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  <element name="MilestonePaymentPayableUponAchievementOfProductSales" id="mirm_MilestonePaymentPayableUponAchievementOfProductSales" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NonOperatingInterestIncomeExpense" id="mirm_NonOperatingInterestIncomeExpense" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfAdditionalSharesIssued" id="mirm_NumberOfAdditionalSharesIssued" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfProductCandidates" id="mirm_NumberOfProductCandidates" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfVoteEntitledForEachCommonStockholder" id="mirm_NumberOfVoteEntitledForEachCommonStockholder" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OperatingLeaseRightOfUseAssetAmortization" id="mirm_OperatingLeaseRightOfUseAssetAmortization" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OrganizationAndBasisOfPresentationLineItems" id="mirm_OrganizationAndBasisOfPresentationLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OrganizationAndBasisOfPresentationTable" id="mirm_OrganizationAndBasisOfPresentationTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="OwnershipInterestDescription" id="mirm_OwnershipInterestDescription" type="xbrli:stringItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PassThroughCostMember" id="mirm_PassThroughCostMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PromissoryNotesIssuedPrincipalAmount" id="mirm_PromissoryNotesIssuedPrincipalAmount" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="QualifiedEquityFinancingAmount" id="mirm_QualifiedEquityFinancingAmount" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RecentAccountingPronouncementsNotYetAdoptedPolicyTextBlock" id="mirm_RecentAccountingPronouncementsNotYetAdoptedPolicyTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ReclassificationOfRedeemableCommonStockIntoCommonStock" id="mirm_ReclassificationOfRedeemableCommonStockIntoCommonStock" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ReclassificationOfRedeemableCommonStockIntoCommonStockOnInitialPublicOfferingShares" id="mirm_ReclassificationOfRedeemableCommonStockIntoCommonStockOnInitialPublicOfferingShares" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ReclassificationsOfTemporaryToPermanentEquityShares" id="mirm_ReclassificationsOfTemporaryToPermanentEquityShares" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RedeemableCommonStockMember" id="mirm_RedeemableCommonStockMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ReductionOfEstimatedExpensesRelatedParty" id="mirm_ReductionOfEstimatedExpensesRelatedParty" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RepurchaseAgreementsCollateralizedByDepositsAsPercentage" id="mirm_RepurchaseAgreementsCollateralizedByDepositsAsPercentage" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RoyaltyPaymentObligationsPeriod" id="mirm_RoyaltyPaymentObligationsPeriod" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SanofiAventisDeutschlandGmbHMember" id="mirm_SanofiAventisDeutschlandGmbHMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SatiogenPharmaceuticalsIncMember" id="mirm_SatiogenPharmaceuticalsIncMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ScheduleOfCashEquivalentsAndAvailableForSaleSecuritiesReconciliationTableTextBlock" id="mirm_ScheduleOfCashEquivalentsAndAvailableForSaleSecuritiesReconciliationTableTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SecuredConvertiblePromissoryNoteMember" id="mirm_SecuredConvertiblePromissoryNoteMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardBeginningDate" id="mirm_ShareBasedCompensationArrangementByShareBasedPaymentAwardBeginningDate" type="xbrli:dateItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePriceRangeLowerRangeLimit" id="mirm_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePriceRangeLowerRangeLimit" type="num:perShareItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePriceRangeUpperRangeLimit" id="mirm_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePriceRangeUpperRangeLimit" type="num:perShareItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestGrantedWeightedAverageRemainingContractualTerm1" id="mirm_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestGrantedWeightedAverageRemainingContractualTerm1" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SharesDistributedToDeferredCompensationPlanParticipants" id="mirm_SharesDistributedToDeferredCompensationPlanParticipants" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShireInternationalGmbHMember" id="mirm_ShireInternationalGmbHMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShireLicenseAgreementMember" id="mirm_ShireLicenseAgreementMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ShireProvidedServicesMember" id="mirm_ShireProvidedServicesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="StockVestedDuringPeriodSharesRestrictedCommonStockAward" id="mirm_StockVestedDuringPeriodSharesRestrictedCommonStockAward" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SummaryOfSignificantAccountingPoliciesLineItems" id="mirm_SummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="SummaryOfSignificantAccountingPoliciesTable" id="mirm_SummaryOfSignificantAccountingPoliciesTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="TemporaryEquityandStockholdersEquityNoteDisclosureTextBlock" id="mirm_TemporaryEquityandStockholdersEquityNoteDisclosureTextBlock" type="nonnum:textBlockItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TemporaryEquityIssuanceCosts" id="mirm_TemporaryEquityIssuanceCosts" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TemporaryEquityPricePerShare" id="mirm_TemporaryEquityPricePerShare" type="num:perShareItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TemporaryEquityStockIssuedDuringPeriodSharesConversionOfDebt" id="mirm_TemporaryEquityStockIssuedDuringPeriodSharesConversionOfDebt" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TemporaryEquityStockIssuedDuringPeriodSharesNewIssues" id="mirm_TemporaryEquityStockIssuedDuringPeriodSharesNewIssues" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TemporaryEquityStockIssuedDuringPeriodValueConversionOfDebt" id="mirm_TemporaryEquityStockIssuedDuringPeriodValueConversionOfDebt" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TenantImprovementAllowance" id="mirm_TenantImprovementAllowance" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TransitionServicesAgreementMember" id="mirm_TransitionServicesAgreementMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandAndEighteenEquityIncentivePlanMember" id="mirm_TwoThousandAndEighteenEquityIncentivePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandNineteenEmployeeStockPurchasePlanMember" id="mirm_TwoThousandNineteenEmployeeStockPurchasePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="TwoThousandNineteenEquityIncentivePlanMember" id="mirm_TwoThousandNineteenEquityIncentivePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UnderwritingDiscountOnPublicOffering" id="mirm_UnderwritingDiscountOnPublicOffering" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UnpaidInterest" id="mirm_UnpaidInterest" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="UpFrontPayment" id="mirm_UpFrontPayment" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="VolixibatMember" id="mirm_VolixibatMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
</schema>


