Impel Pharmaceuticals (IMPL) S-1 7 Sep 21 IPO registration Financial data

Cover Page

Cover Page	6 Months Ended
	Jun. 30, 2021
Cover [Abstract]
Document Type	S-1
Amendment Flag	false
Entity Registrant Name	IMPEL NEUROPHARMA, INC.
Entity Central Index Key	0001445499
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheet (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 60,948	$ 7,095	$ 37,001
Prepaid expenses and other current assets	4,619	1,077	2,524
Total current assets	65,567	8,172	39,525
Property and equipment, net	3,408	3,700	2,740
Other assets	187	187
Total assets	69,162	12,059	42,265
Current liabilities:
Accounts payable	5,461	4,314	2,725
Accrued liabilities	3,546	3,173	4,231
Current portion of term debt		417
Redeemable convertible preferred stock warrant liabilities		2,622	1,366
Total current liabilities	9,007	10,526	8,322
Convertible notes at fair value		0
Long-term debt	8,857	7,994
Total liabilities	17,864	18,520	8,322
Commitments and contingencies (Note 5)
Redeemable convertible preferred stock, $0.001 par value; — and 204,198,489 shares authorized at June 30, 2021 and December 31, 2020 respectively; — and 202,009,981 shares issued and outstanding at June 30, 2021 and December 31, 2020 respectively; aggregate liquidation preference of $128,922 at December 31, 2020	0	127,039	125,647
Stockholders' equity (deficit):
Preferred stock, $0.001 par value; 10,000,000 and — shares authorized at June 30, 2021 and December 31, 2020, respectively	0	0
Common stock, $0.001 par value; 300,000,000 and 266,833,885 shares authorized at June 30, 2021 and December 31, 2020, respectively; 19,470,914 and 755,478 shares issued and outstanding at June 30, 2021 and December 31, 2020, respectively	19	0	0
Additional paid-in capital	216,314	4,762	760
Accumulated deficit	(165,035)	(138,262)	(92,464)
Total stockholders' equity (deficit)	51,298	(133,500)	(91,704)
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	$ 69,162	$ 12,059	$ 42,265

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheet (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	0	204,198,489	204,198,489
Redeemable convertible preferred stock, shares issued	0	202,009,981	201,335,862
Redeemable convertible preferred stock, shares outstanding	0	202,009,981	201,335,862
Redeemable convertible preferred stock, liquidation preference value		$ 128,922	$ 128,353
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	0
Common stock, par value	$ 0.001	$ 0.001	$ 0.001
Common stock, shares authorized	300,000,000	266,833,885	256,704,917
Common stock, shares issued	19,470,914	755,478	360,115
Common stock, shares outstanding	19,470,914	755,478	360,115

Condensed Consolidated Statemen

Condensed Consolidated Statement of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 6,076	$ 6,832	$ 10,174	$ 13,391	$ 27,285	$ 28,812
General and administrative	8,862	6,127	14,633	9,374	18,049	12,754
Total operating expenses	14,938	12,959	24,807	22,765	45,334	41,566
Loss from operations	(14,938)	(12,959)	(24,807)	(22,765)	(45,334)	(41,566)
Interest income (expense), net					(55)	417
Other (expense) income, net	(544)	36	(1,966)	84	(408)	(680)
Loss before income taxes	(15,482)	(12,923)	(26,773)	(22,681)	(45,797)	(41,829)
Provision (benefit) for income taxes	0	(1)	0	0	(1)	(30)
Net loss and comprehensive loss	(15,482)	(12,922)	(26,773)	(22,681)	(45,798)	(41,859)
Accretion on redeemable convertible preferred stock	0	128	129	256	(518)	(505)
Net loss attributable to common stockholders	$ (15,482)	$ (13,050)	$ (26,902)	$ (22,937)	$ (46,316)	$ (42,364)
Net loss per share attributable to common stockholders, basic and diluted	$ (1.10)	$ (35.88)	$ (3.60)	$ (63.32)	$ (91.05)	$ (122.07)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	14,119,672	363,684	7,475,242	362,246	508,668	347,042

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	Initial public offering	Redeemable Convertible Preferred Stock [Member]	Redeemable Convertible Preferred Stock [Member]Initial public offering	Common Stock	Common StockInitial public offering	Additional Paid-In Capital	Additional Paid-In CapitalInitial public offering	Accumulated Deficit
Beginning Balance at Dec. 31, 2018			$ 125,142
Beginning Balance, Shares at Dec. 31, 2018			201,335,862
Beginning Balance at Dec. 31, 2018	$ (50,155)				$ 0		$ 450		$ (50,605)
Beginning Balance, Shares at Dec. 31, 2018					346,047
Accretion to redemption value on redeemable convertible preferred stock	(505)		$ 505				(505)
Stock-based compensation expense	794						794
Issuance of common stock upon the exercise of stock options	21						21
Issuance of common stock upon the exercise of stock options, Shares					14,068
