XML 40 R34.htm IDEA: XBRL DOCUMENT
v3.24.3

Collaborations - Additional Information (Details) $ / shares in Units, € in Millions |  |  |  |  | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 05, 2024 USD ($) $ / shares shares | Jan. 18, 2021 USD ($) $ / shares shares | Mar. 14, 2018 EUR (€) | Jan. 23, 2017 USD ($) | Jul. 31, 2024 USD ($) | Jan. 31, 2022 | Sep. 30, 2024 USD ($) Milestone | Jun. 30, 2024 USD ($) | Mar. 31, 2024 USD ($) | Sep. 30, 2024 USD ($) Milestone | Sep. 30, 2023 USD ($) | Dec. 31, 2022 USD ($) | Apr. 30, 2024 USD ($) | Feb. 12, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of common stock, net |  |  |  |  |  |  |  |  |  | $ 434,863,000 | $ 225,945,000 |  |  |
Development milestones achieved |  |  |  |  |  |  |  |  |  | $ 0 |  |  |  |
Lilly Collaborations Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-refundable upfront payment receivable |  | $ 40,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common share, net, shares | shares |  | 706,834 |  |  |  |  |  |  |  |  |  |  |  |
Common shares stated purchase price per share | $ / shares |  | $ 28.295 |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of common stock, net |  | $ 20,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Fixed consideration |  | 43,500,000 |  |  |  |  |  |  |  |  |  |  |  | $ 43,500,000
Fee incurred for extension of research term |  |  |  |  |  |  |  |  |  |  |  | $ 500,000 |  |
Extension fee payment of research term received |  |  |  |  | $ 500,000 |  |  |  |  |  |  |  |  |
Upfront payment |  | 40,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Net fair value of shares |  | $ 16,500,000 |  |  |  |  |  |  |  |  |  |  |  |
Number of milestones achieved | Milestone |  |  |  |  |  |  | 0 |  |  | 0 |  |  |  |
Incyte Collaboration and License Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Development milestones achieved |  |  |  |  |  |  | $ 0 | $ 0 | $ 1,000,000 |  |  |  |  |
Incyte Collaboration and License Agreement | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Residual royalty percentage |  |  |  |  |  | 4.00% |  |  |  |  |  |  |  |
Incyte Collaboration and License Agreement | License and Related Activities |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborations, transaction price as deferred revenue |  |  |  | $ 152,600,000 |  |  |  |  |  |  |  |  |  |
Second ONO Research and License Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-refundable upfront payment receivable | € |  |  | € 0.7 |  |  |  |  |  |  |  |  |  |  |
Payment to compensate research services | € |  |  | 0.3 |  |  |  |  |  |  |  |  |  |  |
Over time payment for full time equivalent funding | € |  |  | € 0.2 |  |  |  |  |  |  |  |  |  |  |
Development milestones achieved |  |  |  |  |  |  | $ 2 |  |  |  |  |  |  |
Gilead Collaboration Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-refundable upfront payment receivable | $ 56,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common share, net, shares | shares | 452,527 |  |  |  |  |  |  |  |  |  |  |  |  |
Common shares stated purchase price per share | $ / shares | $ 55.2454 |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of common stock, net | $ 25,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed consideration | 58,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Net fair value of shares | 22,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Non-refundable upfront payment received |  |  |  |  |  |  |  |  |  |  |  |  | $ 56,000,000 |
Number of milestones achieved | Milestone |  |  |  |  |  |  | 0 |  |  | 0 |  |  |  |
Non-refundable upfront initiation fee | 28,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
License option exercise fee | $ 10,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Deferred revenue from collaborative arrangement. + References No definition available. + Details
Name: | mrus_DeferredRevenueFromCollaborativeArrangement
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Development milestones achieved. + References No definition available. + Details
Name: | mrus_DevelopmentMilestonesAchieved
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Extension fee payment of research term received. + References No definition available. + Details
Name: | mrus_ExtensionFeePaymentOfResearchTermReceived
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fee Incurred For Extension Of Research Term + References No definition available. + Details
Name: | mrus_FeeIncurredForExtensionOfResearchTerm
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition License option exercise fee. + References No definition available. + Details
Name: | mrus_LicenseOptionExerciseFee
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Non refundable upfront initiation fee. + References No definition available. + Details
Name: | mrus_NonRefundableUpfrontInitiationFee
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Non refundable upfront payments receivable. + References No definition available. + Details
Name: | mrus_NonRefundableUpfrontPaymentsReceivable
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Non-refundable upfront payments received. + References No definition available. + Details
Name: | mrus_NonRefundableUpfrontPaymentsReceived
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of milestones achieved. + References No definition available. + Details
Name: | mrus_NumberOfMilestonesAchieved
Namespace Prefix: | mrus_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Over time payment for full time equivalent funding. + References No definition available. + Details
Name: | mrus_OverTimePaymentForFullTimeEquivalentFunding
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Payment to compensate research services. + References No definition available. + Details
Name: | mrus_PaymentToCompensateResearchServices
Namespace Prefix: | mrus_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Residual royalty percentage. + References No definition available. + Details
Name: | mrus_ResidualRoyaltyPercentage
Namespace Prefix: | mrus_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 808 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479402/808-10-50-1 + Details
Name: | us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Cash received from collaborators during the current period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 25 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-25 + Details
Name: | us-gaap_ProceedsFromCollaborators
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 14 -Subparagraph (a) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-14 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of transaction price allocated to performance obligation that has not been recognized as revenue. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -SubTopic 10 -Topic 606 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479806/606-10-50-13 + Details
Name: | us-gaap_RevenueRemainingPerformanceObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Per share or per unit amount of equity securities issued. + References No definition available. + Details
Name: | us-gaap_SharesIssuedPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of new stock issued during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478448/946-505-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(i)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479168/946-830-55-11 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 205 -Name Accounting Standards Codification -Section 45 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478009/946-205-45-4 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478448/946-505-50-2 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_StockRepurchasedDuringPeriodValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=mrus_LillyCollaborationsAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=mrus_IncyteCollaborationAndLicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mrus_LicenseAndRelatedActivitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=mrus_SecondONOResearchAndLicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=mrus_GileadCollaborationAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |