$SNDX
Syndax Pharmaceuticals Inc Stock $sndx

$sndx Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000095017024021253 Filed on February 27, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$0.00	$0.00	$0.00
YoY Change
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin	$23.02M	$22.78M	$66.92M
YoY Change	92.48%	123.5%	101.22%
% of Gross Profit
Research & Development	$56.49M	$55.13M	$163.0M
YoY Change	65.89%	73.13%	37.58%
% of Gross Profit
Depreciation & Amortization	$3.000K	$3.000K	$12.00M
YoY Change	0.0%	0.0%	-63.64%
% of Gross Profit
Operating Expenses	$79.51M	$77.91M	$230.0M
YoY Change	72.8%	85.34%	51.53%
Operating Profit	-$79.51M		-$230.0M
YoY Change	72.8%		51.53%
Interest Expense	$55.00K	$5.487M	$208.0K
YoY Change	37.5%	86.32%	-93.37%
% of Operating Profit
Other Income/Expense, Net	$7.114M	-$55.00K	$20.59M
YoY Change	45.51%	-48.11%	751.34%
Pretax Income	-$72.40M	-$72.47M	-$209.4M
YoY Change	76.04%	84.91%	40.19%
Income Tax
% Of Pretax Income
Net Earnings	-$72.40M	-$72.47M	-$209.4M
YoY Change	76.04%	84.91%	40.19%
Net Earnings / Revenue
Basic Earnings Per Share	-$0.85		-$2.98
Diluted Earnings Per Share	-$0.85	-$1.00	-$2.98
COMMON SHARES
Basic Shares Outstanding	84.97M	69.64M	70.37M
Diluted Shares Outstanding	85.21M		70.37M

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments	$443.2M	$577.6M	$577.6M
YoY Change	1.13%	19.24%	19.24%
Cash & Equivalents	$114.6M	$295.4M	$295.4M
Short-Term Investments	$328.5M	$282.2M	$282.2M
Other Short-Term Assets	$6.073M	$2.066M	$2.066M
YoY Change	392.14%	55.11%	55.11%
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets	$453.9M	$580.9M	$580.9M
YoY Change	2.81%	18.6%	18.6%
LONG-TERM ASSETS
Property, Plant & Equipment	$5.000K	$8.000K	$1.495M
YoY Change	-70.59%	-60.0%	41.17%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$87.42M	$29.83M	$29.83M
YoY Change	427.84%	445.42%	445.42%
Other Assets	$248.0K	$463.0K	$680.0K
YoY Change	-64.21%	-42.63%	-26.25%
Total Long-Term Assets	$89.13M	$32.00M	$32.00M
YoY Change	386.64%	329.58%	329.58%
TOTAL ASSETS
Total Short-Term Assets	$453.9M	$580.9M	$580.9M
Total Long-Term Assets	$89.13M	$32.00M	$32.00M
Total Assets	$543.0M	$612.9M	$612.9M
YoY Change	18.09%	23.26%	23.26%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$8.809M	$9.961M	$9.961M
YoY Change	9.33%	128.99%	128.99%
Accrued Expenses	$34.44M	$40.89M	$40.89M
YoY Change	119.92%	65.48%	65.48%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$12.00K	$12.00K	$12.00K
YoY Change	140.0%	140.0%	140.0%
Total Short-Term Liabilities	$50.81M	$58.10M	$58.10M
YoY Change	114.18%	99.88%	99.88%
LONG-TERM LIABILITIES
Long-Term Debt	$7.000K	$10.00K	$10.00K
YoY Change	-41.67%	-23.08%	-23.08%
Other Long-Term Liabilities	$327.0K	$578.0K	$578.0K
YoY Change	-44.39%	-18.48%	-18.48%
Total Long-Term Liabilities	$334.0K	$588.0K	$588.0K
YoY Change	-44.33%	-18.56%	-18.56%
TOTAL LIABILITIES
Total Short-Term Liabilities	$50.81M	$58.10M	$58.10M
Total Long-Term Liabilities	$334.0K	$588.0K	$588.0K
Total Liabilities	$51.14M	$58.68M	$58.68M
YoY Change	110.27%	97.01%	97.01%
SHAREHOLDERS EQUITY
Retained Earnings	-$974.8M	-$902.4M
YoY Change	32.78%	30.21%
Common Stock	$1.467B	$1.456B
YoY Change	25.42%	25.41%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$491.9M	$554.2M	$554.2M
YoY Change
Total Liabilities & Shareholders Equity	$543.0M	$612.9M	$612.9M
YoY Change	18.09%	23.26%	23.26%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	-$72.40M	-$72.47M	-$209.4M
YoY Change	76.04%	84.91%	40.19%
Depreciation, Depletion And Amortization	$3.000K	$3.000K	$12.00M
YoY Change	0.0%	0.0%	-63.64%
Cash From Operating Activities	-$83.55M	-$41.35M	-$160.6M
YoY Change	112.98%	80.61%	20.14%
INVESTING ACTIVITIES
Capital Expenditures		$0.00	$0.00
YoY Change
Acquisitions
YoY Change
Other Investing Activities	-$99.40M	-$16.29M	$117.6M
YoY Change	-599.12%	-88.16%	-163.17%
Cash From Investing Activities	-$99.40M	-$16.29M	$117.6M
YoY Change	-599.12%	-88.16%	-163.17%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	2.168M	258.5M	264.1M
YoY Change	-12.37%	58.09%	53.34%
NET CHANGE
Cash From Operating Activities	-83.55M	-41.35M	-160.6M
Cash From Investing Activities	-99.40M	-16.29M	117.6M
Cash From Financing Activities	2.168M	258.5M	264.1M
Net Change In Cash	-180.8M	200.8M	221.1M
YoY Change	973.57%	6641.99%	-249.81%
FREE CASH FLOW
Cash From Operating Activities	-$83.55M	-$41.35M	-$160.6M
Capital Expenditures		$0.00	$0.00
Free Cash Flow		-$41.35M	-$160.6M
YoY Change		80.61%	20.14%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value
CY2022	us-gaap	Lessee Operating Lease Existence Of Option To Extend LesseeOperatingLeaseExistenceOfOptionToExtend	true
CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies
CY2023	dei	Amendment Flag AmendmentFlag	false
CY2023	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2022	us-gaap	Lessee Operating Lease Existence Of Option To Terminate LesseeOperatingLeaseExistenceOfOptionToTerminate	true
CY2023	dei	Entity Central Index Key EntityCentralIndexKey	0001395937
CY2022Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies
CY2023	us-gaap	Type Of Revenue Extensible List TypeOfRevenueExtensibleList	http://fasb.org/us-gaap/2023#LicenseMember
CY2022	us-gaap	Type Of Revenue Extensible List TypeOfRevenueExtensibleList	http://fasb.org/us-gaap/2023#LicenseMember
CY2021	us-gaap	Type Of Revenue Extensible List TypeOfRevenueExtensibleList	http://fasb.org/us-gaap/2023#LicenseMember
CY2023	dei	Document Type DocumentType	10-K
CY2023	dei	Document Annual Report DocumentAnnualReport	true
CY2023	dei	Document Period End Date DocumentPeriodEndDate	2023-12-31
CY2023	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2023
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	001-37708
CY2023	dei	Entity Registrant Name EntityRegistrantName	Syndax Pharmaceuticals, Inc.
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	32-0162505
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	35 Gatehouse Drive
CY2023	dei	Entity Address Address Line2 EntityAddressAddressLine2	Building D
CY2023	dei	Entity Address Address Line3 EntityAddressAddressLine3	Floor 3
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	Waltham
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	MA
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	02451
CY2023	dei	City Area Code CityAreaCode	781
CY2023	dei	Local Phone Number LocalPhoneNumber	419-1400
CY2023	dei	Security12b Title Security12bTitle	Common Stock
CY2023	dei	Trading Symbol TradingSymbol	SNDX
CY2023	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2023	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2023	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2023	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2023	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2023	dei	Entity Small Business EntitySmallBusiness	false
CY2023	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2023	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2023	dei	Document Fin Stmt Error Correction Flag DocumentFinStmtErrorCorrectionFlag	false
CY2023	dei	Entity Shell Company EntityShellCompany	false
CY2023Q2	dei	Entity Public Float EntityPublicFloat	1452441662000
CY2024Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	84965486
CY2023	dei	Auditor Firm AuditorFirmId	34
CY2023	dei	Auditor Name AuditorName	Deloitte & Touche LLP
CY2023	dei	Auditor Location AuditorLocation	New York, New York
CY2023Q4	ecd	Non Rule10b51 Arr Adopted Flag NonRule10b51ArrAdoptedFlag	false
CY2023Q4	ecd	Rule10b51 Arr Adopted Flag Rule10b51ArrAdoptedFlag	false
CY2023Q4	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false
CY2023Q4	ecd	Rule10b51 Arr Trmntd Flag Rule10b51ArrTrmntdFlag	false
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	295394000
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	74356000
CY2023Q4	us-gaap	Short Term Investments ShortTermInvestments	275304000
CY2022Q4	us-gaap	Short Term Investments ShortTermInvestments	401446000
CY2023Q4	us-gaap	Deposits Assets Current DepositsAssetsCurrent	6885000
CY2022Q4	us-gaap	Deposits Assets Current DepositsAssetsCurrent	8595000
CY2023Q4	sndx	Collaboration Receivable CollaborationReceivable	0
CY2022Q4	sndx	Collaboration Receivable CollaborationReceivable	3474000
CY2023Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	3293000
CY2022Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	1915000
CY2023Q4	us-gaap	Assets Current AssetsCurrent	580876000
CY2022Q4	us-gaap	Assets Current AssetsCurrent	489786000
CY2023Q4	us-gaap	Long Term Investments LongTermInvestments	29829000
CY2022Q4	us-gaap	Long Term Investments LongTermInvestments	5469000
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	8000
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	20000
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	1487000
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	1039000
CY2023Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	217000
CY2022Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	115000
CY2023Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	463000
CY2022Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	807000
CY2023Q4	us-gaap	Assets Assets	612880000
CY2022Q4	us-gaap	Assets Assets	497236000
CY2023Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	9961000
CY2022Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	4350000
CY2023Q4	sndx	Collaboration Payable Current CollaborationPayableCurrent	7232000
CY2022Q4	sndx	Collaboration Payable Current CollaborationPayableCurrent	0
CY2023Q4	us-gaap	Accrued Liabilities And Other Liabilities AccruedLiabilitiesAndOtherLiabilities	39856000
CY2022Q4	us-gaap	Accrued Liabilities And Other Liabilities AccruedLiabilitiesAndOtherLiabilities	24276000
CY2023Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	1035000
CY2022Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	434000
CY2023Q4	sndx	Current Portion Of Capital Lease CurrentPortionOfCapitalLease	12000
CY2022Q4	sndx	Current Portion Of Capital Lease CurrentPortionOfCapitalLease	5000
CY2023Q4	us-gaap	Liabilities Current LiabilitiesCurrent	58096000
CY2022Q4	us-gaap	Liabilities Current LiabilitiesCurrent	29065000
CY2023Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	578000
CY2022Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	709000
CY2023Q4	sndx	Capital Lease Less Current Portion CapitalLeaseLessCurrentPortion	10000
CY2022Q4	sndx	Capital Lease Less Current Portion CapitalLeaseLessCurrentPortion	13000
CY2023Q4	us-gaap	Liabilities Noncurrent LiabilitiesNoncurrent	588000
CY2022Q4	us-gaap	Liabilities Noncurrent LiabilitiesNoncurrent	722000
CY2023Q4	us-gaap	Liabilities Liabilities	58684000
CY2022Q4	us-gaap	Liabilities Liabilities	29787000
CY2023Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.001
CY2022Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.001
CY2023Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	10000000
CY2022Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	10000000
CY2023Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0
CY2022Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0
CY2023Q4	us-gaap	Preferred Stock Value PreferredStockValue	0
CY2022Q4	us-gaap	Preferred Stock Value PreferredStockValue	0
CY2023Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.0001
CY2022Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.0001
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	200000000
CY2022Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000
CY2023Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	84826632
CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	68111385
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	8000
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	7000
CY2023Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	1456370000
CY2022Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	1161288000
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	218000
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-806000
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-902400000
CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-693040000
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	554196000
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	467449000
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	612880000
CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	497236000
CY2023	us-gaap	Proceeds From License Fees Received ProceedsFromLicenseFeesReceived	0
CY2022	us-gaap	Proceeds From License Fees Received ProceedsFromLicenseFeesReceived	0
CY2021	us-gaap	Proceeds From License Fees Received ProceedsFromLicenseFeesReceived	139709000
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	0
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	0
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	139709000
CY2023	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	163032000
CY2022	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	118499000
CY2021	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	88248000
CY2023	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	66922000
CY2022	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	33258000
CY2021	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	25241000
