$MRSN
Mersana Therapeutics, Inc. Stock $mrsn

$mrsn Overview Financials Valuation SEC Filings Company Website

2020 Q4 Form 10-Q Financial Statement

#000162828020016044 Filed on November 09, 2020

Income Statement

Concept	2020 Q4	2020 Q3	2019 Q3
Revenue	$10.00K	$11.00K	$844.0K
YoY Change	-76.19%	-98.7%	-60.74%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin	$5.910M	$5.880M	$4.440M
YoY Change	40.38%	32.43%	1.37%
% of Gross Profit
Research & Development	$22.86M	$16.55M	$13.70M
YoY Change	83.89%	20.76%	-9.74%
% of Gross Profit
Depreciation & Amortization	$260.0K	$260.0K	$310.0K
YoY Change	-10.34%	-16.13%	-8.82%
% of Gross Profit
Operating Expenses	$28.77M	$22.43M	$18.14M
YoY Change	72.89%	23.65%	-7.28%
Operating Profit
YoY Change
Interest Expense	$92.00K	$92.00K	$107.0K
YoY Change	5.75%	-14.02%	-68.53%
% of Operating Profit
Other Income/Expense, Net	-$82.00K	-$73.00K	$501.0K
YoY Change	-123.16%	-114.57%
Pretax Income	-$28.84M	-$22.49M	-$16.79M
YoY Change	77.48%	33.95%	-1.64%
Income Tax
% Of Pretax Income
Net Earnings	-$28.84M	-$22.49M	-$16.79M
YoY Change	77.55%	33.93%	-1.63%
Net Earnings / Revenue	-288440.0%	-204445.45%	-1989.57%
Basic Earnings Per Share	-$0.42	-$0.33	-$0.35
Diluted Earnings Per Share	-$0.42	-$0.33	-$0.35
COMMON SHARES
Basic Shares Outstanding	68.50M shares	68.42M shares	47.83M shares
Diluted Shares Outstanding		68.42M shares	47.83M shares

Balance Sheet

Concept	2020 Q4	2020 Q3	2019 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments	$255.1M	$270.9M	$112.0M
YoY Change	155.63%	141.91%	30.08%
Cash & Equivalents	$255.1M	$270.9M	$58.20M
Short-Term Investments	$0.00	$0.00	$53.80M
Other Short-Term Assets	$3.500M	$4.000M	$2.400M
YoY Change	133.33%	66.67%	-29.41%
Inventory
Prepaid Expenses
Receivables			$300.0K
Other Receivables			$0.00
Total Short-Term Assets	$258.6M	$274.9M	$114.7M
YoY Change	155.2%	139.7%	27.44%
LONG-TERM ASSETS
Property, Plant & Equipment	$1.730M	$1.698M	$5.500M
YoY Change	-20.06%	-69.13%	120.0%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets	$2.153M	$2.153M	$1.500M
YoY Change	48.18%	43.53%	-16.67%
Total Long-Term Assets	$14.82M	$15.19M	$7.000M
YoY Change	138.44%	117.06%	59.09%
TOTAL ASSETS
Total Short-Term Assets	$258.6M	$274.9M	$114.7M
Total Long-Term Assets	$14.82M	$15.19M	$7.000M
Total Assets	$273.4M	$290.1M	$121.7M
YoY Change	154.23%	138.4%	28.92%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$8.340M	$4.528M	$7.300M
YoY Change	14.31%	-37.97%	8.96%
Accrued Expenses	$16.15M	$11.17M	$10.20M
YoY Change	79.68%	9.54%	-2.86%
Deferred Revenue	$3.987M	$3.998M
YoY Change	-17.2%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$0.00	$0.00	$300.0K
YoY Change	-100.0%	-100.0%
Total Short-Term Liabilities	$30.00M	$21.07M	$22.40M
YoY Change	24.65%	-5.94%	-28.66%
LONG-TERM LIABILITIES
Long-Term Debt	$4.977M	$4.944M	$5.000M
YoY Change	18.47%	-1.12%
Other Long-Term Liabilities	$174.0K	$200.0K	$1.300M
YoY Change	-36.73%	-84.62%	-96.07%
Total Long-Term Liabilities	$5.151M	$5.144M	$6.300M
YoY Change	15.08%	-18.35%	-80.97%
TOTAL LIABILITIES
Total Short-Term Liabilities	$30.00M	$21.07M	$22.40M
Total Long-Term Liabilities	$5.151M	$5.144M	$6.300M
Total Liabilities	$45.31M	$36.82M	$28.60M
YoY Change	55.06%	28.74%	-55.66%
SHAREHOLDERS EQUITY
Retained Earnings	-$280.4M	-$251.6M
YoY Change	45.77%
Common Stock	$508.5M	$504.9M
YoY Change	87.87%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$228.1M	$253.3M	$93.05M
YoY Change
Total Liabilities & Shareholders Equity	$273.4M	$290.1M	$121.7M
YoY Change	154.23%	138.4%	28.92%

