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  <xs:element id="regn_AcquiredInProcessResearchAndDevelopmentAssetAcquisition" abstract="false" name="AcquiredInProcessResearchAndDevelopmentAssetAcquisition" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="regn_SalesMilestoneThreeMember" abstract="true" name="SalesMilestoneThreeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="regn_JosephLGoldsteinMDMember" abstract="true" name="JosephLGoldsteinMDMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="regn_RocheCollaborationAgreementMember" abstract="true" name="RocheCollaborationAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="regn_NumberOfInterPartiesReviewIPRPetitionsFiled" abstract="false" name="NumberOfInterPartiesReviewIPRPetitionsFiled" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="regn_AssetAcquisitionContingentConsiderationAccruedButNotYetPaid" abstract="false" name="AssetAcquisitionContingentConsiderationAccruedButNotYetPaid" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="regn_CollaborationandContractManufacturingMember" abstract="true" name="CollaborationandContractManufacturingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="regn_PaymentToCollaboratingParty" abstract="false" name="PaymentToCollaboratingParty" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="regn_MilestoneTypeAxis" abstract="true" name="MilestoneTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="regn_SanofiMember" abstract="true" name="SanofiMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="regn_PaymentsToAcquireBusinessesGrossAndPaymentsToSuppliers" abstract="false" name="PaymentsToAcquireBusinessesGrossAndPaymentsToSuppliers" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="regn_LevelsOfTwelveMonthSalesAtWhichSalesMilestonePaymentsWouldBeReceived" abstract="false" name="LevelsOfTwelveMonthSalesAtWhichSalesMilestonePaymentsWouldBeReceived" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="regn_SalesMilestoneFiveMember" abstract="true" name="SalesMilestoneFiveMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="regn_ReimbursementForManufacturingOfCommercialSuppliesMember" abstract="true" name="ReimbursementForManufacturingOfCommercialSuppliesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="regn_RevenueRemainingPerformanceObligationVariableConsiderationAmount" abstract="false" name="RevenueRemainingPerformanceObligationVariableConsiderationAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="regn_PraluentNetProductSalesMember" abstract="true" name="PraluentNetProductSalesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
</xs:schema>
