<?xml version="1.0" encoding="us-ascii"?>
<!--XBRL document created with Merrill Bridge  8.2.0.61 -->
<!--Based on XBRL 2.1-->
<!--Created on: 11/13/2018 8:19:34 AM-->
<!--Modified on: 11/13/2018 8:19:34 AM-->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef xlink:type="simple" xlink:href="ymab-20180930.xsd#StatementConsolidatedBalanceSheets" roleURI="http://www.ymabs.com/role/StatementConsolidatedBalanceSheets" />
  <roleRef xlink:type="simple" xlink:href="ymab-20180930.xsd#StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss" roleURI="http://www.ymabs.com/role/StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss" />
  <roleRef xlink:type="simple" xlink:href="ymab-20180930.xsd#StatementConsolidatedStatementsOfCashFlows" roleURI="http://www.ymabs.com/role/StatementConsolidatedStatementsOfCashFlows" />
  <roleRef xlink:type="simple" xlink:href="ymab-20180930.xsd#DisclosureAccruedLiabilitiesDetails" roleURI="http://www.ymabs.com/role/DisclosureAccruedLiabilitiesDetails" />
  <calculationLink xlink:role="http://www.ymabs.com/role/StatementConsolidatedBalanceSheets" xlink:type="extended" xlink:title="00100 - Statement - Consolidated Balance Sheets">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent_636776939740516709" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_AssetsCurrent_636776939740516709" order="1" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_636776939740526710" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_636776939740516709" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_636776939740526710" order="1" use="optional" weight="1" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RestrictedCashCurrent" xlink:label="us-gaap_RestrictedCashCurrent_636776939740526710" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_636776939740516709" xlink:to="us-gaap_RestrictedCashCurrent_636776939740526710" order="2" use="optional" weight="1" priority="4" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="us-gaap_OtherAssetsCurrent_636776939740526710" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_636776939740516709" xlink:to="us-gaap_OtherAssetsCurrent_636776939740526710" order="3" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_636776939740526710" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_636776939740526710" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredOfferingCosts" xlink:label="us-gaap_DeferredOfferingCosts_636776939740526710" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_DeferredOfferingCosts_636776939740526710" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent_636776939740526710" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_OtherAssetsNoncurrent_636776939740526710" order="4" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_Liabilities_636776939740626720" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities_636776939740626720" xlink:to="us-gaap_LiabilitiesCurrent_636776939740626720" order="1" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_636776939740626720" xlink:to="us-gaap_AccountsPayableCurrent_636776939740626720" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_636776939740626720" xlink:to="us-gaap_AccruedLiabilitiesCurrent_636776939740626720" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="ymab-20180930.xsd#ymab_AccruedMilestoneAndRoyaltyPaymentsNoncurrent" xlink:label="ymab_AccruedMilestoneAndRoyaltyPaymentsNoncurrent_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities_636776939740626720" xlink:to="ymab_AccruedMilestoneAndRoyaltyPaymentsNoncurrent_636776939740626720" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_CommitmentsAndContingencies_636776939740626720" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_StockholdersEquity_636776939740626720" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636776939740626720" xlink:to="us-gaap_PreferredStockValue_636776939740626720" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636776939740626720" xlink:to="us-gaap_CommonStockValue_636776939740626720" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636776939740626720" xlink:to="us-gaap_AdditionalPaidInCapital_636776939740626720" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636776939740626720" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_636776939740626720" order="4" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_636776939740626720" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636776939740626720" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_636776939740626720" order="5" use="optional" weight="1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.ymabs.com/role/StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss" xlink:type="extended" xlink:title="00200 - Statement - Consolidated Statements of Net Loss and Comprehensive Loss">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_636776939740636721" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_NetIncomeLoss_636776939740636721" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss_636776939740636721" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_636776939740636721" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss_636776939740636721" xlink:to="us-gaap_OperatingIncomeLoss_636776939740636721" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss_636776939740636721" xlink:to="us-gaap_OperatingExpenses_636776939740636721" order="1" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses_636776939740636721" xlink:to="us-gaap_ResearchAndDevelopmentExpense_636776939740636721" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses_636776939740636721" xlink:to="us-gaap_GeneralAndAdministrativeExpense_636776939740636721" order="2" use="optional" weight="1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.ymabs.com/role/StatementConsolidatedStatementsOfCashFlows" xlink:type="extended" xlink:title="00400 - Statement - Consolidated Statements of Cash Flows">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" order="1" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="us-gaap_ProfitLoss_636776939740636721" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="us-gaap_DepreciationDepletionAndAmortization_636776939740636721" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="us-gaap_ShareBasedCompensation_636776939740636721" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="ymab-20180930.xsd#ymab_NoncashStockIssuanceCostsToStrategicPartner" xlink:label="ymab_NoncashStockIssuanceCostsToStrategicPartner_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="ymab_NoncashStockIssuanceCostsToStrategicPartner_636776939740636721" order="4" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_636776939740636721" order="5" use="optional" weight="-1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInOtherCurrentAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherCurrentAssets_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="us-gaap_IncreaseDecreaseInOtherCurrentAssets_636776939740636721" order="6" use="optional" weight="-1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherNoncurrentAssets_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="us-gaap_IncreaseDecreaseInOtherNoncurrentAssets_636776939740636721" order="7" use="optional" weight="-1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_636776939740636721" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable_636776939740636721" order="8" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="ymab-20180930.xsd#ymab_IncreaseDecreaseInAccruedLiabilitiesAndOther" xlink:label="ymab_IncreaseDecreaseInAccruedLiabilitiesAndOther_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636776939740636721" xlink:to="ymab_IncreaseDecreaseInAccruedLiabilitiesAndOther_636776939740646722" order="9" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_636776939740646722" order="2" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_636776939740646722" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_636776939740646722" order="1" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_636776939740646722" order="3" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_636776939740646722" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_636776939740646722" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_636776939740646722" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts_636776939740646722" order="2" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_636776939740646722" order="4" use="optional" weight="1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.ymabs.com/role/DisclosureAccruedLiabilitiesDetails" xlink:type="extended" xlink:title="40501 - Disclosure - ACCRUED LIABILITIES (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent_636748512224559268" />
    <loc xlink:type="locator" xlink:href="ymab-20180930.xsd#ymab_AccruedClinicalCostsCurrent" xlink:label="ymab_AccruedClinicalCostsCurrent_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent_636748512224559268" xlink:to="ymab_AccruedClinicalCostsCurrent_636776939740646722" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="ymab-20180930.xsd#ymab_AccruedCompensationAndBoardFeesCurrent" xlink:label="ymab_AccruedCompensationAndBoardFeesCurrent_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent_636748512224559268" xlink:to="ymab_AccruedCompensationAndBoardFeesCurrent_636776939740646722" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="ymab-20180930.xsd#ymab_AccruedMilestonePaymentsCurrent" xlink:label="ymab_AccruedMilestonePaymentsCurrent_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent_636748512224559268" xlink:to="ymab_AccruedMilestonePaymentsCurrent_636776939740646722" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_636776939740646722" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent_636748512224559268" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent_636776939740646722" order="4" use="optional" weight="1" priority="2" />
  </calculationLink>
</linkbase>