Net loss and comprehensive loss	(41,859)								(41,859)
Ending Balance at Dec. 31, 2019	$ 125,647		$ 125,647
Ending Balance, Shares at Dec. 31, 2019	201,335,862		201,335,862
Ending Balance at Dec. 31, 2019	$ (91,704)				$ 0		760		(92,464)
Ending Balance, Shares at Dec. 31, 2019					360,115
Accretion to redemption value on redeemable convertible preferred stock	(128)		$ 129				(128)
Stock-based compensation expense	298						298
Issuance of common stock upon the exercise of stock options	8						8
Issuance of common stock upon the exercise of stock options, Shares					3,569
Net loss and comprehensive loss	(9,759)								(9,759)
Ending Balance at Mar. 31, 2020			$ 125,776
Ending Balance, Shares at Mar. 31, 2020			201,335,862
Ending Balance at Mar. 31, 2020	(101,285)				$ 0		938		(102,223)
Ending Balance, Shares at Mar. 31, 2020					363,684
Beginning Balance at Dec. 31, 2019	$ 125,647		$ 125,647
Beginning Balance, Shares at Dec. 31, 2019	201,335,862		201,335,862
Beginning Balance at Dec. 31, 2019	$ (91,704)				$ 0		760		(92,464)
Beginning Balance, Shares at Dec. 31, 2019					360,115
Net loss and comprehensive loss	(22,681)
Ending Balance at Jun. 30, 2020			$ 125,921
Ending Balance, Shares at Jun. 30, 2020			201,371,891
Ending Balance at Jun. 30, 2020	(111,850)				$ 0		3,295		(115,145)
Ending Balance, Shares at Jun. 30, 2020					363,684
Beginning Balance at Dec. 31, 2019	$ 125,647		$ 125,647
Beginning Balance, Shares at Dec. 31, 2019	201,335,862		201,335,862
Beginning Balance at Dec. 31, 2019	$ (91,704)				$ 0		760		(92,464)
Beginning Balance, Shares at Dec. 31, 2019					360,115
Accretion to redemption value on redeemable convertible preferred stock	(518)		$ 518				(518)
Stock-based compensation expense	3,641						3,641
Issuance of common stock upon the exercise of stock options	$ 879						879
Issuance of common stock upon the exercise of stock options, Shares	395,363				395,363
Issuance of Series A-2 redeemable convertible preferred stock upon the exercise of preferred warrants			$ 271
Issuance of Series A-2 redeemable convertible preferred stock upon the exercise of preferred warrants (in shares)			296,008
Issuance of Series B redeemable convertible preferred stock upon exercise of Series B warrants			$ 603
Issuance of Series B redeemable convertible preferred stock upon exercise of Series B warrants, Shares			378,111
Net loss and comprehensive loss	$ (45,798)								(45,798)
Ending Balance at Dec. 31, 2020	$ 127,039		$ 127,039
Ending Balance, Shares at Dec. 31, 2020	202,009,981		202,009,981
Ending Balance at Dec. 31, 2020	$ (133,500)				$ 0		4,762		(138,262)
Ending Balance, Shares at Dec. 31, 2020					755,478
Beginning Balance at Mar. 31, 2020			$ 125,776
Beginning Balance, Shares at Mar. 31, 2020			201,335,862
Beginning Balance at Mar. 31, 2020	(101,285)				$ 0		938		(102,223)
Beginning Balance, Shares at Mar. 31, 2020					363,684
Accretion to redemption value on redeemable convertible preferred stock	(128)		$ 127				(128)
Stock-based compensation expense	2,485						2,485
Issuance of Series A-2 redeemable convertible preferred stock upon the exercise of preferred warrants			$ 18
Issuance of Series A-2 redeemable convertible preferred stock upon the exercise of preferred warrants (in shares)			36,029
Net loss and comprehensive loss	(12,922)								(12,922)
Ending Balance at Jun. 30, 2020			$ 125,921
Ending Balance, Shares at Jun. 30, 2020			201,371,891
Ending Balance at Jun. 30, 2020	(111,850)				$ 0		3,295		(115,145)
Ending Balance, Shares at Jun. 30, 2020					363,684
Beginning Balance at Dec. 31, 2020	$ 127,039		$ 127,039
Beginning Balance, Shares at Dec. 31, 2020	202,009,981		202,009,981
Beginning Balance at Dec. 31, 2020	$ (133,500)				$ 0		4,762		(138,262)
Beginning Balance, Shares at Dec. 31, 2020					755,478
Accretion to redemption value on redeemable convertible preferred stock	(129)		$ 129				(129)
Stock-based compensation expense	493						493
Issuance of common stock upon the exercise of stock options	18						18
Issuance of common stock upon the exercise of stock options, Shares					8,095
Net loss and comprehensive loss	(11,291)								(11,291)
Ending Balance at Mar. 31, 2021			$ 127,168
Ending Balance, Shares at Mar. 31, 2021			202,009,981
Ending Balance at Mar. 31, 2021	(144,409)				$ 0		5,144		(149,553)
Ending Balance, Shares at Mar. 31, 2021					763,573
Beginning Balance at Dec. 31, 2020	$ 127,039		$ 127,039
Beginning Balance, Shares at Dec. 31, 2020	202,009,981		202,009,981
Beginning Balance at Dec. 31, 2020	$ (133,500)				$ 0		4,762		(138,262)
Beginning Balance, Shares at Dec. 31, 2020					755,478