CY2023	us-gaap	Operating Expenses OperatingExpenses	229954000
CY2022	us-gaap	Operating Expenses OperatingExpenses	151757000
CY2021	us-gaap	Operating Expenses OperatingExpenses	113489000
CY2023	us-gaap	Operating Income Loss OperatingIncomeLoss	-229954000
CY2022	us-gaap	Operating Income Loss OperatingIncomeLoss	-151757000
CY2021	us-gaap	Operating Income Loss OperatingIncomeLoss	26220000
CY2023	us-gaap	Interest Expense InterestExpense	208000
CY2022	us-gaap	Interest Expense InterestExpense	3137000
CY2021	us-gaap	Interest Expense InterestExpense	1899000
CY2023	us-gaap	Investment Income Interest InvestmentIncomeInterest	21163000
CY2022	us-gaap	Investment Income Interest InvestmentIncomeInterest	5872000
CY2021	us-gaap	Investment Income Interest InvestmentIncomeInterest	403000
CY2023	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-361000
CY2022	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-316000
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	202000
CY2023	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	20594000
CY2022	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	2419000
CY2021	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-1294000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-209360000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-149338000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	24926000
CY2023	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-209360000
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-149338000
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	24926000
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-2.98
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-2.46
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.48
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-2.98
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-2.46
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.46
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70370519
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	60760906
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	52064809
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70370519
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	60760906
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	53622904
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-209360000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-149338000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	24926000
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	1024000
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-851000
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	49000
CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-208336000
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-150189000
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-24975000
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	252188000
CY2021	sndx	Stock Issued During Period Value At The Market Offering Expenses StockIssuedDuringPeriodValueAtTheMarketOfferingExpenses	159000
CY2021	sndx	Stock Issued During Period Value At The Market Offering Net StockIssuedDuringPeriodValueAtTheMarketOfferingNet	5131000
CY2021	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	24848000
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	13317000
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	49000
CY2021	sndx	Employee Withholdings Espp EmployeeWithholdingsEspp	367000
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	6336000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	24926000
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	408368000
CY2022	sndx	Stock Issued During Period Value At The Market Offering Net StockIssuedDuringPeriodValueAtTheMarketOfferingNet	19425000
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	16019000
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-851000
CY2022	sndx	Employee Withholdings Espp EmployeeWithholdingsEspp	401000
CY2022	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	11459000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-149338000
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	467449000
CY2023	sndx	Stock Issued During Period Value At The Market Offering Net StockIssuedDuringPeriodValueAtTheMarketOfferingNet	42139000
CY2023	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	30951000
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	1024000
CY2023	sndx	Employee Withholdings Espp EmployeeWithholdingsEspp	910000
CY2023	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	5128000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-209360000
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	554196000
CY2023	us-gaap	Profit Loss ProfitLoss	-209360000
CY2022	us-gaap	Profit Loss ProfitLoss	-149338000
CY2021	us-gaap	Profit Loss ProfitLoss	24926000
CY2023	sndx	Depreciation And Related Adjustment DepreciationAndRelatedAdjustment	12000
CY2022	sndx	Depreciation And Related Adjustment DepreciationAndRelatedAdjustment	33000
CY2021	sndx	Depreciation And Related Adjustment DepreciationAndRelatedAdjustment	43000
CY2023	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	14803000
CY2022	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	3382000
CY2021	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-644000
CY2023	sndx	Noncash Operating Lease Expense NoncashOperatingLeaseExpense	739000
CY2022	sndx	Noncash Operating Lease Expense NoncashOperatingLeaseExpense	421000
CY2021	sndx	Noncash Operating Lease Expense NoncashOperatingLeaseExpense	413000
CY2023	sndx	Paid In Kind Interest And Interest Reversal PaidInKindInterestAndInterestReversal	0
CY2022	sndx	Paid In Kind Interest And Interest Reversal PaidInKindInterestAndInterestReversal	1103000
CY2021	sndx	Paid In Kind Interest And Interest Reversal PaidInKindInterestAndInterestReversal	-225000
CY2023	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	0
CY2022	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	187000
CY2021	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	389000
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	30951000
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	16019000
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	13317000
CY2023	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	0
CY2022	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	0
CY2021	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	1000
CY2023	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-676000
CY2022	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	2972000
