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    <element id="pktx_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpiredInPeriodWeightedAverageExpiredDateFairValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpiredInPeriodWeightedAverageExpiredDateFairValue" nillable="true" xbrli:periodType="duration" type="num:perShareItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_ExpectedForfeitureRate" name="ExpectedForfeitureRate" nillable="true" xbrli:periodType="duration" type="num:percentItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_ClassOfWarrantOrRightsExercisePrice" name="ClassOfWarrantOrRightsExercisePrice" nillable="true" xbrli:periodType="instant" type="num:perShareItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_ExpiryDateOfWarrant" name="ExpiryDateOfWarrant" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_PatentApplicationRightsMember" name="PatentApplicationRightsMember" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_Date3Member" name="Date3Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_Date4Member" name="Date4Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_Date1Member" name="Date1Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_Date9Member" name="Date9Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_Date11Member" name="Date11Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_Date12Member" name="Date12Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_August312021Member" name="August312021Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_Date2Member" name="Date2Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_Date6Member" name="Date6Member" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
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    <element id="pktx_WarrantTwoMember" name="WarrantTwoMember" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_InvestorsMember" name="InvestorsMember" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
    <element id="pktx_ClarenceSmithCEOMember" name="ClarenceSmithCEOMember" nillable="true" xbrli:periodType="duration" type="nonnum:domainItemType" substitutionGroup="xbrli:item" />
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    <element id="pktx_PrepaidExpensesAndDepositsTablesAbstract" name="PrepaidExpensesAndDepositsTablesAbstract" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
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    <element id="pktx_NotesToFinancialStatementsAbstract" name="NotesToFinancialStatementsAbstract" abstract="true" nillable="true" xbrli:periodType="duration" type="xbrli:stringItemType" substitutionGroup="xbrli:item" />
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</schema>


