$SLRN
ACELYRIN, Inc. Stock $slrn

$slrn Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000196291824000032 Filed on March 28, 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	$24.74M	$21.74M	$66.18M
YoY Change	107.69%		388.51%
% of Gross Profit
Research & Development	$58.03M	$83.37M	$355.9M
YoY Change	-65.44%		539.71%
% of Gross Profit
Depreciation & Amortization	$55.00K	$48.00K	$115.0K
YoY Change
% of Gross Profit
Operating Expenses	$82.77M	$105.1M	$422.1M
YoY Change	-53.97%		510.1%
Operating Profit	-$82.77M		-$422.1M
YoY Change	-53.97%		510.1%
Interest Expense	$9.150M	$10.07M	$40.85M
YoY Change	165.53%		799.89%
% of Operating Profit
Other Income/Expense, Net	$38.65M	-$169.0K	-$423.0K
YoY Change	-61450.79%		220.45%
Pretax Income	-$34.97M	-$95.21M	-$381.6M
YoY Change	-80.18%		489.21%
Income Tax			$0.00
% Of Pretax Income
Net Earnings	-$34.97M	-$95.21M	-$381.6M
YoY Change	-80.18%		489.21%
Net Earnings / Revenue
Basic Earnings Per Share	-$0.36		-$5.43
Diluted Earnings Per Share	-$0.36	-$0.97	-$3.88
COMMON SHARES
Basic Shares Outstanding	98.37M shares	97.34M shares	70.25M shares
Diluted Shares Outstanding	97.91M shares		70.25M shares

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments	$678.5M	$721.3M	$721.3M
YoY Change	134.63%		129.27%
Cash & Equivalents	$264.5M	$218.1M	$218.1M
Short-Term Investments	$414.0M	$503.2M	$503.2M
Other Short-Term Assets	$10.09M	$14.55M	$10.56M
YoY Change	318.24%		900.28%
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets	$694.0M	$736.6M	$736.6M
YoY Change	137.78%	133.07%	133.07%
LONG-TERM ASSETS
Property, Plant & Equipment	$2.179M	$3.374M	$3.374M
YoY Change	815.55%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets	$175.0K	$2.678M	$2.678M
YoY Change	-96.56%		-30.6%
Total Long-Term Assets	$3.503M	$6.052M	$6.052M
YoY Change	-47.43%	56.83%	56.83%
TOTAL ASSETS
Total Short-Term Assets	$694.0M	$736.6M	$736.6M
Total Long-Term Assets	$3.503M	$6.052M	$6.052M
Total Assets	$697.5M	$742.7M	$742.7M
YoY Change	133.65%	132.15%	132.15%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$9.994M	$41.92M	$41.92M
YoY Change	-7.21%	604.89%	604.89%
Accrued Expenses	$41.71M	$42.27M	$42.27M
YoY Change	112.66%		324.64%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$52.28M	$85.16M	$85.16M
YoY Change	55.31%	435.56%	435.56%
LONG-TERM LIABILITIES
Long-Term Debt	$0.00	$0.00	$0.00
YoY Change
Other Long-Term Liabilities	$1.134M	$1.194M	$1.194M
YoY Change	-90.24%		-88.4%
Total Long-Term Liabilities	$1.134M	$1.194M	$1.194M
YoY Change	-90.24%		-88.4%
TOTAL LIABILITIES
Total Short-Term Liabilities	$52.28M	$85.16M	$85.16M
Total Long-Term Liabilities	$1.134M	$1.194M	$1.194M
Total Liabilities	$53.42M	$86.35M	$86.35M
YoY Change	17.98%	229.69%	229.69%
SHAREHOLDERS EQUITY
Retained Earnings	-$523.7M	-$488.7M
YoY Change	84.73%	356.4%
Common Stock	$1.000K	$1.000K
YoY Change
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$644.1M	$656.3M	$656.3M
YoY Change
Total Liabilities & Shareholders Equity	$697.5M	$742.7M	$742.7M
YoY Change	133.65%	132.15%	132.15%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	-$34.97M	-$95.21M	-$381.6M
YoY Change	-80.18%		489.21%
Depreciation, Depletion And Amortization	$55.00K	$48.00K	$115.0K
YoY Change
Cash From Operating Activities	-$57.30M	-$73.63M	-$169.7M
YoY Change	126.48%		175.85%
INVESTING ACTIVITIES
Capital Expenditures	$55.00K	$98.00K	$2.294M
YoY Change	-76.89%
Acquisitions
YoY Change
Other Investing Activities	$101.0M	-$92.51M	-$445.5M
YoY Change	-32.87%		830.46%
Cash From Investing Activities	$100.9M	-$92.61M	-$447.7M
YoY Change	112.22%		835.26%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net			$576.8M
YoY Change			118.49%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	$2.807M	2.596M	568.4M
YoY Change	-2275.97%		107.26%
NET CHANGE
Cash From Operating Activities	-$57.30M	-73.63M	-169.7M
Cash From Investing Activities	$100.9M	-92.61M	-447.7M
Cash From Financing Activities	$2.807M	2.596M	568.4M
Net Change In Cash	$46.40M	-163.6M	-49.01M
YoY Change	110.12%		-129.73%
FREE CASH FLOW
Cash From Operating Activities	-$57.30M	-$73.63M	-$169.7M
Capital Expenditures	$55.00K	$98.00K	$2.294M
Free Cash Flow	-$57.36M	-$73.73M	-$172.0M
YoY Change	124.59%		179.58%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2023	us-gaap	Investment Income Interest InvestmentIncomeInterest	30555000	usd
CY2023	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-423000	usd
CY2022	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-132000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-381641000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-86000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	0	usd
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	687398	shares
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-381641000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-64772000	usd
CY2021	slrn	Increase Decrease In Accrued Research And Development Expenses IncreaseDecreaseInAccruedResearchAndDevelopmentExpenses	9697000	usd
CY2022	slrn	Increase Decrease In Accrued Compensation And Other Current Liabilities IncreaseDecreaseInAccruedCompensationAndOtherCurrentLiabilities	3042000	usd
CY2021	slrn	Increase Decrease In Accrued Compensation And Other Current Liabilities IncreaseDecreaseInAccruedCompensationAndOtherCurrentLiabilities	860000	usd
CY2023	us-gaap	Increase Decrease In Operating Lease Liability IncreaseDecreaseInOperatingLeaseLiability	-154000	usd
CY2022	us-gaap	Increase Decrease In Operating Lease Liability IncreaseDecreaseInOperatingLeaseLiability	0	usd
CY2023	slrn	Increase Decrease In Severance Liability IncreaseDecreaseInSeveranceLiability	970000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-41839000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-41839000	usd
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-60.87
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-5000000	usd
CY2023	dei	Entity Central Index Key EntityCentralIndexKey	0001962918
CY2023	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2023
CY2023	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2023	dei	Amendment Flag AmendmentFlag	false
CY2023Q2	us-gaap	Stockholders Equity Note Stock Split Conversion Ratio1 StockholdersEquityNoteStockSplitConversionRatio1	0.5071
