Novartis Agreement - Additional Information (Details)			1 Months Ended	3 Months Ended			9 Months Ended
	Dec. 19, 2019 USD ($) shares	Dec. 07, 2019 USD ($)	Oct. 31, 2019 USD ($) Research $ / shares	Sep. 30, 2020 USD ($) shares	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) shares
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Preferred stock, shares issued | shares				0			0		0
Series C Redeemable Convertible Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Preferred stock, shares issued | shares				0			0		26,360,745
Novartis | Novartis Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Proceeds from upfront non-refundable license fee		$ 50,000,000
Collaboration and license agreement, description							The Company is initially obligated to perform research and development services on the integrin research targets for sixty days.
Collaboration and license agreement, target validation fee			$ 4,000,000
Committed to provide equity financing			30,000,000
Percentage of outstanding shares of common stock on fully diluted basis				6.10%			6.10%		7.40%
Transaction price of Novartis agreement			69,600,000
Selling price of license			50,000,000
Revenue recognized from related party				$ 4,800,000		$ 0	$ 37,400,000	$ 0
Receivable from related party transactions				7,100,000			7,100,000		$ 7,100,000
Contract assets				0			0		0
Contract liabilities				0			0		$ 0
Novartis | Novartis Agreement | Achievement of First Patient Dosing Milestone
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized from related party					$ 25,000,000
Novartis | Novartis Agreement | License Fee
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price of Novartis agreement			50,000,000
Novartis | Novartis Agreement | Research and Development
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price of Novartis agreement			19,600,000
Revenue recognized from related party				$ 4,800,000			$ 12,400,000
Novartis | Novartis Agreement | Initial Public Offering
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Committed to provide equity financing			10,000,000
Novartis | Novartis Agreement | Series C Redeemable Convertible Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Committed to provide equity financing	$ 20,000,000		$ 20,000,000
Preferred stock, shares issued | shares	10,928,962
Redeemable convertible preferred stock issued at fair value per share | $ / shares			$ 1.83
Purchase of redeemable convertible preferred stock	$ 10,900,000
Novartis | Novartis Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of Integrin research targets | Research			3
Receivable from development services			$ 19,600,000
Collaboration and license agreement, integrin research targets amount			416,000,000
Committed to provide equity financing			$ 30,000,000