CY2021	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	1394000
CY2023	sndx	Increase Decrease In Collaboration Receivable IncreaseDecreaseInCollaborationReceivable	10706000
CY2022	sndx	Increase Decrease In Collaboration Receivable IncreaseDecreaseInCollaborationReceivable	-3474000
CY2021	sndx	Increase Decrease In Collaboration Receivable IncreaseDecreaseInCollaborationReceivable	0
CY2023	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	5611000
CY2022	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-1319000
CY2021	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	2161000
CY2023	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	0
CY2022	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	0
CY2021	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	-13133000
CY2023	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	14867000
CY2022	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	9421000
CY2021	us-gaap	Increase Decrease In Accrued Liabilities And Other Operating Liabilities IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities	2769000
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-160601000
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-133675000
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	29131000
CY2023	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	0
CY2022	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	0
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	129000
CY2023	us-gaap	Proceeds From Sale Of Machinery And Equipment ProceedsFromSaleOfMachineryAndEquipment	0
CY2022	us-gaap	Proceeds From Sale Of Machinery And Equipment ProceedsFromSaleOfMachineryAndEquipment	225000
CY2021	us-gaap	Proceeds From Sale Of Machinery And Equipment ProceedsFromSaleOfMachineryAndEquipment	0
CY2023	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	354606000
CY2022	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	495346000
CY2021	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	294719000
CY2023	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	472215000
CY2022	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	308933000
CY2021	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	253975000
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	117609000
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-186188000
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-40873000
CY2023	us-gaap	Payments For Proceeds From Deposit On Loan PaymentsForProceedsFromDepositOnLoan	0
CY2022	us-gaap	Payments For Proceeds From Deposit On Loan PaymentsForProceedsFromDepositOnLoan	20996000
CY2021	us-gaap	Payments For Proceeds From Deposit On Loan PaymentsForProceedsFromDepositOnLoan	0
CY2023	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	910000
CY2022	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	401000
CY2021	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	367000
CY2023	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	5128000
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	11459000
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	6336000
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	264132000
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	172254000
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	118464000
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	221140000
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-147609000
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	106722000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	74471000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	222080000
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	115358000
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	295611000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	74471000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	222080000
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	295394000
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	74356000
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	221965000
CY2023Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	217000
CY2022Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	115000
CY2021Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	115000
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	295611000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	74471000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	222080000
CY2023	us-gaap	Nature Of Operations NatureOfOperations	<p style="font-size:10pt;margin-top:12pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">1. Nature of Business</span><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">Syndax Pharmaceuticals, Inc. (“the Company” or “Syndax”) is a clinical-stage biopharmaceutical company developing an innovative pipeline of cancer therapies. The Company's two lead product candidates are revumenib and axatilimab. The Company is developing revumenib, a potent, selective, small molecule inhibitor of the menin-MLL binding interaction for the treatment of KMT2A rearranged, (“KMT2Ar”), also known as mixed lineage leukemia rearranged, (“MLLr”), acute leukemias including acute lymphoblastic leukemia, (“ALL”), and acute myeloid leukemia, or AML, and nucleophosmin 1, also known as NPM1, mutant AML. The Company is also exploring the use of revumenib as a treatment in solid tumors, specifically its activity in metastatic colorectal cancer. The Company is developing axatilimab, a monoclonal antibody that blocks the colony stimulating factor 1 receptor, (“CSF-1R”), in chronic graft-versus-host disease, (“cGVHD”), as well as idiopathic pulmonary fibrosis, (“IPF”). The Company plans to continue to leverage the technical and business expertise of its management team and scientific collaborators to license, acquire and develop additional therapeutics to expand its pipeline.