id="bcyc_CostReductionInitiativesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CharlesSwantonMember" id="bcyc_CharlesSwantonMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LeaseRentFreePeriod" id="bcyc_LeaseRentFreePeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ContractWithCustomerLiabilityRevenueRecognizedContractModificationsAndExpirationOfMaterialRights" id="bcyc_ContractWithCustomerLiabilityRevenueRecognizedContractModificationsAndExpirationOfMaterialRights" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ExpenditureQualifiedAsResearchAndDevelopmentIntensiveMember" id="bcyc_ExpenditureQualifiedAsResearchAndDevelopmentIntensiveMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ExpenditureNotQualifiedAsResearchAndDevelopmentIntensiveMember" id="bcyc_ExpenditureNotQualifiedAsResearchAndDevelopmentIntensiveMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InternalProgramProductCandidateBicycleRadioconjugateBT1702Member" id="bcyc_InternalProgramProductCandidateBicycleRadioconjugateBT1702Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="StrategicReprioritizationOfClinicalPortfolioMember" id="bcyc_StrategicReprioritizationOfClinicalPortfolioMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ContractTerminationCosts" id="bcyc_ContractTerminationCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
</xsd:schema>
