3.22.2 html 107 213 1 false 31 0 false 5 false false R1.htm 100000 - Document - Document and Entity Information Sheet http://rallybio.com/20220630/taxonomy/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 100010 - Statement - Condensed Consolidated Balance Sheets (Unaudited) Sheet http://rallybio.com/20220630/taxonomy/role/StatementCondensedConsolidatedBalanceSheetsUnaudited Condensed Consolidated Balance Sheets (Unaudited) Statements 2 false false R3.htm 100030 - Statement - Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) Sheet http://rallybio.com/20220630/taxonomy/role/StatementCondensedConsolidatedBalanceSheetsParentheticalUnaudited Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) Statements 3 false false R4.htm 100040 - Statement - Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) Sheet http://rallybio.com/20220630/taxonomy/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLossUnaudited Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) Statements 4 false false R5.htm 100050 - Statement - Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) Sheet http://rallybio.com/20220630/taxonomy/role/StatementCondensedConsolidatedStatementsOfChangesInStockholdersEquityUnaudited Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) Statements 5 false false R6.htm 100060 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited) Sheet http://rallybio.com/20220630/taxonomy/role/StatementCondensedConsolidatedStatementsOfCashFlowsUnaudited Condensed Consolidated Statements of Cash Flows (Unaudited) Statements 6 false false R7.htm 100080 - Disclosure - Business and Liquidity Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureBusinessAndLiquidity Business and Liquidity Notes 7 false false R8.htm 100090 - Disclosure - Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesBasisOfPresentationAndPrinciplesOfConsolidation1 Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation Notes 8 false false R9.htm 100100 - Disclosure - Asset Acquisitions Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureAssetAcquisitions Asset Acquisitions Notes 9 false false R10.htm 100110 - Disclosure - Marketable Securities Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureMarketableSecurities Marketable Securities Notes 10 false false R11.htm 100120 - Disclosure - Fair Value Measurements Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureFairValueMeasurements1 Fair Value Measurements Notes 11 false false R12.htm 100130 - Disclosure - Leases Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureLeases Leases Notes 12 false false R13.htm 100140 - Disclosure - Accrued Expenses Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureAccruedExpenses Accrued Expenses Notes 13 false false R14.htm 100150 - Disclosure - Stockholders' Equity Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureStockholdersEquity1 Stockholders' Equity Notes 14 false false R15.htm 100190 - Disclosure - Investment In Joint Venture Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureInvestmentInJointVenture Investment In Joint Venture Notes 15 false false R16.htm 100200 - Disclosure - Commitments and Contingencies Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureCommitmentsAndContingencies Commitments and Contingencies Notes 16 false false R17.htm 100210 - Disclosure - Net Loss Per Common Share Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureNetLossPerCommonShare1 Net Loss Per Common Share Notes 17 false false R18.htm 100220 - Disclosure - Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation (Policies) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesBasisOfPresentationAndPrinciplesOfConsolidationPolicies Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation (Policies) Policies http://rallybio.com/20220630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesBasisOfPresentationAndPrinciplesOfConsolidation1 18 false false R19.htm 100240 - Disclosure - Marketable Securities (Tables) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureMarketableSecuritiesTables Marketable Securities (Tables) Tables http://rallybio.com/20220630/taxonomy/role/DisclosureMarketableSecurities 19 false false R20.htm 100250 - Disclosure - Fair Value Measurements (Tables) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureFairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://rallybio.com/20220630/taxonomy/role/DisclosureFairValueMeasurements1 20 false false R21.htm 100260 - Disclosure - Leases (Tables) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureLeasesTables Leases (Tables) Tables http://rallybio.com/20220630/taxonomy/role/DisclosureLeases 21 false false R22.htm 100270 - Disclosure - Accrued Expenses (Tables) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureAccruedExpensesTables Accrued Expenses (Tables) Tables http://rallybio.com/20220630/taxonomy/role/DisclosureAccruedExpenses 22 false false R23.htm 100280 - Disclosure - Stockholder's Equity (Tables) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureStockholdersEquityTables Stockholder's Equity (Tables) Tables 23 false false R24.htm 100300 - Disclosure - Net Loss Per Common Share (Tables) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureNetLossPerCommonShareTables Net Loss Per Common Share (Tables) Tables http://rallybio.com/20220630/taxonomy/role/DisclosureNetLossPerCommonShare1 24 false false R25.htm 100310 - Disclosure - Business and Liquidity - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureBusinessAndLiquidityAdditionalInformationDetails Business and Liquidity - Additional Information (Details) Details 25 false false R26.htm 100320 - Disclosure - Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesBasisOfPresentationAndPrinciplesOfConsolidationDetails Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation (Details) Details http://rallybio.com/20220630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesBasisOfPresentationAndPrinciplesOfConsolidationPolicies 26 false false R27.htm 100330 - Disclosure - Asset Acquisitions - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureAssetAcquisitionsAdditionalInformationDetails Asset Acquisitions - Additional Information (Details) Details 27 false false R28.htm 100340 - Disclosure - Marketable Securities - Summary of available-for-sale marketable securities (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureMarketableSecuritiesSummaryOfAvailableforsaleMarketableSecuritiesDetails Marketable Securities - Summary of available-for-sale marketable securities (Details) Details 28 false false R29.htm 100350 - Disclosure - Marketable Securities - Schedule of Available-for-Sale Securities by Balance Sheet Location Classification (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureMarketableSecuritiesScheduleOfAvailableforsaleSecuritiesByBalanceSheetLocationClassificationDetails Marketable Securities - Schedule of Available-for-Sale Securities by Balance Sheet Location Classification (Details) Details 29 false false R30.htm 100360 - Disclosure - Marketable Securities - Schedule of Fair Values of Available-For-Sale Debt Securities By Contractual Maturity (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureMarketableSecuritiesScheduleOfFairValuesOfAvailableforsaleDebtSecuritiesByContractualMaturityDetails Marketable Securities - Schedule of Fair Values of Available-For-Sale Debt Securities By Contractual Maturity (Details) Details 30 false false R31.htm 100370 - Disclosure - Marketable Securities - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureMarketableSecuritiesAdditionalInformationDetails Marketable Securities - Additional Information (Details) Details 31 false false R32.htm 100380 - Disclosure - Fair Value Measurements - Summary of Fair Value Measurements on a Recurring Basis and Level of Inputs (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfFairValueMeasurementsOnARecurringBasisAndLevelOfInputsDetails Fair Value Measurements - Summary of Fair Value Measurements on a Recurring Basis and Level of Inputs (Details) Details 32 false false R33.htm 100390 - Disclosure - Fair Value Measurements - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetails Fair Value Measurements - Additional Information (Details) Details 33 false false R34.htm 100400 - Disclosure - Leases - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureLeasesAdditionalInformationDetails Leases - Additional Information (Details) Details 34 false false R35.htm 100410 - Disclosure - Leases - Summary of company's operating lease on the condensed consolidated balance sheets (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureLeasesSummaryOfCompanysOperatingLeaseOnTheCondensedConsolidatedBalanceSheetsDetails Leases - Summary of company's operating lease on the condensed consolidated balance sheets (Details) Details 35 false false R36.htm 100420 - Disclosure - Leases - Schedule of Future Minimum Annual Lease Payments (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureLeasesScheduleOfFutureMinimumAnnualLeasePaymentsDetails Leases - Schedule of Future Minimum Annual Lease Payments (Details) Details 36 false false R37.htm 100430 - Disclosure - Accrued Expenses - Schedule Of Accrued Expenses (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureAccruedExpensesScheduleOfAccruedExpensesDetails Accrued Expenses - Schedule Of Accrued Expenses (Details) Details 37 false false R38.htm 100440 - Disclosure - Stockholders' Equity - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureStockholdersEquityAdditionalInformationDetails Stockholders' Equity - Additional Information (Details) Details 38 false false R39.htm 100450 - Disclosure - Stockholders' Equity - Summary of Equity-based Compensation (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureStockholdersEquitySummaryOfEquitybasedCompensationDetails Stockholders' Equity - Summary of Equity-based Compensation (Details) Details 39 false false R40.htm 100460 - Disclosure - Stockholder's Equity - Summary of stock option activity (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureStockholdersEquitySummaryOfStockOptionActivityDetails Stockholder's Equity - Summary of stock option activity (Details) Details 40 false false R41.htm 100470 - Disclosure - Stockholder's Equity - Summary of Assumptions of Fair Value of Option Pricing Granted (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureStockholdersEquitySummaryOfAssumptionsOfFairValueOfOptionPricingGrantedDetails Stockholder's Equity - Summary of Assumptions of Fair Value of Option Pricing Granted (Details) Details 41 false false R42.htm 100480 - Disclosure - Stockholder's Equity - Summary of Nonvested Restricted Common Stock Awards (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureStockholdersEquitySummaryOfNonvestedRestrictedCommonStockAwardsDetails Stockholder's Equity - Summary of Nonvested Restricted Common Stock Awards (Details) Details 42 false false R43.htm 100490 - Disclosure - Stockholder's Equity - Summary of Nonvested Restricted Common Stock Units (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureStockholdersEquitySummaryOfNonvestedRestrictedCommonStockUnitsDetails Stockholder's Equity - Summary of Nonvested Restricted Common Stock Units (Details) Details 43 false false R44.htm 100540 - Disclosure - Investment In Joint Venture - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureInvestmentInJointVentureAdditionalInformationDetails Investment In Joint Venture - Additional Information (Details) Details 44 false false R45.htm 100550 - Disclosure - Commitments and Contingencies - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails Commitments and Contingencies - Additional Information (Details) Details 45 false false R46.htm 100560 - Disclosure - Net Loss Per Common Share - Summary of Basic and diluted loss per common share (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureNetLossPerCommonShareSummaryOfBasicAndDilutedLossPerCommonShareDetails Net Loss Per Common Share - Summary of Basic and diluted loss per common share (Details) Details 46 false false R47.htm 100570 - Disclosure - Net Loss Per Common Share - Additional Information (Details) Sheet http://rallybio.com/20220630/taxonomy/role/DisclosureNetLossPerCommonShareAdditionalInformationDetails Net Loss Per Common Share - Additional Information (Details) Details 47 false false All Reports Book All Reports rlyb-20220630.htm rlyb-20220630.xsd rlyb-20220630_cal.xml rlyb-20220630_def.xml rlyb-20220630_lab.xml rlyb-20220630_pre.xml rlyb-ex10_1.htm rlyb-ex31_1.htm rlyb-ex31_2.htm rlyb-ex32_1.htm rlyb-ex32_2.htm img114778283_0.jpg http://fasb.org/us-gaap/2022 http://xbrl.sec.gov/dei/2022 true true