XML 41 R32.htm IDEA: XBRL DOCUMENT
v3.23.3

Significant Agreements - Additional Information (Detail) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | ---
Jul. 31, 2020 | Oct. 31, 2017 | Sep. 30, 2023 | Sep. 30, 2022 | Jun. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2016 | Mar. 31, 2023 | Mar. 31, 2007
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |
Research and development expense |  |  | $ 39,087 | $ 26,901 |  | $ 107,906 | $ 86,658 |  |  |
Allergan License Agreement Member | Vitae Pharmaceuticals Inc [Member] |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |
Potential milestone payments to be made |  | $ 99,000 |  |  |  |  |  |  |  |
Aggregate potential milestone payable |  | $ 70,000 |  |  |  |  |  |  |  |
License expiration year |  | 10 years |  |  |  |  |  |  |  |
Milestone Expenses Paid |  |  |  |  |  |  |  |  | $ 2,000 |
Development and regulaotry milestones Expenses |  |  |  |  |  |  |  |  | $ 8,000 |
UCB License Agreement [Member] | UCB Biopharma [Member] |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |
Potential milestone payments to be made |  |  |  |  |  |  |  | $ 119,500 |  |
Aggregate potential milestone payable |  |  |  |  |  |  |  | $ 250,000 |  |
License expiration year |  |  |  |  |  |  |  | 10 years |  |
Research and development expense | $ 6,000 |  |  |  |  |  |  | $ 5,000 |  |
Milestone payment payable |  |  |  |  | $ 5,800 |  |  |  |  |
License Agreement [Member] | Bayer Pharma AG [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] |  |  |  |  |  |  |  |  |  |
Aggregate payment obligation |  |  |  |  |  |  |  |  |  | $ 150,000

X
- Definition Aggregate potential milestone payable. + References No definition available. + Details
Name: | sndx_AggregatePotentialMilestonePayable
Namespace Prefix: | sndx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Development and regulaotry milestones Expenses + References No definition available. + Details
Name: | sndx_DevelopmentAndRegulaotryMilestonesExpenses
Namespace Prefix: | sndx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition License agreements expiration period. + References No definition available. + Details
Name: | sndx_LicenseAgreementsExpirationPeriod
Namespace Prefix: | sndx_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Milestone Expenses Paid + References No definition available. + Details
Name: | sndx_MilestoneExpensesPaid
Namespace Prefix: | sndx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Milestone payment due. + References No definition available. + Details
Name: | sndx_MilestonePaymentDue
Namespace Prefix: | sndx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Potential milestone payments upon achievement of milestone. + References No definition available. + Details
Name: | sndx_PotentialMilestonePaymentsUponAchievementOfMilestone
Namespace Prefix: | sndx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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 Amount of contractual obligation, including, but not limited to, long-term debt, lease obligation, purchase obligation, and other commitments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-3 + Details
Name: | us-gaap_ContractualObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 730 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482916/730-10-50-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 912 -SubTopic 730 -Name Accounting Standards Codification -Section 25 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482517/912-730-25-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481283/985-20-50-1 + Details
Name: | us-gaap_ResearchAndDevelopmentExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=sndx_AllerganLicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=sndx_UcbLicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=sndx_LicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=sndx_BayerPharmaAgMember
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: |