Cashflow Statement

Concept	2020 Q4	2020 Q3	2019 Q3
OPERATING ACTIVITIES
Net Income	-$28.84M	-$22.49M	-$16.79M
YoY Change	77.55%	33.93%	-1.63%
Depreciation, Depletion And Amortization	$260.0K	$260.0K	$310.0K
YoY Change	-10.34%	-16.13%	-8.82%
Cash From Operating Activities	-$17.32M	-$20.20M	-$16.29M
YoY Change	37.79%	24.0%	55.59%
INVESTING ACTIVITIES
Capital Expenditures	-$180.0K	-$200.0K	-$30.00K
YoY Change		566.67%	-88.89%
Acquisitions
YoY Change
Other Investing Activities	$0.00	$3.000M	-$41.74M
YoY Change	-100.0%	-107.19%	-298.76%
Cash From Investing Activities	-$190.0K	$2.810M	-$41.76M
YoY Change	-101.15%	-106.73%	-301.54%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	1.660M	-50.00K	-10.00K
YoY Change	621.74%	400.0%	-104.76%
NET CHANGE
Cash From Operating Activities	-17.32M	-20.20M	-16.29M
Cash From Investing Activities	-190.0K	2.810M	-41.76M
Cash From Financing Activities	1.660M	-50.00K	-10.00K
Net Change In Cash	-15.85M	-17.44M	-58.06M
YoY Change	-481.01%	-69.96%	-655.07%
FREE CASH FLOW
Cash From Operating Activities	-$17.32M	-$20.20M	-$16.29M
Capital Expenditures	-$180.0K	-$200.0K	-$30.00K
Free Cash Flow	-$17.14M	-$20.00M	-$16.26M
YoY Change	36.36%	23.0%	59.41%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Entity Central Index Key EntityCentralIndexKey	0001442836
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q3
	dei	Amendment Flag AmendmentFlag	false
	us-gaap	Substantial Doubt About Going Concern Within One Year SubstantialDoubtAboutGoingConcernWithinOneYear	false
CY2019Q4	us-gaap	Restricted Cash Asset Statement Of Financial Position Extensible List RestrictedCashAssetStatementOfFinancialPositionExtensibleList	us-gaap:OtherAssetsNoncurrent
CY2020Q3	us-gaap	Restricted Cash Asset Statement Of Financial Position Extensible List RestrictedCashAssetStatementOfFinancialPositionExtensibleList	us-gaap:OtherAssetsNoncurrent
CY2019Q3	us-gaap	Revenue From Contract With Customer Product And Service Extensible List RevenueFromContractWithCustomerProductAndServiceExtensibleList	mrsn:CollaborationMember
CY2020Q3	us-gaap	Revenue From Contract With Customer Product And Service Extensible List RevenueFromContractWithCustomerProductAndServiceExtensibleList	mrsn:CollaborationMember
	dei	Document Type DocumentType	10-Q
	dei	Document Period End Date DocumentPeriodEndDate	2020-09-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	001-38129
	dei	Entity Registrant Name EntityRegistrantName	Mersana Therapeutics, Inc.
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	04-3562403
	dei	Entity Address Address Line1 EntityAddressAddressLine1	840 Memorial Drive
	dei	Entity Address City Or Town EntityAddressCityOrTown	Cambridge
	dei	Entity Address State Or Province EntityAddressStateOrProvince	MA
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	02139
	dei	City Area Code CityAreaCode	617
	dei	Local Phone Number LocalPhoneNumber	498-0020
	dei	Security12b Title Security12bTitle	Common Stock, $0.0001 par value
	dei	Trading Symbol TradingSymbol	MRSN
	dei	Security Exchange Name SecurityExchangeName	NASDAQ
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Filer Category EntityFilerCategory	Accelerated Filer
	dei	Entity Small Business EntitySmallBusiness	true
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	true
	dei	Entity Ex Transition Period EntityExTransitionPeriod	true
	dei	Entity Shell Company EntityShellCompany	false
CY2020Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	68497425	shares
CY2020Q3	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	2153000	USD
CY2020Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	270936000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	62351000	USD
CY2020Q3	us-gaap	Available For Sale Securities Debt Securities Current AvailableForSaleSecuritiesDebtSecuritiesCurrent	0	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities Current AvailableForSaleSecuritiesDebtSecuritiesCurrent	37439000	USD
CY2020Q3	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	3998000	USD
CY2019Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	1536000	USD
CY2020Q3	us-gaap	Assets Current AssetsCurrent	274934000	USD
CY2019Q4	us-gaap	Assets Current AssetsCurrent	101326000	USD
CY2020Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	1698000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	2164000	USD
CY2020Q3	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	11343000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	2598000	USD
CY2019Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	1453000	USD
CY2020Q3	us-gaap	Assets Assets	290128000	USD
CY2019Q4	us-gaap	Assets Assets	107541000	USD
CY2020Q3	us-gaap	Accounts Payable Current AccountsPayableCurrent	4528000	USD
CY2019Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	7296000	USD
CY2020Q3	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	11173000	USD
CY2019Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	8986000	USD
CY2020Q3	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	3998000	USD
CY2019Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	4815000	USD
CY2020Q3	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	1280000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	2219000	USD
CY2020Q3	us-gaap	Long Term Debt Current LongTermDebtCurrent	0	USD
CY2019Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	667000	USD
CY2020Q3	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	91000	USD
CY2019Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	87000	USD
CY2020Q3	us-gaap	Liabilities Current LiabilitiesCurrent	21070000	USD
CY2019Q4	us-gaap	Liabilities Current LiabilitiesCurrent	24070000	USD
CY2020Q3	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	10606000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	677000	USD
CY2020Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	4944000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	4201000	USD
CY2020Q3	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	200000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	275000	USD
CY2020Q3	us-gaap	Liabilities Liabilities	36820000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	29223000	USD
CY2020Q3	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.0001
CY2020Q3	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.0001
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	25000000	shares
CY2020Q3	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	25000000	shares
CY2020Q3	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2019Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2020Q3	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	9980000	USD
CY2020Q3	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2020Q3	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2019Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2020Q3	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.0001
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.0001
CY2020Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	175000000	shares
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	175000000	shares
CY2020Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	68470081	shares
CY2020Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	68470081	shares
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	45388023	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	45388023	shares
CY2020Q3	us-gaap	Common Stock Value CommonStockValue	7000	USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	5000	USD
CY2020Q3	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	504876000	USD
CY2019Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	270662000	USD
CY2020Q3	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	5881000	USD
CY2019Q3	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	4436000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	0	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	25000	USD
CY2020Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-251575000	USD
CY2019Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-192374000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	253308000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	78318000	USD
CY2020Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	290128000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	107541000	USD
CY2020Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	11000	USD
CY2019Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	844000	USD
	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	817000	USD
	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	42081000	USD
CY2020Q3	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	16546000	USD
CY2019Q3	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	13701000	USD
	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	44179000	USD
	us-gaap	Research And Development Expense ResearchAndDevelopmentExpense	42610000	USD
	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	15988000	USD
	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	13072000	USD
CY2020Q3	us-gaap	Operating Expenses OperatingExpenses	22427000	USD
CY2019Q3	us-gaap	Operating Expenses OperatingExpenses	18137000	USD
	us-gaap	Operating Expenses OperatingExpenses	60167000	USD
	us-gaap	Operating Expenses OperatingExpenses	55682000	USD
CY2020Q3	us-gaap	Investment Income Interest InvestmentIncomeInterest	19000	USD
CY2019Q3	us-gaap	Investment Income Interest InvestmentIncomeInterest	608000	USD
	us-gaap	Investment Income Interest InvestmentIncomeInterest	414000	USD
	us-gaap	Investment Income Interest InvestmentIncomeInterest	1785000	USD
CY2020Q3	us-gaap	Interest Expense InterestExpense	92000	USD
CY2019Q3	us-gaap	Interest Expense InterestExpense	107000	USD
	us-gaap	Interest Expense InterestExpense	267000	USD
	us-gaap	Interest Expense InterestExpense	146000	USD
CY2020Q3	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-73000	USD
CY2019Q3	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	501000	USD
	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	147000	USD
	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	1639000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	-22489000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	-16792000	USD
	us-gaap	Net Income Loss NetIncomeLoss	-59203000	USD
	us-gaap	Net Income Loss NetIncomeLoss	-11962000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-2000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	17000	USD
	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-25000	USD
	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	36000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-22491000	USD
CY2019Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-16775000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-59228000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-11926000	USD
CY2020Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-22489000	USD
CY2020Q3	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	-22489000	USD
CY2019Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-16792000	USD
CY2019Q3	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	-16792000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-59203000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	-59203000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-11962000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	-11962000	USD
CY2020Q3	us-gaap	Earnings Per Share Basic And Diluted EarningsPerShareBasicAndDiluted	-0.33
CY2019Q3	us-gaap	Earnings Per Share Basic And Diluted EarningsPerShareBasicAndDiluted	-0.35
	us-gaap	Earnings Per Share Basic And Diluted EarningsPerShareBasicAndDiluted	-1.00
	us-gaap	Earnings Per Share Basic And Diluted EarningsPerShareBasicAndDiluted	-0.28
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	68419192	shares
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	68419192	shares
CY2019Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	47833607	shares
CY2019Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	47833607	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	59086202	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	59086202	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	42011340	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	42011340	shares
CY2019Q1	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	1164000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	21901000	USD
CY2019Q1	us-gaap	Stockholders Equity StockholdersEquity	124072000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	8000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	8795000	USD
CY2019Q1	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	42000	USD