CY2023	us-gaap	Fair Value Recurring Basis Unobservable Input Reconciliation Liability Gain Loss Statement Of Income Extensible List FairValueRecurringBasisUnobservableInputReconciliationLiabilityGainLossStatementOfIncomeExtensibleList	http://fasb.org/us-gaap/2023#GainLossOnDerivativeInstrumentsNetPretax
CY2022Q3	us-gaap	Derivative Liability Statement Of Financial Position Extensible Enumeration DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration	http://fasb.org/us-gaap/2023#DerivativeLiabilitiesNoncurrent
CY2022Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss Current Statement Of Financial Position Extensible List DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossCurrentStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2023#PrepaidExpenseAndOtherAssetsCurrent
CY2023Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss Current Statement Of Financial Position Extensible List DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossCurrentStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2023#PrepaidExpenseAndOtherAssetsCurrent
CY2023Q4	us-gaap	Operating Lease Liability Current Statement Of Financial Position Extensible List OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList	http://acelyrin.com/20231231#AccruedCompensationAndOtherCurrentLiabilities
CY2023	dei	Document Annual Report DocumentAnnualReport	true
CY2023	dei	Document Period End Date DocumentPeriodEndDate	2023-12-31
CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	001-04321
CY2023	dei	Entity Registrant Name EntityRegistrantName	ACELYRIN, INC.
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	85-2406735
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	4149 Liberty Canyon Road
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	Agoura Hills
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	CA
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	91301
CY2023	dei	City Area Code CityAreaCode	805
CY2023	dei	Local Phone Number LocalPhoneNumber	730-0360
CY2023	dei	Security12b Title Security12bTitle	Common Stock, par value $0.0001 per share
CY2023	dei	Trading Symbol TradingSymbol	SLRN
CY2023	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2023	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	No
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	Non-accelerated Filer
CY2023	dei	Entity Small Business EntitySmallBusiness	false
CY2023	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	true
CY2023	dei	Entity Ex Transition Period EntityExTransitionPeriod	false
CY2023	dei	Document Fin Stmt Error Correction Flag DocumentFinStmtErrorCorrectionFlag	false
CY2023	dei	Entity Shell Company EntityShellCompany	false
CY2023Q2	dei	Entity Public Float EntityPublicFloat	1458200000	usd
CY2024Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	98365050	shares
CY2023	dei	Auditor Firm AuditorFirmId	238
CY2023	dei	Auditor Name AuditorName	PricewaterhouseCoopers LLP
CY2023	dei	Auditor Location AuditorLocation	San Diego, California
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	218097000	usd
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	267110000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Current DebtSecuritiesAvailableForSaleExcludingAccruedInterestCurrent	503229000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Current DebtSecuritiesAvailableForSaleExcludingAccruedInterestCurrent	47510000	usd
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CY2022Q4	us-gaap	Assets Current AssetsCurrent	316064000	usd
CY2023Q4	us-gaap	Prepaid Expense And Other Assets Noncurrent PrepaidExpenseAndOtherAssetsNoncurrent	2678000	usd
CY2022Q4	us-gaap	Prepaid Expense And Other Assets Noncurrent PrepaidExpenseAndOtherAssetsNoncurrent	3859000	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	1195000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	0	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	2179000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	0	usd
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CY2022Q4	us-gaap	Assets Assets	319923000	usd
CY2023Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	41920000	usd
CY2022Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	5947000	usd
CY2023Q4	slrn	Accrued Research And Development Expense Current AccruedResearchAndDevelopmentExpenseCurrent	35436000	usd
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CY2023Q4	slrn	Accrued Compensation And Other Current Liabilities AccruedCompensationAndOtherCurrentLiabilities	6833000	usd
CY2022Q4	slrn	Accrued Compensation And Other Current Liabilities AccruedCompensationAndOtherCurrentLiabilities	4237000	usd
CY2023Q4	slrn	Severance Liability Current SeveranceLiabilityCurrent	970000	usd
CY2022Q4	slrn	Severance Liability Current SeveranceLiabilityCurrent	0	usd
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CY2022Q4	us-gaap	Liabilities Current LiabilitiesCurrent	15901000	usd
CY2023Q4	us-gaap	Derivative Liabilities Noncurrent DerivativeLiabilitiesNoncurrent	0	usd
CY2022Q4	us-gaap	Derivative Liabilities Noncurrent DerivativeLiabilitiesNoncurrent	10291000	usd
CY2023Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	1194000	usd
CY2022Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	0	usd
CY2023Q4	us-gaap	Liabilities Liabilities	86353000	usd
CY2022Q4	us-gaap	Liabilities Liabilities	26192000	usd
CY2023Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
CY2022Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
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CY2023Q4	us-gaap	Temporary Equity Shares Authorized TemporaryEquitySharesAuthorized	0	shares
CY2023Q4	us-gaap	Temporary Equity Shares Issued TemporaryEquitySharesIssued	0	shares
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CY2022Q4	us-gaap	Temporary Equity Liquidation Preference TemporaryEquityLiquidationPreference	408000000	usd
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CY2022Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
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CY2023Q4	us-gaap	Preferred Stock Value Outstanding PreferredStockValueOutstanding		usd
