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  <xsd:element id="hrmy_IntellectualPropertyPaymentDueUponAchievementOfRegulatoryMilestones" name="IntellectualPropertyPaymentDueUponAchievementOfRegulatoryMilestones" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="hrmy_IntellectualPropertyPaymentDueUponAchievementOfDevelopmentalMilestones" name="IntellectualPropertyPaymentDueUponAchievementOfDevelopmentalMilestones" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="hrmy_IntellectualPropertyPaymentDueUponAchievementOfSalesMilestones" name="IntellectualPropertyPaymentDueUponAchievementOfSalesMilestones" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="hrmy_BlackstoneAlternativeCreditAdvisorsMember" name="BlackstoneAlternativeCreditAdvisorsMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element name="OperatingLeaseAssetAbstract" id="hrmy_OperatingLeaseAssetAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ShareBasedCompensationPercentageOfIncrementInCommonStockOutstandingAnnually" id="hrmy_ShareBasedCompensationPercentageOfIncrementInCommonStockOutstandingAnnually" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="NdaForWakixMember" id="hrmy_NdaForWakixMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DaytimeSleepinessMember" id="hrmy_DaytimeSleepinessMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CataplexyMember" id="hrmy_CataplexyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LicenseAgreementFinalPaymentPaid" id="hrmy_LicenseAgreementFinalPaymentPaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LongTermInvestmentsMember" id="hrmy_LongTermInvestmentsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="NonCurrentInvestmentMaturityTerm" id="hrmy_NonCurrentInvestmentMaturityTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="LicenseAndAssetPurchaseAgreementsAbstract" id="hrmy_LicenseAndAssetPurchaseAgreementsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LicenseAndAssetPurchaseAgreementsTextBlock" id="hrmy_LicenseAndAssetPurchaseAgreementsTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="LicenseAndAssetPurchaseAgreementsTable" id="hrmy_LicenseAndAssetPurchaseAgreementsTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LicenseAndAssetPurchaseAgreementsLineItems" id="hrmy_LicenseAndAssetPurchaseAgreementsLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ShortTermCommercialPaperMember" id="hrmy_ShortTermCommercialPaperMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ShortTermCorporateDebtSecuritiesMember" id="hrmy_ShortTermCorporateDebtSecuritiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LongTermCorporateDebtSecuritiesMember" id="hrmy_LongTermCorporateDebtSecuritiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ShortTermUsGovernmentSecuritiesMember" id="hrmy_ShortTermUsGovernmentSecuritiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LongTermUsGovernmentSecuritiesMember" id="hrmy_LongTermUsGovernmentSecuritiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ConcentrationsOfRiskNumberOfFinancialInstitutions" id="hrmy_ConcentrationsOfRiskNumberOfFinancialInstitutions" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="LicenseAgreementUpfrontNonRefundableFeePaid" id="hrmy_LicenseAgreementUpfrontNonRefundableFeePaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LicenseAgreementMaximumAdditionalMilestonePaymentsDue" id="hrmy_LicenseAgreementMaximumAdditionalMilestonePaymentsDue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LongTermCommercialPaperMember" id="hrmy_LongTermCommercialPaperMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="SalesBasedTrademarkAndTieredRoyaltiesMember" id="hrmy_SalesBasedTrademarkAndTieredRoyaltiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LicenseAgreementPreclinicalMilestonePaymentsRecognized" id="hrmy_LicenseAgreementPreclinicalMilestonePaymentsRecognized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="OperatingLeaseAdditionalOfficeSpaceLeasedOne" id="hrmy_OperatingLeaseAdditionalOfficeSpaceLeasedOne" type="dtr-types:areaItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="OperatingLeaseAdditionalOfficeSpaceLeasedTwo" id="hrmy_OperatingLeaseAdditionalOfficeSpaceLeasedTwo" type="dtr-types:areaItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="StockIssuedDuringPeriodValueStockOptionsAndRestrictedStockUnitsExercised" id="hrmy_StockIssuedDuringPeriodValueStockOptionsAndRestrictedStockUnitsExercised" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="StockIssuedDuringPeriodSharesStockOptionsAndRestrictedStockUnitsExercised" id="hrmy_StockIssuedDuringPeriodSharesStockOptionsAndRestrictedStockUnitsExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="LondonInterbankOfferedRateMember" id="hrmy_LondonInterbankOfferedRateMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CommonStockNumberOfVotesPerShare" id="hrmy_CommonStockNumberOfVotesPerShare" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="FiveYearSeniorSecuredTermLoanMember" id="hrmy_FiveYearSeniorSecuredTermLoanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="RepaymentPremiumPercentage" id="hrmy_RepaymentPremiumPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
</xsd:schema>
