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  <element id="cldx_ContractAssetsAndLiabilitiesPolicyTextBlock" name="ContractAssetsAndLiabilitiesPolicyTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="cldx_OtherAssetsPolicyTextBlock" name="OtherAssetsPolicyTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="cldx_PatentCostsPolicyTextBlock" name="PatentCostsPolicyTextBlock" nillable="true" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
  <element id="cldx_CombinedRockefellerUniversityAndGileadSciencesMember" name="CombinedRockefellerUniversityAndGileadSciencesMember" nillable="true" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" xmlns="http://www.w3.org/2001/XMLSchema" />
</xsd:schema>
