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  <xs:element id="lxrx_DebtFundingTrancheAxis" abstract="true" name="DebtFundingTrancheAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="lxrx_DebtFundingPeriodDomain" abstract="true" name="DebtFundingPeriodDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lxrx_DebtTrancheOneMember" abstract="true" name="DebtTrancheOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lxrx_DebtTrancheTwoMember" abstract="true" name="DebtTrancheTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lxrx_DebtTrancheThreeMember" abstract="true" name="DebtTrancheThreeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lxrx_LineOfCreditFacilityExitFeePercentage" abstract="false" name="LineOfCreditFacilityExitFeePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lxrx_LineOfCreditFacilityPrepaymentFeePercentage" abstract="false" name="LineOfCreditFacilityPrepaymentFeePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lxrx_ClassOfWarrantOrRightThresholdPercentageOfCommonStockShares" abstract="false" name="ClassOfWarrantOrRightThresholdPercentageOfCommonStockShares" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lxrx_DebtInstrumentInterestRateOnlyPeriod" abstract="false" name="DebtInstrumentInterestRateOnlyPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="lxrx_DebtInstrumentInterestRateOnlyPeriodRenewalTermOne" abstract="false" name="DebtInstrumentInterestRateOnlyPeriodRenewalTermOne" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="lxrx_DebtInstrumentInterestRateOnlyPeriodRenewalTermTwo" abstract="false" name="DebtInstrumentInterestRateOnlyPeriodRenewalTermTwo" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="lxrx_DebtInstrumentVariableInterestRateFloor" abstract="false" name="DebtInstrumentVariableInterestRateFloor" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lxrx_DebtInstrumentCovenantComplianceCashAndInvestmentsBalanceMinimum" abstract="false" name="DebtInstrumentCovenantComplianceCashAndInvestmentsBalanceMinimum" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lxrx_EmployeesMember" abstract="true" name="EmployeesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lxrx_OfficersAndNonEmployeeDirectorsMember" abstract="true" name="OfficersAndNonEmployeeDirectorsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lxrx_PublicOfferingMember" abstract="true" name="PublicOfferingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lxrx_ConvertiblePreferredStockAggregateSharesIssuedUponConversion" abstract="false" name="ConvertiblePreferredStockAggregateSharesIssuedUponConversion" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="lxrx_ReportableSegmentMember" abstract="true" name="ReportableSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