Conversion of convertible notes into common stock at initial public offering	$ 8,393
Issuance of common stock upon the exercise of stock options, Shares	47,539
Net loss and comprehensive loss	$ (26,773)
Ending Balance at Jun. 30, 2021	$ 0		$ 0
Ending Balance, Shares at Jun. 30, 2021	0		0
Ending Balance at Jun. 30, 2021	$ 51,298				$ 19		216,314		(165,035)
Ending Balance, Shares at Jun. 30, 2021					19,470,914
Beginning Balance at Mar. 31, 2021			$ 127,168
Beginning Balance, Shares at Mar. 31, 2021			202,009,981
Beginning Balance at Mar. 31, 2021	(144,409)				$ 0		5,144		(149,553)
Beginning Balance, Shares at Mar. 31, 2021					763,573
Proceeds from initial public offering, net of underwriters' discounts and commissions and issuance costs	71,997				$ 5		71,992
Proceeds from initial public offering, net of underwriters' discounts and commissions and issuance costs, Shares					5,333,334
Issuance of common stock upon exercise of warrants for cash	377						377
Issuance of common stock upon exercise of warrants for cash (in shares)					23,887
Issuance of common stock upon net exercise of warrants upon initial public offering	734						734
Issuance of common stock upon net exercise of warrants upon initial public offering (in shares)					37,628
Issuance of common stock upon exchange of Avenue warrant	1,763						1,763
Issuance of common stock upon exchange of Avenue warrant (in shares)					107,663
Conversion of redeemable convertible preferred stock to common stock upon initial public offering		$ 127,168		$ (127,168)		$ 13		$ 127,155
Conversion of redeemable convertible preferred stock to common stock upon initial public offering, Shares				(202,009,981)		12,605,800
Conversion of convertible notes into common stock at initial public offering	8,393				$ 1		8,392
Conversion of convertible notes into common stock at initial public offering (in shares)					559,585
Stock-based compensation expense	556						556
Issuance of common stock upon the exercise of stock options	201						201
Issuance of common stock upon the exercise of stock options, Shares					39,444
Net loss and comprehensive loss	(15,482)								(15,482)
Ending Balance at Jun. 30, 2021	$ 0		$ 0
Ending Balance, Shares at Jun. 30, 2021	0		0
Ending Balance at Jun. 30, 2021	$ 51,298				$ 19		$ 216,314		$ (165,035)
Ending Balance, Shares at Jun. 30, 2021					19,470,914

Condensed Consolidated Statem_3

Condensed Consolidated Statement of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) (Unaudited) $ in Millions	3 Months Ended
	Jun. 30, 2021USD ($)
Statement of Stockholders' Equity [Abstract]
Stock issuance cost	$ 2.4
Net underwiters discount and commission	$ 5.6

Condensed Consolidated Statem_4

Condensed Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (26,773)	$ (22,681)	$ (45,798)	$ (41,859)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	493	476	1,077	722
Stock-based compensation	1,049	2,783	3,641	794
Change in fair value of redeemable convertible preferred stock warrant liabilities	54	(80)	153	642
Change in Fair Value of Convertible Notes	839
Noncash interest	55
Amortization of debt discount	446		208
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(3,542)	(125)	1,447	(960)
Other assets	0	(187)	(187)	325
Accounts payable	1,070	607	1,498	1,424
Accrued liabilities	365	(113)	(1,222)	2,425
Net cash used in operating activities	(25,944)	(19,320)	(39,183)	(36,487)
Cash flows from investing activities:
Purchases of property and equipment	(116)	(818)	(1,782)	(1,523)
Net cash used in investing activities	(116)	(818)	(1,782)	(1,523)
Cash flows from financing activities:
Proceeds from initial public offering, net of issuance costs	71,997
Proceeds from Convertible Debt	7,500
Proceeds from exercise of redeemable convertible preferred stock warrants	197	18	479
Proceeds from issuance of common stock upon exercise of stock options	219	8	879	21
Proceeds from issuance of debt			9,701
Proceeds from Paycheck Protection Program loan			1,100
Repayment of Paycheck Protection Program loan			(1,100)
Net cash provided by financing activities	79,913	26	11,059	21
Net increase (decrease) in cash	53,853	(20,112)	(29,906)	(37,989)
Cash — Beginning of period	7,095	37,001	37,001	74,990
Cash — End of period	60,948	16,889	7,095	37,001
Supplemental disclosures of cash flow information:
Recognition of fair value of warrants issued in connection with issuance of debt			1,498
Accretion to redemption value on redeemable convertible preferred stock	129	256
Conversion of redeemable convertible preferred stock upon initial public offering	127,168