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CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	2767359	shares
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	1000	usd
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CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	162000	usd
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CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-381393000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-64858000	usd
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CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70249580	shares
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CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	687398	shares
CY2020Q4	us-gaap	Temporary Equity Shares Outstanding TemporaryEquitySharesOutstanding	4056795	shares
CY2020Q4	us-gaap	Temporary Equity Carrying Amount Attributable To Parent TemporaryEquityCarryingAmountAttributableToParent	7916000	usd
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	-466000	usd
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	233000	usd
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	16000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-41839000	usd
CY2021Q4	us-gaap	Temporary Equity Shares Outstanding TemporaryEquitySharesOutstanding	16285718	shares
CY2021Q4	us-gaap	Temporary Equity Carrying Amount Attributable To Parent TemporaryEquityCarryingAmountAttributableToParent	132620000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	-42056000	usd
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	4052000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-64772000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-86000	usd
CY2022Q4	us-gaap	Temporary Equity Shares Outstanding TemporaryEquitySharesOutstanding	40743522	shares
CY2022Q4	us-gaap	Temporary Equity Carrying Amount Attributable To Parent TemporaryEquityCarryingAmountAttributableToParent	396593000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	-102862000	usd
CY2023	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	128735000	usd
CY2023	us-gaap	Adjustments To Additional Paid In Capital Stock Issued Issuance Costs AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	47354000	usd
CY2023	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	573644000	usd
CY2023	slrn	Temporary Equity Shares Conversion Of Convertible Securities TemporaryEquitySharesConversionOfConvertibleSecurities	40743522	shares
CY2023	slrn	Temporary Equity Value Conversion Of Convertible Securities TemporaryEquityValueConversionOfConvertibleSecurities	396593000	usd
CY2023	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	396593000	usd
CY2023	slrn	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures And Tax Withholding Obligation StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeituresAndTaxWithholdingObligation	8325000	usd
CY2023	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	47318000	usd
CY2023	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	149000	usd
CY2023	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2478000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	248000	usd
CY2023Q4	us-gaap	Temporary Equity Shares Outstanding TemporaryEquitySharesOutstanding	0	shares
CY2023Q4	us-gaap	Temporary Equity Carrying Amount Attributable To Parent TemporaryEquityCarryingAmountAttributableToParent	0	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	656337000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-381641000	usd
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	47318000	usd
CY2023	us-gaap	Research And Development Asset Acquired Other Than Through Business Combination Written Off ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff	133057000	usd
CY2022	us-gaap	Research And Development Asset Acquired Other Than Through Business Combination Written Off ResearchAndDevelopmentAssetAcquiredOtherThanThroughBusinessCombinationWrittenOff	0	usd
CY2023	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	10495000	usd
CY2021	us-gaap	Gain Loss On Derivative Instruments Net Pretax GainLossOnDerivativeInstrumentsNetPretax	0	usd
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	0	usd
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	0	usd
CY2022	slrn	Increase Decrease In Prepaid Expense And Other Assets Current IncreaseDecreaseInPrepaidExpenseAndOtherAssetsCurrent	941000	usd
CY2021	us-gaap	Operating Lease Right Of Use Asset Amortization Expense OperatingLeaseRightOfUseAssetAmortizationExpense	0	usd
CY2023	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	34443000	usd
CY2022	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	3776000	usd
CY2021	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	1119000	usd
CY2023	slrn	Increase Decrease In Accrued Research And Development Expenses IncreaseDecreaseInAccruedResearchAndDevelopmentExpenses	24914000	usd
CY2022	slrn	Increase Decrease In Accrued Research And Development Expenses IncreaseDecreaseInAccruedResearchAndDevelopmentExpenses	-3980000	usd
CY2023	slrn	Increase Decrease In Accrued Compensation And Other Current Liabilities IncreaseDecreaseInAccruedCompensationAndOtherCurrentLiabilities	1691000	usd
CY2021	us-gaap	Increase Decrease In Operating Lease Liability IncreaseDecreaseInOperatingLeaseLiability	0	usd
CY2022	slrn	Increase Decrease In Severance Liability IncreaseDecreaseInSeveranceLiability	0	usd
CY2021	slrn	Increase Decrease In Severance Liability IncreaseDecreaseInSeveranceLiability	0	usd
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-169705000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-61520000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-4979000	usd
CY2021	slrn	Increase Decrease In Prepaid Expense And Other Assets Current IncreaseDecreaseInPrepaidExpenseAndOtherAssetsCurrent	49000	usd
CY2023	slrn	Increase Decrease In Prepaid Expenses And Other Assets Noncurrent IncreaseDecreaseInPrepaidExpensesAndOtherAssetsNoncurrent	-1528000	usd
CY2022	slrn	Increase Decrease In Prepaid Expenses And Other Assets Noncurrent IncreaseDecreaseInPrepaidExpensesAndOtherAssetsNoncurrent	1964000	usd
CY2021	slrn	Increase Decrease In Prepaid Expenses And Other Assets Noncurrent IncreaseDecreaseInPrepaidExpensesAndOtherAssetsNoncurrent	0	usd
