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  <xsd:element name="OperatingLossCarryforwardsAnnualLimitationAmount" id="cldx_OperatingLossCarryforwardsAnnualLimitationAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="OperatingLossCarryforwardsNetOfExpirationsAndUtilization" id="cldx_OperatingLossCarryforwardsNetOfExpirationsAndUtilization" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="OperatingLossCarryforwardsWithLimitationsOnUse" id="cldx_OperatingLossCarryforwardsWithLimitationsOnUse" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="OperatingLossCarryforwardsRemotelyLikelyToBeUtilized" id="cldx_OperatingLossCarryforwardsRemotelyLikelyToBeUtilized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="OwnershipChangeAxis" id="cldx_OwnershipChangeAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OwnershipChangeDomain" id="cldx_OwnershipChangeDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OwnershipChangeInOctober2007Member" id="cldx_OwnershipChangeInOctober2007Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OwnershipChangesInJune2009AndDecember2009Member" id="cldx_OwnershipChangesInJune2009AndDecember2009Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="PeriodOfRecognitionOfUnrealizedGainLossAfterOwnershipChange" id="cldx_PeriodOfRecognitionOfUnrealizedGainLossAfterOwnershipChange" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="PriorToAcquisitionMember" id="cldx_PriorToAcquisitionMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="PriorToMergerMember" id="cldx_PriorToMergerMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="StatusOfMergerAndAcquisitionAxis" id="cldx_StatusOfMergerAndAcquisitionAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="StatusOfMergerAndAcquisitionDomain" id="cldx_StatusOfMergerAndAcquisitionDomain" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TaxCreditCarryforwardAmountWithSubstantialLimitationsOnUse" id="cldx_TaxCreditCarryforwardAmountWithSubstantialLimitationsOnUse" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="OperatingLossAndTaxCreditCarryforwardsTable" id="cldx_OperatingLossAndTaxCreditCarryforwardsTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="CollaborativeArrangementForDevelopmentAndCommercializationOfProductMember" id="cldx_CollaborativeArrangementForDevelopmentAndCommercializationOfProductMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="RoyaltyAgreementMember" id="cldx_RoyaltyAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="CincinnatiChildrensHospitalMedicalCenterMember" id="cldx_CincinnatiChildrensHospitalMedicalCenterMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ExpirationOfNetOperatingLossesAndResearchAndDevelopmentTaxCredits" id="cldx_ExpirationOfNetOperatingLossesAndResearchAndDevelopmentTaxCredits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="ValueAtWhichTaxBenefitsSold" id="cldx_ValueAtWhichTaxBenefitsSold" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="FairValueAssetsAmountTransfersBetweenMeasurementLevels" id="cldx_FairValueAssetsAmountTransfersBetweenMeasurementLevels" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="FairValueLiabilitiesAmountTransfersBetweenMeasurementLevels" id="cldx_FairValueLiabilitiesAmountTransfersBetweenMeasurementLevels" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="AvailableForSaleSecuritiesConsideredToBeOtherThanTemporarilyImpaired" id="cldx_AvailableForSaleSecuritiesConsideredToBeOtherThanTemporarilyImpaired" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="AccumulatedOtherComprehensiveIncomeLossRollForward" id="cldx_AccumulatedOtherComprehensiveIncomeLossRollForward" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="RepaymentOfLongTermDebtPrincipalAmount" id="cldx_RepaymentOfLongTermDebtPrincipalAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="DebtInstrumentInterestAndPrepaymentFees" id="cldx_DebtInstrumentInterestAndPrepaymentFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="IncomeTaxExpenseBenefitBeforeChangeInValuationAllowance" id="cldx_IncomeTaxExpenseBenefitBeforeChangeInValuationAllowance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="CollaborativeArrangementEstimatedCostForDevelopmentServices" id="cldx_CollaborativeArrangementEstimatedCostForDevelopmentServices" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="CollaborativeArrangementUpfrontPaymentAmount" id="cldx_CollaborativeArrangementUpfrontPaymentAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="CelldexResearchEquityIncentivePlan2005AndCuraGenStockPlan2007Member" id="cldx_CelldexResearchEquityIncentivePlan2005AndCuraGenStockPlan2007Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="DeferredTaxAssetsOperatingLossCarryforwardsNotYetUtilized" id="cldx_DeferredTaxAssetsOperatingLossCarryforwardsNotYetUtilized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="ExpectedDividendPayableInForeseeableFuture" id="cldx_ExpectedDividendPayableInForeseeableFuture" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="ReimbursementOfExternalCostsIncurredPercentage" id="cldx_ReimbursementOfExternalCostsIncurredPercentage" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="BiosynCorporationMember" id="cldx_BiosynCorporationMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="GlembatumumabVedotinMember" id="cldx_GlembatumumabVedotinMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="Cdx014Member" id="cldx_Cdx014Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfOtherLongTermLiabilitiesTableTextBlock" id="cldx_ScheduleOfOtherLongTermLiabilitiesTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <element id="cldx_BristolMeyersSquibbCompanyMember" name="BristolMeyersSquibbCompanyMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
</xsd:schema>