</span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:12pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">Since its inception, the Company has devoted its efforts principally to research and development and raising capital. The Company is subject to risks common to companies in the development stage, including, but not limited to, successful development of therapeutics, obtaining additional funding, protection of proprietary therapeutics, compliance with government regulations, fluctuations in operating results, dependence on key personnel and collaborative partners, and risks associated with industry changes. The Company’s long-term success is dependent upon its ability to successfully develop and market its product candidates, expand its oncology drug pipeline, earn revenue, obtain additional capital when needed, and ultimately, achieve profitable operations. The Company anticipates that it will be several years before any of its product candidates is approved, if ever, and the Company begins to generate revenue from sales of such product candidates. Accordingly, management expects to incur substantial losses on the ongoing development of its product candidates and does not expect to achieve positive cash flow from operations for the foreseeable future, if ever. As a result, the Company will continue to require additional capital to move forward with its business plan. While certain amounts of this additional capital were raised in the past, there can be no assurance that funds necessary beyond these amounts will be available in amounts or on terms sufficient to ensure ongoing operations.</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:12pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">The Company’s management believes that the cash, cash equivalents and short-term investments balances as of December 31, 2023, should enable the Company to maintain its planned operations for at least 12 months from the issuance date of these financial statements. The Company’s ability to fund all of its planned operations internally beyond that date, including the completion of its ongoing and planned clinical trial activities, may be substantially dependent upon whether the Company can obtain sufficient funding on terms acceptable to the Company. Proceeds from additional capital transactions would allow the Company to accelerate and/or expand its planned research and development activities. In the event that sufficient funds were not available, the Company may be required to delay or reduce expenditures to conserve cash, which could involve scaling back or curtailing development and selling, general and administrative activities.</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:12pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">The Company is subject to challenges and risks specific to its business and ability to execute on the strategy, as well as risks and uncertainties common to companies in the pharmaceutical industry with development and commercial operations, including, without limitation, risks and uncertainties associated with: obtaining regulatory approval of the Company’s late-stage product candidate; delays or problems in the supply of the Company’s products, loss of single source suppliers or failure to comply with manufacturing regulations; identifying, acquiring or in-licensing additional products or product candidates; pharmaceutical product development and the inherent uncertainty of clinical success; and the challenges of protecting and enhancing the Company’s intellectual property rights; complying with applicable regulatory requirements.</span></p>
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<p style="margin-left:4.533%;font-size:10pt;margin-top:12pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;">Estimates</span><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of costs and expenses during the reporting period. The Company bases estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The Company’s actual results may differ from these estimates under different assumptions or conditions.</span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">Estimates and assumptions about future events and their effects cannot be determined with certainty and therefore require the exercise of judgment. As of the date of issuance of these financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. These estimates may change as new events occur and additional information is obtained and are recognized in the consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to the Company’s consolidated financial statements.</span></p>
CY2023	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	1
CY2023	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<p style="margin-left:4.533%;font-size:10pt;margin-top:12pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;">Concentrations of Credit Risk</span><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">Cash and cash equivalents, restricted cash, and short and long-term investments are financial instruments that potentially subject the Company to concentrations of credit risk. Substantially all of the Company’s cash, cash equivalents, and short and long-term investments were deposited in accounts at two financial institutions, and at times, such deposits may exceed federally insured limits. The Company has not experienced any losses in such accounts, and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company’s available-for-sale investments primarily consist of government money market funds, corporate debt securities, commercial paper, credit card asset-backed securities and overnight deposits and potentially subject the Company to concentrations of credit risk.</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p>
CY2023	us-gaap	Tangible Asset Impairment Charges TangibleAssetImpairmentCharges	0
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	1500000
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	1600000
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.14
CY2023	us-gaap	Operating Lease Expense OperatingLeaseExpense	743000
CY2023	us-gaap	Guarantees Indemnifications And Warranties Policies GuaranteesIndemnificationsAndWarrantiesPolicies	<p style="margin-left:4.533%;font-size:10pt;margin-top:12pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;">Guarantees and Indemnifications</span><span style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;"> </span></p><p style="text-indent:4.533%;font-size:10pt;margin-top:6pt;font-family:Times New Roman;margin-bottom:0;text-align:left;"><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">As permitted under Delaware law, the Company indemnifies its officers, directors, and employees for certain events or occurrences that happen by reason of the relationship with, or position held at, the Company. The Company has standard indemnification arrangements under office leases (as described in Note 5, </span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;font-style:italic;min-width:fit-content;">Leases</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> to these consolidated financial statements) that require it to indemnify the landlord against all costs, expenses, fines, suits, claims, demands, liabilities, and actions directly resulting from any breach, violation, or nonperformance of any covenant or condition of the Company’s lease. Through December 31, 2023</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;">, the Company had not experienced any losses related to these indemnification obligations and </span><span style="font-size:10pt;font-family:Times New Roman;color:#000000;white-space:pre-wrap;min-width:fit-content;">no</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> claims were outstanding. The Company does not expect significant claims related to these indemnification obligations, and consequently, concluded that the fair value of these obligations is negligible, and </span><span style="font-size:10pt;font-family:Times New Roman;color:#000000;white-space:pre-wrap;min-width:fit-content;">no</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> related reserves were established.