Issuance of common stock upon exchange / exercise of redeemable convertible preferred stock warrants upon initial public offering	2,677		395
Conversion of convertible notes into common stock upon initial public offering	8,393
Purchase of property and equipment included in accounts payable and accrued liabilities	$ 84	$ 145	$ 369	$ 114

Organization and Description of

Organization and Description of Business	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Impel Neuropharma, Inc. (“the Company”), is a biopharmaceutical company focused on the development and commercialization of transformative therapies for people suffering from diseases with high unmet medical needs, with an initial focus on the central nervous system, or CNS. The Company’s strategy is to pair its proprietary Precision Olfactory Delivery, or POD, upper nasal delivery technology with well-understood therapeutics or other therapeutics where rapid vascular absorption is preferred to drive therapeutic benefit, improve patient outcomes, reduce drug development risk and expand the commercial opportunity within its target diseases. The Company was incorporated under the laws of the State of Delaware on Initial Public Offering On April 22, 2021, the Company’s Registration Statement on Form S-1 Reverse Stock Split In April 2021, the Company’s board of directors and stockholders approved an amendment to the Company’s certificate of incorporation to effect a reverse split of shares of the Company’s common stock on an one-for-16.37332 Liquidity and Capital Resources The Company raised $72.0 million in net proceeds from its IPO in April 2021 and from the Company’s inception through June 30, 2021, it raised an aggregate of $214.5 million in gross cash proceeds from the IPO, sale and issuance of redeemable convertible preferred stock, convertible notes, debt and warrants. The Company had a cash and cash equivalents balance of $60.9 million as of June 30, 2021. Based upon the Company’s current operating plan, it estimates that its cash and cash equivalents as of June 30, 2021, are together sufficient for the Company to fund operating, investing, and financing cash flow needs for at least one year from the issuance date of these interim financial statements. On July 2, 2021, the Company entered into a loan and security agreement with Oxford Finance LLC (“Oxford”), as the collateral agent and a lender, and Silicon Valley Bank (“SVB”), as a lender to potentially borrow up to an aggregate principal amount of $50.0 million in a series of term loans (see Note 14). In the event of an FDA approval, the Company may be required to raise additional capital to meet working capital needs associated with commercialization. If sufficient funds on acceptable terms are not available when needed, the Company could be required to reduce operating expenses and delay, reduce the scope of, or eliminate one or more of its development programs or planned product launch plans. Failure to manage discretionary spending or raise additional financing, as needed, may adversely impact the Company’s ability to achieve its intended business objectives. The accompanying financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The accompanying financial statements do not reflect any adjustments relating to the recoverability and reclassifications of assets and liabilities that might be necessary if the Company is unable to continue as a going concern.	1. Organization and Description of Business Impel Neuropharma, Inc., or the Company, is a biopharmaceutical company focused on the development and commercialization of transformative therapies for people suffering from diseases with high unmet medical needs, with an initial focus on the central nervous system, or CNS. The Company’s strategy is to pair its proprietary Precision Olfactory Delivery, or POD, upper nasal delivery technology with well-understood therapeutics or other therapeutics where rapid vascular absorption is preferred to drive therapeutic benefit, improve patient outcomes, reduce drug development risk and expand the commercial opportunity within its target diseases. The Company was incorporated under the laws of the State of Delaware on Liquidity and Capital Resources The Company has incurred losses since its inception and had an accumulated deficit of $138.3 million as of December 31, 2020. The Company had a cash balance of $7.1 million as of December 31, 2020 and cash used in operations totaled $39.2 million for the year ended December 31, 2020. The Company believes that its cash as of December 31, 2020 will not be sufficient for the Company to continue as a going concern for at least one year from the