XML 39 R29.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Clinical Trial and Sponsored Research Agreements (City of Hope - Licenses) (Narrative) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |
Research and development - licenses acquired | $ 40 | $ 630 | $ 40 | $ 1,630
Leiden University Medical Centre [Member] |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |
Upfront fees paid | 0 | 400 | 0 | 400
Mayo Clinic [Member] |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |
Upfront fees paid | 0 | 800 | 0 | 800
CD123 (MB-102) [Member] | City of Hope National Medical Center ("COH") [Member] |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |
Non-refundable milestone payments | 0 | 300 | 0 | 300
PSCA (MB-105) [Member] | City of Hope National Medical Center ("COH") [Member] |  |  |  |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] |  |  |  |
Non-refundable milestone payments | $ 0 | $ 300 | $ 0 | $ 300

X
- Definition Non-refundable milestone payment expenses. + References No definition available. + Details
Name: | mbio_NonRefundableMilestonePayments
Namespace Prefix: | mbio_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Payment of Upfront Fees + References No definition available. + Details
Name: | mbio_PaymentOfUpfrontFees
Namespace Prefix: | mbio_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 No definition available. + Details
Name: | us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of the write-off for research and development assets that were acquired in a transaction other than a business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275 + Details
Name: | us-gaap_ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_CounterpartyNameAxis=mbio_LeidenUniversityMedicalCentreMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=mbio_MayoClinicMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mbio_Cd123ProductOrProcessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=mbio_CityOfHopeNationalMedicalCenterCohMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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