CY2019Q1	mrsn	Stock Issuance Discounts And Commissions On Transaction StockIssuanceDiscountsAndCommissionsOnTransaction	5587000	USD
CY2019Q1	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	92162000	USD
CY2019Q2	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	58000	USD
CY2019Q2	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition	283000	USD
CY2019Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	1161000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	11000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	-17071000	USD
CY2019Q2	us-gaap	Stockholders Equity StockholdersEquity	108514000	USD
CY2019Q3	mrsn	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	21000	USD
CY2019Q3	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	1285000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	17000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	-16792000	USD
CY2019Q3	us-gaap	Stockholders Equity StockholdersEquity	93045000	USD
CY2019Q4	mrsn	Stock Retired During Period Exchanged For Common Stock Warrant Value StockRetiredDuringPeriodExchangedForCommonStockWarrantValue	8986000	USD
CY2019Q4	us-gaap	Adjustments To Additional Paid In Capital Warrant Issued AdjustmentsToAdditionalPaidInCapitalWarrantIssued	8986000	USD
CY2019Q4	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition	206000	USD
CY2019Q4	mrsn	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	54000	USD
CY2019Q4	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	1262000	USD
CY2019Q4	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-3000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	-16246000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	78318000	USD
CY2020Q1	mrsn	Stock Issued During Period Shares Of Common Stock Warrants In Exchange For Common Stock Exercised StockIssuedDuringPeriodSharesOfCommonStockWarrantsInExchangeForCommonStockExercised	0	shares
CY2020Q1	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	119000	USD
CY2020Q1	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	1609000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-29000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	-16926000	USD
CY2020Q1	us-gaap	Stockholders Equity StockholdersEquity	63091000	USD
CY2020Q2	us-gaap	Adjustments To Additional Paid In Capital Share Based Compensation Employee Stock Purchase Program Requisite Service Period Recognition AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationEmployeeStockPurchaseProgramRequisiteServicePeriodRecognition	333000	USD
CY2020Q2	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	1296000	USD
CY2020Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	1656000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	6000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	-19786000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	273564000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	317000	USD
CY2020Q3	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	1918000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-2000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	-22489000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	253308000	USD
	us-gaap	Profit Loss ProfitLoss	-59203000	USD
	us-gaap	Profit Loss ProfitLoss	-11962000	USD
	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	750000	USD
	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	963000	USD
	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-2766000	USD
	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-3102000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	86000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	87000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	5183000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	3610000	USD
	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-110000	USD
	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-65000	USD
	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	0	USD
	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-161000	USD
	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	2460000	USD
	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-1318000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	700000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	0	USD
	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	2367000	USD
	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	-4518000	USD
	mrsn	Increase Decrease In Operating Lease Assets IncreaseDecreaseInOperatingLeaseAssets	1235000	USD
	mrsn	Increase Decrease In Operating Lease Assets IncreaseDecreaseInOperatingLeaseAssets	1290000	USD
	mrsn	Increase Decrease In Operating Lease Liabilities IncreaseDecreaseInOperatingLeaseLiabilities	990000	USD
	mrsn	Increase Decrease In Operating Lease Liabilities IncreaseDecreaseInOperatingLeaseLiabilities	1356000	USD
	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	-817000	USD
	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	-41550000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-57377000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-55168000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	37500000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	10500000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	0	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	53688000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	285000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	605000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	37215000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-43793000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	1732000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	121000	USD
	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	333000	USD
	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	283000	USD
	mrsn	Proceeds From Debt Net Issuance Costs ProceedsFromDebtNetIssuanceCosts	-197000	USD
	mrsn	Proceeds From Debt Net Issuance Costs ProceedsFromDebtNetIssuanceCosts	4965000	USD
	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	87000	USD