issuance date of its financial statements. The Company believes that this raises substantial doubt about its ability to continue as a going concern. As a result, the Company will be required to raise additional capital. If sufficient funds on acceptable terms are not available when needed, the Company could be required to significantly reduce its operating expenses and delay, reduce the scope of or eliminate one or more of its development programs. Failure to manage discretionary spending or raise additional financing, as needed, may adversely impact the Company’s ability to achieve its intended business objectives. The accompanying financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business. The accompanying financial statements do not reflect any adjustments relating to the recoverability and reclassifications of assets and liabilities that might be necessary if the Company is unable to continue as a going concern.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or U.S. GAAP. The condensed consolidated financial statements include the operations of Impel Neuropharma, Inc., and its wholly owned Australian subsidiary. All intercompany balances and transactions have been eliminated upon consolidation. The condensed consolidated balance sheet as of June 30, 2021, the condensed consolidated statements of operations and comprehensive loss, changes in redeemable convertible preferred stock and stockholders’ equity (deficit) and cash flows for the three and six months ended June 30, 2021 and 2020 are unaudited. These unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s consolidated financial position as of June 30, 2021 and its results of operations and cash flows for the three and six months ended June 30, 2021 and 2020. The financial data and the other financial information contained in these notes to the condensed consolidated financial statements related to the three and six month periods are also unaudited. The results of operations for the three months and six months ended June 30, 2021 are not necessarily indicative of the results to be expected for the year ending December 31, 2021 or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2020 included herein was derived from the audited financial statements as of that date. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements included in the prospectus dated April 23, 2021 that forms a part of the Company’s Registration Statement on Form S-1 No. 333-254999), Reclassifications We have reclassified prior period financial statements to conform to the current period presentation. During the six months ended 2021, we reclassified certain amounts previously recorded as general and administrative expense to research and development expense. Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, management evaluates such estimates and assumptions for continued reasonableness. In particular, management makes estimates with respect to the fair values of common stock, redeemable convertible preferred stock warrant liabilities, stock-based compensation expense, convertible debt and income taxes. Appropriate adjustments, if any, to the estimates used are made prospectively based upon such periodic evaluation. Actual results could differ from those estimates. Segments The Company’s chief operating decision maker is its Chief Executive Officer. The Chief Executive Officer reviews financial information on an aggregate basis for the purposes of evaluating financial performance and allocating the Company’s resources. Accordingly, the Company has determined that it operates in one segment. Cash The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. At June 30, 2021 and December 31, 2020, cash consisted of cash in bank deposits held at financial institutions. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash. The Company’s cash is deposited with high credit quality financial institutions. At times such deposits may be in excess of the Federal Depository Insurance Corporation insured limits. Fair Value Measurement Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; Level 3— Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the accompanying consolidated balance sheets for cash, other current assets, accounts payable, and accrued liabilities approximate their fair values, due to their short-term nature. Convertible Notes In March 2021, the Company issued convertible promissory notes to various investors for an aggregate amount of $7.5 million. As permitted under Accounting Standards Codification (“ASC”) 825, Financial Instruments (“ASC 825”), the Company has elected the fair