CY2023	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	10007000	usd
CY2022	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	usd
CY2021	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	usd
CY2023	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	10000000	usd
CY2022	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	0	usd
CY2021	us-gaap	Payments To Acquire Intangible Assets PaymentsToAcquireIntangibleAssets	25000000	usd
CY2023	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	956512000	usd
CY2022	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	175970000	usd
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	0	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	373359000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	128179000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	0	usd
CY2023	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	137696000	usd
CY2022	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	usd
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	0	usd
CY2023	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	2294000	usd
CY2022	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	0	usd
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	0	usd
CY2023	us-gaap	Other Payments To Acquire Businesses OtherPaymentsToAcquireBusinesses	0	usd
CY2022	us-gaap	Other Payments To Acquire Businesses OtherPaymentsToAcquireBusinesses	83000	usd
CY2021	us-gaap	Other Payments To Acquire Businesses OtherPaymentsToAcquireBusinesses	0	usd
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-447744000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-47874000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-25000000	usd
CY2023	us-gaap	Proceeds From Issuance Initial Public Offering ProceedsFromIssuanceInitialPublicOffering	574134000	usd
CY2022	us-gaap	Proceeds From Issuance Initial Public Offering ProceedsFromIssuanceInitialPublicOffering	0	usd
CY2021	us-gaap	Proceeds From Issuance Initial Public Offering ProceedsFromIssuanceInitialPublicOffering	0	usd
CY2023	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2627000	usd
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	0	usd
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	16000	usd
CY2023	us-gaap	Proceeds From Issuance Of Redeemable Convertible Preferred Stock ProceedsFromIssuanceOfRedeemableConvertiblePreferredStock	0	usd
CY2022	us-gaap	Proceeds From Issuance Of Redeemable Convertible Preferred Stock ProceedsFromIssuanceOfRedeemableConvertiblePreferredStock	263973000	usd
CY2021	us-gaap	Proceeds From Issuance Of Redeemable Convertible Preferred Stock ProceedsFromIssuanceOfRedeemableConvertiblePreferredStock	124704000	usd
CY2023	us-gaap	Proceeds From Derivative Instrument Financing Activities ProceedsFromDerivativeInstrumentFinancingActivities		usd
CY2022	us-gaap	Proceeds From Derivative Instrument Financing Activities ProceedsFromDerivativeInstrumentFinancingActivities	10778000	usd
CY2021	us-gaap	Proceeds From Derivative Instrument Financing Activities ProceedsFromDerivativeInstrumentFinancingActivities	0	usd
CY2023	us-gaap	Payments Of Stock Issuance Costs PaymentsOfStockIssuanceCosts	0	usd
CY2022	us-gaap	Payments Of Stock Issuance Costs PaymentsOfStockIssuanceCosts	489000	usd
CY2021	us-gaap	Payments Of Stock Issuance Costs PaymentsOfStockIssuanceCosts	0	usd
CY2023	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	8325000	usd
CY2022	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	0	usd
CY2021	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	0	usd
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	568436000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	274262000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	124720000	usd
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-49013000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	164868000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	94741000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	267110000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	102242000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	7501000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	218097000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	267110000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	102242000	usd
CY2023	us-gaap	Conversion Of Stock Amount Converted1 ConversionOfStockAmountConverted1	396593000	usd
CY2022	us-gaap	Conversion Of Stock Amount Converted1 ConversionOfStockAmountConverted1	0	usd
CY2021	us-gaap	Conversion Of Stock Amount Converted1 ConversionOfStockAmountConverted1	0	usd
CY2023	us-gaap	Stock Issued1 StockIssued1	128735000	usd
CY2022	us-gaap	Stock Issued1 StockIssued1	0	usd
CY2021	us-gaap	Stock Issued1 StockIssued1	0	usd
CY2023	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	1348000	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	usd
CY2023	slrn	Deferred Offering Costs Incurred But Not Yet Paid DeferredOfferingCostsIncurredButNotYetPaid	0	usd
CY2022	slrn	Deferred Offering Costs Incurred But Not Yet Paid DeferredOfferingCostsIncurredButNotYetPaid	285000	usd
CY2021	slrn	Deferred Offering Costs Incurred But Not Yet Paid DeferredOfferingCostsIncurredButNotYetPaid	0	usd
CY2023	slrn	Acquisition Costs Incurred But Not Yet Paid AcquisitionCostsIncurredButNotYetPaid	0	usd
CY2022	slrn	Acquisition Costs Incurred But Not Yet Paid AcquisitionCostsIncurredButNotYetPaid	1038000	usd
CY2021	slrn	Acquisition Costs Incurred But Not Yet Paid AcquisitionCostsIncurredButNotYetPaid	0	usd
CY2023Q4	slrn	Temporary Equity Convertible Conversion Ratio TemporaryEquityConvertibleConversionRatio	1
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-381600000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-64800000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-41800000	usd
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-488700000	usd
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-169700000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-61500000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents And Short Term Investments CashCashEquivalentsAndShortTermInvestments	721300000	usd