	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	58000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	228747000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	97473000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	208585000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-1488000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	62672000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	60005000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	271257000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	58517000	USD
	us-gaap	Debt Issuance Costs Incurred During Noncash Or Partial Noncash Transaction DebtIssuanceCostsIncurredDuringNoncashOrPartialNoncashTransaction	0	USD
	us-gaap	Debt Issuance Costs Incurred During Noncash Or Partial Noncash Transaction DebtIssuanceCostsIncurredDuringNoncashOrPartialNoncashTransaction	180000	USD
	us-gaap	Interest Paid Net InterestPaidNet	173000	USD
	us-gaap	Interest Paid Net InterestPaidNet	64000	USD
	us-gaap	Net Income Loss NetIncomeLoss	-59203000	USD
	us-gaap	Net Income Loss NetIncomeLoss	-11962000	USD
CY2020Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-251575000	USD
	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	4778000	USD
	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	0	USD
	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	429000	USD
	us-gaap	Use Of Estimates UseOfEstimates	<div style="margin-bottom:12pt"><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-bottom:12pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The preparation of the Company’s unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenue, expenses and related disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenue and expenses during the reporting period. On an ongoing basis, the Company’s management evaluates its estimates which include, but are not limited to, management’s judgments with respect to the identification of performance obligations and standalone selling prices of those performance obligations within its revenue arrangements, accrued expenses, valuation of stock-based awards and income taxes. Actual results could differ from those estimates.</span></div>
CY2018Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	371000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	62351000	USD
CY2020Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	270936000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	59634000	USD
CY2019Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	58196000	USD
CY2019Q4	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	321000	USD
CY2020Q3	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	321000	USD
CY2019Q3	us-gaap	Restricted Cash Noncurrent RestrictedCashNoncurrent	321000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	62672000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	271257000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	60005000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	58517000	USD
CY2020Q3	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	2153000	USD
CY2019Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	1453000	USD
CY2020Q3	us-gaap	Retainage Deposit RetainageDeposit	1832000	USD
CY2019Q4	us-gaap	Retainage Deposit RetainageDeposit	1132000	USD
CY2020Q3	us-gaap	Security Deposit SecurityDeposit	321000	USD
CY2019Q4	us-gaap	Security Deposit SecurityDeposit	321000	USD
CY2019Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	5205407	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	6995704	shares
CY2020Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	6995704	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	5205407	shares
	us-gaap	Revenue Performance Obligation Description Of Timing RevenuePerformanceObligationDescriptionOfTiming	Revenue related to future technological improvements and joint research committee services will be recognized ratably over the respective performance period (which in the case of the joint research committee services approximates the time and cost incurred each period), which are 10 and five years, respectively.
CY2019Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2020Q3	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2019Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	4815000	USD
	mrsn	Contract With Customer Liability Increase ContractWithCustomerLiabilityIncrease	0	USD
	mrsn	Contract With Customer Liability Decrease ContractWithCustomerLiabilityDecrease	817000	USD
CY2020Q3	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	3998000	USD
CY2018Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2019Q3	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2018Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	46196000	USD
	mrsn	Contract With Customer Liability Increase ContractWithCustomerLiabilityIncrease	0	USD
	mrsn	Contract With Customer Liability Decrease ContractWithCustomerLiabilityDecrease	41550000	USD
CY2019Q3	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	4646000	USD
CY2020Q3	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	11000	USD
CY2019Q3	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	834000	USD
	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	817000	USD
	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	41550000	USD
CY2020Q3	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0	USD
CY2019Q3	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0	USD
	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0	USD
	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	0	security
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	37414000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	25000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	0	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	37439000	USD
CY2020Q3	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	3647000	USD
CY2019Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	4037000	USD
CY2020Q3	mrsn	Accrued Preclinical And Clinical Expenses Current AccruedPreclinicalAndClinicalExpensesCurrent	6600000	USD
CY2019Q4	mrsn	Accrued Preclinical And Clinical Expenses Current AccruedPreclinicalAndClinicalExpensesCurrent	4230000	USD
CY2020Q3	mrsn	Accrued Professional Fees And Insurance Current AccruedProfessionalFeesAndInsuranceCurrent	861000	USD
CY2019Q4	mrsn	Accrued Professional Fees And Insurance Current AccruedProfessionalFeesAndInsuranceCurrent	675000	USD
CY2020Q3	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	5200000	USD
CY2020Q3	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	65000	USD