</span><span style="color:#000000;white-space:pre-wrap;font-size:10pt;font-family:Times New Roman;min-width:fit-content;"> </span></p>
CY2023	us-gaap	Operating Lease Payments OperatingLeasePayments	924000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	1196000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	606000
CY2023Q4	sndx	Lessee Operating Lease Liability Payments Due After Year Two LesseeOperatingLeaseLiabilityPaymentsDueAfterYearTwo	0
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	1802000
CY2023Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	189000
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	1613000
CY2023Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	25864000
CY2022Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	22441000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-209360000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-149338000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	24926000
CY2023	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-209360000
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-149338000
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	24926000
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70371000
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	60761000
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	52065000
CY2021	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1558000
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70371000
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	60761000
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	53623000
CY2023Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	419000
CY2022Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	419000
CY2023Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	411000
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	399000
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	8000
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	20000
CY2023	us-gaap	Depreciation Depreciation	12000000
CY2022	us-gaap	Depreciation Depreciation	33000000
CY2023	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	0
CY2023Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	304916000
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	257000
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	40000
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	305133000
CY2022Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	422581000
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	806000
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	421775000
CY2023Q4	us-gaap	Prepaid Insurance PrepaidInsurance	807000
CY2022Q4	us-gaap	Prepaid Insurance PrepaidInsurance	692000
CY2023Q4	us-gaap	Interest Receivable Current InterestReceivableCurrent	1227000
CY2022Q4	us-gaap	Interest Receivable Current InterestReceivableCurrent	583000
CY2023Q4	sndx	Prepaid Subscriptions PrepaidSubscriptions	769000
CY2022Q4	sndx	Prepaid Subscriptions PrepaidSubscriptions	446000
CY2023Q4	sndx	Prepaid State And Local Taxes PrepaidStateAndLocalTaxes	264000
CY2022Q4	sndx	Prepaid State And Local Taxes PrepaidStateAndLocalTaxes	3000
CY2023Q4	us-gaap	Prepaid Rent PrepaidRent	163000
CY2022Q4	us-gaap	Prepaid Rent PrepaidRent	74000
CY2023Q4	us-gaap	Other Prepaid Expense Current OtherPrepaidExpenseCurrent	63000
CY2022Q4	us-gaap	Other Prepaid Expense Current OtherPrepaidExpenseCurrent	117000
CY2023Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	3293000
CY2022Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	1915000
CY2023Q4	sndx	Accrued Clinical Costs Current AccruedClinicalCostsCurrent	16346000
CY2022Q4	sndx	Accrued Clinical Costs Current AccruedClinicalCostsCurrent	14375000
CY2023Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	11172000
CY2022Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	5945000
CY2023Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	1450000
CY2022Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	1352000
CY2023Q4	sndx	Accrued Milestone Costs AccruedMilestoneCosts	10000000
CY2022Q4	sndx	Accrued Milestone Costs AccruedMilestoneCosts	2000000
CY2023Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	888000
CY2022Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	604000
CY2023Q4	us-gaap	Accrued Liabilities And Other Liabilities AccruedLiabilitiesAndOtherLiabilities	39856000
CY2022Q4	us-gaap	Accrued Liabilities And Other Liabilities AccruedLiabilitiesAndOtherLiabilities	24276000
CY2021Q4	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	3802144
CY2021Q4	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	81200000
CY2023Q1	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	86000
CY2023Q1	sndx	Number Of Pre Funded Warrants Exercised For Common Stock NumberOfPreFundedWarrantsExercisedForCommonStock	85998
CY2023Q2	sndx	Number Of Pre Funded Warrants Exercised For Common Stock NumberOfPreFundedWarrantsExercisedForCommonStock	272996
CY2023Q2	sndx	Number Of Pre Funded Warrants Exercised For Common Stock NumberOfPreFundedWarrantsExercisedForCommonStock	498137
CY2022Q4	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	7840909
CY2022Q4	sndx	Offering Price Per Share OfferingPricePerShare	22
CY2022Q4	sndx	Gross Proceeds From Offering GrossProceedsFromOffering	172500000
CY2023Q4	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	12432431
CY2023Q4	sndx	Offering Price Per Share OfferingPricePerShare	18.5
CY2023Q4	sndx	Gross Proceeds From Offering GrossProceedsFromOffering	230000000
CY2023Q4	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	23906260
CY2023	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	30951000
CY2022	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	16019000