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<div style="margin-top:18pt;padding-left:27pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Use of Estimates</span></div><div style="margin-top:6pt;text-align:justify;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of expenses during the reporting period. On an ongoing basis, the Company evaluates estimates and assumptions, including but not limited to those related to the fair value of its derivative tranche liability, the fair value of its common stock, stock-based compensation expense, accruals for research and development expenses, fair value of in-process research and development assets acquired, valuation of deferred tax assets, and uncertain income tax positions. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those estimates or assumptions.</span></div>
CY2023	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	1	segment
CY2023	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<div style="margin-top:18pt;padding-left:27pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Concentration of Credit Risk </span></div><div style="margin-top:6pt;text-align:justify;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Cash and cash equivalents, and short-term marketable securities are financial instruments that potentially subject the Company to concentrations of credit risk. As of December 31, 2023 and 2022, cash consists of cash deposited with one </span></div><div style="margin-top:6pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">financial institution and account balances exceed federally insured limits. Management believes that the Company is not exposed to significant credit risk due to the financial strength of this institution.</span></div><div style="margin-top:12pt;text-align:justify;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The Company also has investments in money market funds, U.S. Treasury obligations, corporate debt obligations, and federal agency obligations, which can be subject to certain credit risks. The Company mitigates the risks by investing in high-grade instruments, limiting its exposure to any one issuer and monitoring the ongoing creditworthiness of the financial institutions and issuers. The Company has not experienced any losses on its financial instruments.</span></div>
CY2023	us-gaap	Intangible Assets Finite Lived Policy Costs Incurred To Renew Or Extend IntangibleAssetsFiniteLivedPolicyCostsIncurredToRenewOrExtend	<div style="margin-top:18pt;padding-left:27pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Patent Costs </span></div><div style="margin-top:6pt;text-align:justify;text-indent:27pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty of the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the consolidated statements of operations and comprehensive loss.</span></div>
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	0	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss Current DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossCurrent	800000	usd
CY2023Q4	slrn	Asset Acquisition Separately Recognized Transactions Severance Payable Current AssetAcquisitionSeparatelyRecognizedTransactionsSeverancePayableCurrent	300000	usd
CY2023Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	711588000	usd
CY2022Q4	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	285733000	usd
CY2022Q4	us-gaap	Derivative Liabilities Noncurrent DerivativeLiabilitiesNoncurrent	10291000	usd
CY2022Q4	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	10291000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	711588000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	285733000	usd
CY2022Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	10291000	usd
CY2021Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	0	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Issues FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues	0	usd
CY2022	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Issues FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues	10778000	usd
CY2023	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	-10291000	usd
CY2022	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Gain Loss Included In Earnings FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings	-487000	usd
CY2023Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	0	usd
CY2022Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Liability Value FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue	10291000	usd
CY2022Q3	us-gaap	Derivative Liabilities DerivativeLiabilities	10800000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss	711426000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	204000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	42000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	711588000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss	285819000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	86000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	285733000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Accrued Interest After Allowance For Credit Loss Current DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossCurrent	100000	usd
CY2023	us-gaap	Debt Securities Available For Sale Accrued Interest Writeoff DebtSecuritiesAvailableForSaleAccruedInterestWriteoff	0	usd
CY2021	us-gaap	Debt Securities Available For Sale Accrued Interest Writeoff DebtSecuritiesAvailableForSaleAccruedInterestWriteoff	0	usd
CY2022	us-gaap	Debt Securities Available For Sale Accrued Interest Writeoff DebtSecuritiesAvailableForSaleAccruedInterestWriteoff	0	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Term DebtSecuritiesAvailableForSaleTerm	P1Y
CY2023Q4	slrn	Prepaid Research And Development Expenses Current PrepaidResearchAndDevelopmentExpensesCurrent	8184000	usd
CY2022Q4	slrn	Prepaid Research And Development Expenses Current PrepaidResearchAndDevelopmentExpensesCurrent	682000	usd
CY2023Q4	us-gaap	Value Added Tax Receivable Current ValueAddedTaxReceivableCurrent	3985000	usd
CY2022Q4	us-gaap	Value Added Tax Receivable Current ValueAddedTaxReceivableCurrent	0	usd
CY2023Q4	us-gaap	Prepaid Insurance PrepaidInsurance	1712000	usd
CY2022Q4	us-gaap	Prepaid Insurance PrepaidInsurance	86000	usd