CY2019Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	44000	USD
CY2020Q3	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	11173000	USD
CY2019Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	8986000	USD
CY2020Q3	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	262000	USD
CY2020Q3	us-gaap	Debt Instrument Unamortized Premium DebtInstrumentUnamortizedPremium	6000	USD
CY2020Q3	us-gaap	Long Term Debt LongTermDebt	4944000	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal Remainder Of Fiscal Year LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	1213000	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	2080000	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	1907000	USD
CY2020Q3	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	5200000	USD
CY2020Q3	us-gaap	Interest Expense Debt InterestExpenseDebt	60000	USD
CY2019Q3	us-gaap	Interest Expense Debt InterestExpenseDebt	51000	USD
	us-gaap	Interest Expense Debt InterestExpenseDebt	173000	USD
	us-gaap	Interest Expense Debt InterestExpenseDebt	64000	USD
CY2020Q3	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	25000000	shares
CY2020Q3	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2013	mrsn	Class Of Warrant Or Right Securities Called By Warrants Or Rights Number Issued ClassOfWarrantOrRightSecuritiesCalledByWarrantsOrRightsNumberIssued	129491	shares
CY2013Q4	us-gaap	Class Of Warrant Or Right Exercise Price Of Warrants Or Rights1 ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1	0.05
CY2013	mrsn	Contractual Life Of Warrants ContractualLifeOfWarrants	P10Y
CY2020Q3	us-gaap	Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights	39474	shares
CY2020Q3	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	6995704	shares
CY2019Q4	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	7782582	shares
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	4.87
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	1960374	shares
CY2020Q3	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	6995704	shares
CY2019Q4	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	7782582	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	4720772	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	5.24
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	9.41
	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	338069	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	5.13
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod	127709	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice	7.70
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	6215368	shares
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	6.52
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	3256514	shares
CY2020Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	1918000	USD
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	6.17
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	2.47
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	1732000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	121000	USD
CY2020Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	1918000	USD
CY2019Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	1285000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	5183000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3610000	USD
CY2019Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	1285000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	5183000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3610000	USD
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.004
CY2019Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.019
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.013
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.024
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0
CY2019Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0
CY2020Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y1M6D
CY2019Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y1M9D
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P6Y14D
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P5Y11M26D
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.81
CY2019Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.75
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.72
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.74
CY2020Q1	mrsn	Tenant Improvement Allowance TenantImprovementAllowance	172000	USD
CY2020Q1	mrsn	Lessee Operating Lease Modification Increase Decrease In Operating Lease Liability LesseeOperatingLeaseModificationIncreaseDecreaseInOperatingLeaseLiability	9980000	USD
CY2020Q1	mrsn	Lessee Operating Lease Modification Increase Decrease In Right Of Use Assets LesseeOperatingLeaseModificationIncreaseDecreaseInRightOfUseAssets	9980000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Remainder Of Fiscal Year LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear	604000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Remainder Of Fiscal Year FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear	29000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	2772000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	116000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	2843000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	4165000	USD
CY2020Q3	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	30000	USD
CY2020Q3	us-gaap	Operating Lease Liability OperatingLeaseLiability	11886000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	84000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	2928000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	74000	USD
CY2020Q3	mrsn	Lessee Operating Lease Liability Payments Due Year Four And After Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFourAndAfterYearFour	6904000	USD
CY2020Q3	mrsn	Finance Lease Liability Payments Due Year Four And After Year Four FinanceLeaseLiabilityPaymentsDueYearFourAndAfterYearFour	18000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	16051000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	321000	USD
CY2020Q3	us-gaap	Finance Lease Liability FinanceLeaseLiability	291000	USD
	mrsn	Milestone Payment MilestonePayment	750000	USD
	mrsn	Milestone Payment MilestonePayment	600000	USD
CY2019Q3	mrsn	Milestone Payment MilestonePayment	600000	USD
CY2020Q3	mrsn	Milestone Payment MilestonePayment	0	USD