value option for recognition of the convertible notes. The Company elected the fair value option to allow the Company to eliminate the burden of complying with the requirements for derivative accounting. Under the fair value option, the convertible notes are remeasured at fair value in each reporting period until their conversion in April 2021, with changes in the fair value recognized in the Company’s condensed consolidated statement of operations as other (expense) income, net. Accrued interest on the convertible notes is recorded in other (expense), net. Deferred Offering Costs The Company incurred offering costs consisting of legal, accounting and other fees and costs directly attributable to the Company’s IPO. As of June 30, 2021, $2.4 million of deferred offering costs were charged to additional paid-in Redeemable Convertible Preferred Stock Warrant Liabilities Freestanding warrants to purchase shares of the Company’s redeemable convertible preferred stock are accounted for as liabilities at fair value through the date of exercise, because the shares underlying the warrants contain contingent redemption features outside the control of the Company. Warrants classified as liabilities are recorded on the Company’s condensed consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value each subsequent reporting period, with the changes in fair value recognized as a component of other (expense) income, net in the accompanying condensed consolidated statements of operations. The Company adjusted the liability for the final change in the fair value of these warrants immediately preceding their automatic exercise in connection with the IPO. Upon exercise, the corresponding liability was reclassified to additional paid-in Research and Development Research and development costs are expensed as incurred and consist primarily of salaries, benefits and other staff-related costs, including associated stock-based compensation, laboratory supplies, nonclinical and clinical studies and trials and related clinical manufacturing costs, costs related to manufacturing preparation, fees paid to other entities that conduct certain research and development activities on the Company’s behalf. Non-refundable Advance Payments for Research and Development Services and Accruals As part of the process of preparing its condensed consolidated financial statements, the Company is required to estimate its expenses resulting from its obligation under contracts with vendors and consultants and clinical site agreements in connection with its research and development efforts. The financial terms of these contracts are subject to negotiations which vary contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate research and development expenses in its condensed consolidated financial statements by matching those expenses with the period in which services and efforts are expended. The Company accounts for these expenses according to the progress of its research and development efforts. The Company determines advance payments for research and development services and accrual estimates through discussion with applicable personnel and outside service providers as to the progress of clinical trials, or other services completed. The Company adjusts its rate of research and development expense recognition if actual results differ from its estimates. The Company makes estimates of its advance payments and accrued expenses as of each balance sheet date in its condensed consolidated financial statements based on facts and circumstances known at that time. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of status and timing of services performed relative to the actual status and timing of services performed may vary and may result in the Company reporting amounts that are too high or too low for any particular period. Through June 30, 2021, there had been no material adjustments to the Company’s prior period estimates of advance payments and accruals for research and development expenses. The Company’s research and development advance payments and accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors. Stock-Based Compensation The Company recognizes stock-based compensation expense for stock options and restricted stock unit awards on a straight-line basis over the requisite service period. The Company’s stock-based compensation costs are based upon the grant date fair value of options estimated using the Black-Scholes-Merton option pricing model. This model utilizes as inputs the estimated fair value of the underlying common stock at the measurement date, the