CY2023Q4	us-gaap	Interest Receivable Current InterestReceivableCurrent	764000	usd
CY2022Q4	us-gaap	Interest Receivable Current InterestReceivableCurrent	138000	usd
CY2023Q4	slrn	Prepaid Other Services Current PrepaidOtherServicesCurrent	667000	usd
CY2022Q4	slrn	Prepaid Other Services Current PrepaidOtherServicesCurrent	288000	usd
CY2023Q4	slrn	Research And Development Credit Receivable Current ResearchAndDevelopmentCreditReceivableCurrent	0	usd
CY2022Q4	slrn	Research And Development Credit Receivable Current ResearchAndDevelopmentCreditReceivableCurrent	250000	usd
CY2023Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	15312000	usd
CY2022Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	1444000	usd
CY2023Q4	slrn	Prepaid Research And Development Expense Noncurrent PrepaidResearchAndDevelopmentExpenseNoncurrent	2644000	usd
CY2022Q4	slrn	Prepaid Research And Development Expense Noncurrent PrepaidResearchAndDevelopmentExpenseNoncurrent	1964000	usd
CY2023Q4	us-gaap	Deposits Assets Noncurrent DepositsAssetsNoncurrent	34000	usd
CY2022Q4	us-gaap	Deposits Assets Noncurrent DepositsAssetsNoncurrent	0	usd
CY2023Q4	slrn	Asset Acquisition Transaction Costs Noncurrent AssetAcquisitionTransactionCostsNoncurrent	0	usd
CY2022Q4	slrn	Asset Acquisition Transaction Costs Noncurrent AssetAcquisitionTransactionCostsNoncurrent	1121000	usd
CY2023Q4	us-gaap	Deferred Costs DeferredCosts	0	usd
CY2022Q4	us-gaap	Deferred Costs DeferredCosts	774000	usd
CY2023Q4	us-gaap	Prepaid Expense And Other Assets Noncurrent PrepaidExpenseAndOtherAssetsNoncurrent	2678000	usd
CY2022Q4	us-gaap	Prepaid Expense And Other Assets Noncurrent PrepaidExpenseAndOtherAssetsNoncurrent	3859000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	2294000	usd
CY2023Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	115000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	2179000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	0	usd
CY2023Q4	slrn	Accrued Clinical Manufacturing Expenses Current AccruedClinicalManufacturingExpensesCurrent	22232000	usd
CY2022Q4	slrn	Accrued Clinical Manufacturing Expenses Current AccruedClinicalManufacturingExpensesCurrent	1292000	usd
CY2023Q4	slrn	Accrued Clinical Expenses Current AccruedClinicalExpensesCurrent	13204000	usd
CY2022Q4	slrn	Accrued Clinical Expenses Current AccruedClinicalExpensesCurrent	4425000	usd
CY2023Q4	slrn	Accrued Research And Development Expense Current AccruedResearchAndDevelopmentExpenseCurrent	35436000	usd
CY2022Q4	slrn	Accrued Research And Development Expense Current AccruedResearchAndDevelopmentExpenseCurrent	5717000	usd
CY2023Q4	us-gaap	Accrued Salaries Current AccruedSalariesCurrent	5417000	usd
CY2022Q4	us-gaap	Accrued Salaries Current AccruedSalariesCurrent	3068000	usd
CY2023Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	1099000	usd
CY2022Q4	us-gaap	Accrued Professional Fees Current AccruedProfessionalFeesCurrent	808000	usd
CY2023Q4	slrn	Accrued Liabilities And Current Liabilities Other AccruedLiabilitiesAndCurrentLiabilitiesOther	317000	usd
CY2022Q4	slrn	Accrued Liabilities And Current Liabilities Other AccruedLiabilitiesAndCurrentLiabilitiesOther	361000	usd
CY2023Q4	slrn	Accrued Compensation And Other Current Liabilities AccruedCompensationAndOtherCurrentLiabilities	6833000	usd
CY2022Q4	slrn	Accrued Compensation And Other Current Liabilities AccruedCompensationAndOtherCurrentLiabilities	4237000	usd
CY2023Q4	us-gaap	Deferred Offering Costs DeferredOfferingCosts	0	usd
CY2022Q4	us-gaap	Deferred Offering Costs DeferredOfferingCosts	200000	usd
CY2023Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance Sheet Amount UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount	142300000	usd
CY2022Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance Sheet Amount UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount	100000	usd
CY2023Q4	slrn	Unrecorded Unconditional Purchase Obligation Accrued Charges UnrecordedUnconditionalPurchaseObligationAccruedCharges	0	usd
CY2022Q4	slrn	Unrecorded Unconditional Purchase Obligation Accrued Charges UnrecordedUnconditionalPurchaseObligationAccruedCharges	0	usd
CY2023Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On First Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary	67567000	usd
CY2023Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Second Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary	53686000	usd
CY2023Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Third Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary	20985000	usd
CY2023Q4	slrn	Unrecorded Unconditional Purchase Obligation To Be Paid After Year Three UnrecordedUnconditionalPurchaseObligationToBePaidAfterYearThree	106000	usd
CY2023Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance Sheet Amount UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount	142344000	usd
CY2023Q1	slrn	Lessee Operating Lease Square Feet Leased LesseeOperatingLeaseSquareFeetLeased	10012	sqft
CY2023Q1	us-gaap	Lessee Operating Lease Term Of Contract LesseeOperatingLeaseTermOfContract	P65M
CY2023Q1	us-gaap	Lessee Operating Lease Renewal Term LesseeOperatingLeaseRenewalTerm	P3Y
CY2023Q1	slrn	Lessee Operating Lease Monthly Payments LesseeOperatingLeaseMonthlyPayments	30500	usd
CY2023Q1	slrn	Lessee Operating Lease Annual Rent Increase Percent LesseeOperatingLeaseAnnualRentIncreasePercent	0.030
CY2023Q1	slrn	Lessee Operating Lease Rent Abatement Term LesseeOperatingLeaseRentAbatementTerm	P6M
CY2023Q4	us-gaap	Security Deposit SecurityDeposit	34000	usd
CY2023Q1	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	1300000	usd
CY2023Q3	slrn	Lessee Operating Lease Lease Not Yet Commenced Square Feet Leased LesseeOperatingLeaseLeaseNotYetCommencedSquareFeetLeased	22365	sqft
CY2023Q3	us-gaap	Lessee Operating Lease Lease Not Yet Commenced Term Of Contract1 LesseeOperatingLeaseLeaseNotYetCommencedTermOfContract1	P60M
CY2023Q3	us-gaap	Lessee Operating Lease Lease Not Yet Commenced Renewal Term1 LesseeOperatingLeaseLeaseNotYetCommencedRenewalTerm1	P3Y
CY2023Q3	slrn	Lessee Operating Lease Lease Not Yet Commenced Monthly Payments LesseeOperatingLeaseLeaseNotYetCommencedMonthlyPayments	150000	usd