Files In Submission

Name	View Source	Status
0001628280-20-016044-index-headers.html	Edgar Link	pending
0001628280-20-016044-index.html	Edgar Link	pending
0001628280-20-016044.txt	Edgar Link	pending
0001628280-20-016044-xbrl.zip	Edgar Link	pending
exhibit31110-qfy2020q3.htm	Edgar Link	pending
exhibit31210-qfy2020q3.htm	Edgar Link	pending
exhibit32110-qfy2020q3.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
mrsn-20200930.htm	Edgar Link	pending
mrsn-20200930.xsd	Edgar Link	pending
mrsn-20200930_cal.xml	Edgar Link	unprocessable
mrsn-20200930_def.xml	Edgar Link	unprocessable
mrsn-20200930_htm.xml	Edgar Link	completed
mrsn-20200930_lab.xml	Edgar Link	unprocessable
mrsn-20200930_pre.xml	Edgar Link	unprocessable
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
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

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$MRSN
Mersana Therapeutics, Inc. Stock $mrsn

2020 Q4 Form 10-Q Financial Statement

#000162828020016044 Filed on November 09, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$MRSN Mersana Therapeutics, Inc. Stock $mrsn

2020 Q4 Form 10-Q Financial Statement

#000162828020016044 Filed on November 09, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$MRSN
Mersana Therapeutics, Inc. Stock $mrsn