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  <xsd:element name="SummaryOfSignificantAccountingPoliciesTable" id="cldx_SummaryOfSignificantAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="SummaryOfSignificantAccountingPoliciesLineItems" id="cldx_SummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ControlledEquityOfferingSalesAgreementMember" id="cldx_ControlledEquityOfferingSalesAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ExpectedDividendPayments" id="cldx_ExpectedDividendPayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="LicenseAgreementWithYaleMember" id="cldx_LicenseAgreementWithYaleMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="RockefellerUniversityMember" id="cldx_RockefellerUniversityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
</xsd:schema>