CY2023Q3	slrn	Lessee Operating Lease Lease Not Yet Commenced Annual Rent Increase Percent LesseeOperatingLeaseLeaseNotYetCommencedAnnualRentIncreasePercent	0.035
CY2023	us-gaap	Operating Lease Cost OperatingLeaseCost	300000	usd
CY2023	us-gaap	Short Term Lease Cost ShortTermLeaseCost	100000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	375000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	386000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	398000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	409000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	280000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	1848000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	434000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	1414000	usd
CY2023Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	220000	usd
CY2023Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	1194000	usd
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P56M
CY2023Q4	us-gaap	Lessee Operating Lease Discount Rate LesseeOperatingLeaseDiscountRate	0.12
CY2023	us-gaap	Variable Lease Payment VariableLeasePayment	100000	usd
CY2021Q4	slrn	Temporary Equity Stock Issued During Period Threshold Trading Days TemporaryEquityStockIssuedDuringPeriodThresholdTradingDays	15	day
CY2023Q2	slrn	Temporary Equity Convertible Conversion Ratio TemporaryEquityConvertibleConversionRatio	1
CY2022Q4	us-gaap	Temporary Equity Shares Authorized TemporaryEquitySharesAuthorized	104461636	shares
CY2022Q4	us-gaap	Temporary Equity Shares Issued TemporaryEquitySharesIssued	40743522	shares
CY2022Q4	us-gaap	Temporary Equity Shares Outstanding TemporaryEquitySharesOutstanding	40743522	shares
CY2022Q4	us-gaap	Temporary Equity Liquidation Preference TemporaryEquityLiquidationPreference	408000000	usd
CY2022Q4	us-gaap	Temporary Equity Carrying Amount Attributable To Parent TemporaryEquityCarryingAmountAttributableToParent	396593000	usd
CY2023	slrn	Temporary Equity Conversion Event Proceeds Minimum Threshold TemporaryEquityConversionEventProceedsMinimumThreshold	3000000	usd
CY2023	us-gaap	Gain Loss On Derivative Instruments Net Pretax GainLossOnDerivativeInstrumentsNetPretax	10300000	usd
CY2023Q4	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	20101379	shares
CY2022Q4	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	48458034	shares
CY2020Q3	us-gaap	Stock Issued During Period Shares Issued For Services StockIssuedDuringPeriodSharesIssuedForServices	2839749	shares
CY2020Q3	us-gaap	Sale Of Stock Price Per Share SaleOfStockPricePerShare	0.00002
CY2023Q2	slrn	Share Based Compensation Arrangement By Share Based Payment Award And Cash Based Compensation Maximum ShareBasedCompensationArrangementByShareBasedPaymentAwardAndCashBasedCompensationMaximum	750000	usd
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	5036946	shares
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	4.7872
CY2022	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Remaining Contractual Term2 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2	P9Y6M
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	5488000	usd
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	6196917	shares
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	14.9001
CY2023	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	330506	shares
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	5.1507
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	10653	shares
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	18.0000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	1262081	shares
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	10.9333
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	9630623	shares
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	10.4619
CY2023	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Remaining Contractual Term2 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2	P9Y
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	12007000	usd
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	1661322	shares
CY2023Q4	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Exercisable Options Weighted Average Exercise Price1 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1	4.4577
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P8Y1M6D
CY2023Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	5226000	usd
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber	9630623	shares
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice	10.4619
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1	P9Y
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue	12007000	usd
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	10600000	usd
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	8.8732
CY2023	us-gaap	Stock Issued During Period Shares Employee Stock Purchase Plans StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans	24164	shares
CY2023	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	100000	usd
CY2023	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	47318000	usd
CY2022	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	4052000	usd
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	233000	usd
CY2023	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	47318000	usd
CY2022	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	4052000	usd
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	233000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	-381641000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	-64772000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-41839000	usd
CY2023	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	70647093	shares
CY2022	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	3271978	shares
CY2021	us-gaap	Weighted Average Number Of Shares Issued Basic WeightedAverageNumberOfSharesIssuedBasic	2843305	shares
CY2023	us-gaap	Weighted Average Number Of Shares Common Stock Subject To Repurchase Or Cancellation WeightedAverageNumberOfSharesCommonStockSubjectToRepurchaseOrCancellation	397513	shares
CY2022	us-gaap	Weighted Average Number Of Shares Common Stock Subject To Repurchase Or Cancellation WeightedAverageNumberOfSharesCommonStockSubjectToRepurchaseOrCancellation	1714444	shares