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	13317000
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y10D
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y14D
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y7D
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.7513
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.7787
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.8584
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0365
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0252
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0067
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	7981677
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	14.42
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P7Y3M18D
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	88016000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	3800691
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	23.75
CY2023	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	662042
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	8.08
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod	435468
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice	23.14
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	10684858
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	17.78
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P7Y3M18D
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	5004000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	2795000
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	55091000
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	5468638
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	14.32
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P5Y8M12D
CY2023Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	43160000
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber	10684858
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice	17.78
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1	P7Y3M18D
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue	55091000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	16.2
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	12.64
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	14.7
CY2023	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	662042
CY2023	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	5100000
CY2022	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	1300000
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	11500000
CY2021	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	842424
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	6300000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	9500000
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	17000000
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	10100000
CY2023	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	1300000
CY2022	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	712000
CY2021	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	444000
CY2022	sndx	Prepayment Fee PrepaymentFee	400000
CY2022Q4	sndx	Deferred Tax Assets Capitalized Research And Development Costs DeferredTaxAssetsCapitalizedResearchAndDevelopmentCosts	48917000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	10276000
CY2023	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2022	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2023	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.132
CY2022	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.025
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.029
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	-0.015
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	-0.01
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.05
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	-0.01
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	-0.002
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	-0.005
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.349
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.241
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.192
CY2023	sndx	Return To Provision True Up ReturnToProvisionTrueUp	0
CY2022	sndx	Return To Provision True Up ReturnToProvisionTrueUp	-0.002
CY2021	sndx	Return To Provision True Up ReturnToProvisionTrueUp	0
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.008
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	-0.002
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	32664000
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	23650000
CY2023Q4	us-gaap	Deferred Tax Assets In Process Research And Development DeferredTaxAssetsInProcessResearchAndDevelopment	11765000
CY2022Q4	us-gaap	Deferred Tax Assets In Process Research And Development DeferredTaxAssetsInProcessResearchAndDevelopment	8124000
CY2023Q4	sndx	Deferred Tax Assets Capitalized Start Up And Other Costs DeferredTaxAssetsCapitalizedStartUpAndOtherCosts	68859000
CY2022Q4	sndx	Deferred Tax Assets Capitalized Start Up And Other Costs DeferredTaxAssetsCapitalizedStartUpAndOtherCosts	45374000
CY2023Q4	sndx	Deferred Tax Assets Capitalized Research And Development Costs DeferredTaxAssetsCapitalizedResearchAndDevelopmentCosts	79562000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	1985000
CY2023Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	36000
CY2022Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	27000
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	205957000
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	133081000
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	205957000
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	133081000
CY2023Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	0
CY2022Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	0
CY2023	us-gaap	Valuation Allowance Methodologies And Assumptions ValuationAllowanceMethodologiesAndAssumptions	The Company has provided a valuation allowance for the full amount of the net deferred tax assets as the realization of the deferred tax assets is not determined to be more likely than not. The valuation allowance increased by $72.9 million in 2023 due to the increase in deferred tax assets, primarily driven by the generation of net operating losses and capitalized research expenses, and capitalized start-up costs. The valuation allowance increased by $35.9 million in 2022 due to the increase in deferred tax assets, primarily driven by the generation of net operating losses and capitalized start-up costs, partially offset by a decrease to other deferred tax assets.