CY2021	us-gaap	Weighted Average Number Of Shares Common Stock Subject To Repurchase Or Cancellation WeightedAverageNumberOfSharesCommonStockSubjectToRepurchaseOrCancellation	2155907	shares
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	70249580	shares
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	70249580	shares
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	1557534	shares
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	1557534	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	687398	shares
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	687398	shares
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-5.43
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-5.43
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-41.59
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-41.59
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-60.87
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-60.87
CY2023	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	13029495	shares
CY2022	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	47449713	shares
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	18542553	shares
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	0	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	0	usd
CY2023	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.2100
CY2022	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.2100
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	0.0007
CY2022	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.0071
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.0026
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.0103
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.0043
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.0011
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	-0.0112
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	-0.0140
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	-0.0019
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.1438
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.2268
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.2134
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Research And Development EffectiveIncomeTaxRateReconciliationNondeductibleExpenseResearchAndDevelopment	-0.0678
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Research And Development EffectiveIncomeTaxRateReconciliationNondeductibleExpenseResearchAndDevelopment	0
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Research And Development EffectiveIncomeTaxRateReconciliationNondeductibleExpenseResearchAndDevelopment	0
CY2023	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0
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	19640000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	6203000	usd
CY2023Q4	slrn	Deferred Tax Assets Capitalized Research And Experimental Expenditures DeferredTaxAssetsCapitalizedResearchAndExperimentalExpenditures	52911000	usd
CY2022Q4	slrn	Deferred Tax Assets Capitalized Research And Experimental Expenditures DeferredTaxAssetsCapitalizedResearchAndExperimentalExpenditures	10814000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Goodwill And Intangible Assets DeferredTaxAssetsGoodwillAndIntangibleAssets	14439000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Goodwill And Intangible Assets DeferredTaxAssetsGoodwillAndIntangibleAssets	4785000	usd
CY2023Q4	slrn	Deferred Tax Assets Research Credits DeferredTaxAssetsResearchCredits	6898000	usd
CY2022Q4	slrn	Deferred Tax Assets Research Credits DeferredTaxAssetsResearchCredits	1259000	usd
CY2023Q4	slrn	Deferred Tax Assets Lease Liabilities DeferredTaxAssetsLeaseLiabilities	298000	usd
CY2022Q4	slrn	Deferred Tax Assets Lease Liabilities DeferredTaxAssetsLeaseLiabilities	0	usd
CY2023Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	4782000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	676000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	98968000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	23737000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	98716000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	23737000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	252000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	0	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	252000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	0	usd
CY2023Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	252000	usd
CY2022Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	0	usd
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	0	usd
CY2022Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	0	usd
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	100000	usd
CY2023	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	75000000	usd
CY2022	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	14700000	usd
CY2021	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	8900000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	516000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	48000	usd
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	usd
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1600000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	468000	usd
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	48000	usd
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	233000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	2348000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	516000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	48000	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	0	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	0	usd

Files In Submission

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0001962918-24-000032-index.html	Edgar Link	pending
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$SLRN
ACELYRIN, Inc. Stock $slrn

2024 Q1 Form 10-K Financial Statement

#000196291824000032 Filed on March 28, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SLRN ACELYRIN, Inc. Stock $slrn

2024 Q1 Form 10-K Financial Statement

#000196291824000032 Filed on March 28, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$SLRN
ACELYRIN, Inc. Stock $slrn