CY2023	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	72900000
CY2022	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	35900000
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	136400000
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	63500000
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	79600000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense DeferredTaxAssetsTaxDeferredExpense	53700000
CY2023	us-gaap	Unrecognized Tax Benefits Period Increase Decrease UnrecognizedTaxBenefitsPeriodIncreaseDecrease	100000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	143000
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	163000
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	163000
CY2023	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	20000
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	143000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	143000
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	163000
CY2023Q4	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	0
CY2022Q4	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	0
CY2023	us-gaap	Interest Paid Net InterestPaidNet	0
CY2022	us-gaap	Interest Paid Net InterestPaidNet	2059000
CY2021	us-gaap	Interest Paid Net InterestPaidNet	1997000
CY2023	us-gaap	Debt Issuance Costs Incurred During Noncash Or Partial Noncash Transaction DebtIssuanceCostsIncurredDuringNoncashOrPartialNoncashTransaction	250000
CY2022	us-gaap	Debt Issuance Costs Incurred During Noncash Or Partial Noncash Transaction DebtIssuanceCostsIncurredDuringNoncashOrPartialNoncashTransaction	131000
CY2021	us-gaap	Debt Issuance Costs Incurred During Noncash Or Partial Noncash Transaction DebtIssuanceCostsIncurredDuringNoncashOrPartialNoncashTransaction	134000

Files In Submission

Name	View Source	Status
0000950170-24-021253-index-headers.html	Edgar Link	pending
0000950170-24-021253-index.html	Edgar Link	pending
0000950170-24-021253.txt	Edgar Link	pending
0000950170-24-021253-xbrl.zip	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
img207175068_0.jpg	Edgar Link	pending
img207175068_1.jpg	Edgar Link	pending
img207175068_2.jpg	Edgar Link	pending
img207175068_3.jpg	Edgar Link	pending
img207175068_4.jpg	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending
sndx-20231231.htm	Edgar Link	pending
sndx-20231231.xsd	Edgar Link	pending
sndx-ex10_16.htm	Edgar Link	pending
sndx-ex10_20.htm	Edgar Link	pending
sndx-ex10_22.htm	Edgar Link	pending
sndx-ex10_23.htm	Edgar Link	pending
sndx-ex10_25.htm	Edgar Link	pending
sndx-ex10_27.htm	Edgar Link	pending
sndx-ex10_30.htm	Edgar Link	pending
sndx-ex10_31.htm	Edgar Link	pending
sndx-ex23_1.htm	Edgar Link	pending
sndx-ex31_1.htm	Edgar Link	pending
sndx-ex31_2.htm	Edgar Link	pending
sndx-ex32_1.htm	Edgar Link	pending
sndx-ex4_3.htm	Edgar Link	pending
sndx-ex97.htm	Edgar Link	pending
sndx-20231231_htm.xml	Edgar Link	completed
FilingSummary.xml	Edgar Link	unprocessable

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$SNDX
Syndax Pharmaceuticals Inc Stock $sndx

2024 Q1 Form 10-K Financial Statement

#000095017024021253 Filed on February 27, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SNDX Syndax Pharmaceuticals Inc Stock $sndx

2024 Q1 Form 10-K Financial Statement

#000095017024021253 Filed on February 27, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SNDX
Syndax Pharmaceuticals Inc Stock $sndx