estimated term of the stock options (weighted-average period of time that the options granted are expected to be outstanding), risk-free interest rates, expected dividends, and the expected volatility of the Company’s common stock. The Company has elected to recognize forfeitures of share-based payment awards as they occur. The Company recognizes stock-based compensation expense for stock options granted to non-employees Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company. Comprehensive Loss Comprehensive loss represents the change in the Company’s stockholders’ equity (deficit) from all sources other than investments by or distributions to stockholders. The Company has no items of other comprehensive loss; as such, net loss equals comprehensive loss. Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2016-02, Leases Leases right-of-use No. 2020-05, Revenue from Contracts with Customers (Topic 606) and Leases (Topic 842): Effective Dates for Certain Entities, non-public right-of-use Recently Adopted Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) 815-40): ASU 2020-06, ASU 2020-06 removes ASU 2020-06 is	2. Summary of Significant Accounting Policies Basis of Presentation and Consolidation The accompanying consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or U.S. GAAP. The consolidated financial statements include the operations of Impel Neuropharma, Inc., and its wholly owned Australian subsidiary. All intercompany balances and transactions have been eliminated upon consolidation. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, management evaluates such estimates and assumptions for continued reasonableness. In particular, management makes estimates with respect to the fair values of common stock, redeemable convertible preferred stock warrant liabilities, stock-based compensation expense, and income taxes. Appropriate adjustments, if any, to the estimates used are made prospectively based upon such periodic evaluation. Actual results could differ from those estimates. Segments The Company’s chief operating decision maker is its Chief Executive Officer. The Chief Executive Officer reviews financial information on an aggregate basis for the purposes of evaluating financial performance and allocating the Company’s resources. Accordingly, the Company has determined that it operates in one segment. Cash The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. At December 31, 2019 and 2020, cash consisted of cash in bank deposits held at financial institutions. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash. The Company’s cash is deposited with high credit quality financial institutions. At times such deposits may be in excess of the Federal Depository Insurance Corporation insured limits. Other Assets The Company generated $134,000 and $15,000 of fully refundable research and development credits in 2019 and 2020, respectively, based on 43.5% of qualified research and development expenditures of its Australian subsidiary. Amounts due are recorded as an offset to research and development expense in the accompanying consolidated statements of operations. The amount receivable of $39,000 as of December 31, 2019 and $57,000 as of December 31, 2020 is included in prepaid expenses and other current assets in the accompanying consolidated balance sheets. Property and Equipment, Net Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the depreciable assets, ranging from three to four years. Property and equipment are primarily comprised of laboratory and platform equipment used to support research and development activities. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is reflected in the statement of operations in the year of disposition. Additions and improvements that increase the value or extend the life of an asset are capitalized. Repairs and maintenance costs are expensed as incurred. Leasehold improvements are amortized over the remaining term of the lease or the asset’s useful life, whichever is shorter. Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. The recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset or asset group to the estimated undiscounted future cash flows expected to be generated by the asset or asset group. If the carrying amount of an asset or asset group exceeds its estimated undiscounted future cash flows, an impairment charge is recognized as the amount by which the carrying amount of the asset exceeds the estimated discounted future cash flows of the asset or asset group. There have been no such impairments of long-lived assets for any of the periods presented. Fair Value Measurement Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; Level 3— Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the accompanying consolidated balance sheets for cash, other current assets, accounts payable, and accrued liabilities approximate their fair values, due to their short-term nature. Redeemable Convertible Preferred Stock Warrant Liabilities Freestanding warrants to purchase shares of the Company’s redeemable convertible preferred stock are accounted for as liabilities at fair value, because the shares underlying the warrants contain contingent redemption features outside the control of the Company. Warrants classified as liabilities are recorded on the Company’s consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value on each subsequent reporting period, with the changes in fair value recognized as a component of other expense, net in the accompanying consolidated statements of operations. The Company will continue to adjust the liability for changes in the fair value of these warrants until the earlier of the exercise of the warrants, the expiration of the warrants, or until such time as the warrants are no longer considered liability instruments. Leases The Company leases office space and laboratory facilities under non-cancelable incentives or allowances, these terms are applied in the determination of straight-line rent expense over the lease period. Stock-Based Compensation The Company recognizes stock-based compensation expense for stock options and restricted stock unit awards on a straight-line basis over the requisite service period. The Company’s stock-based compensation costs are based upon the grant date fair value of options estimated using the Black-Scholes-Merton option pricing model. This model utilizes as inputs the estimated fair value of the underlying common stock at the measurement date, the estimated term of the stock options (weighted-average period of time that the options granted are expected to be outstanding), risk-free interest rates, expected dividends, and the expected volatility of the Company’s common stock. The Company has elected to recognize forfeitures of share-based payment awards as they occur. The Company recognizes stock-based compensation expense for stock options granted to nonemployees based on the estimated fair value of the award as it is more readily measurable than the fair value of the services received. Income Taxes Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts or existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period of enactment. The Company records a valuation allowance to reduce deferred tax assets to an amount for which realization is more likely than not. The Company recognizes the tax benefit from an uncertain tax position if it is more likely than not that the tax position will be sustained upon examination by the tax authorities, based on the merits of the position. The Company does not believe any uncertain tax positions currently pending will have a material adverse effect on its consolidated financial statements nor does the Company expect any material change in its position in the next 12 months. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits. Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company. Comprehensive Loss Comprehensive loss represents the change in the Company’s stockholders’ deficit from all sources other than investments by or distributions to stockholders. The Company has no items of other comprehensive loss; as such, net loss equals comprehensive loss. Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases Leases right-of-use 2020-05, Revenue from Contracts with Customers (Topic 606) and Leases (Topic 842): Effective Dates for Certain Entities, non-public right-of-use Recently Adopted Pronouncements In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement 2018-13,

Fair Value Measurements

Fair Value Measurements	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The following table summarizes the fair value of the Company’s financial liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): December 31, 2020 Level 1 Level 2 Level 3 Total Liabilities: Redeemable convertible preferred stock warrant liabilities $ – $ – $ 2,622 $ 2,622 Total financial liabilities $ – $ – $ 2,622 $ 2,622 There were no financial liabilities as of June 30, 2021 that were measured at fair value. The following table summarizes the change in the fair value of the redeemable convertible preferred stock warrant liabilities for the six months ended June 30, 2021 (in thousands): Beginning balance as of December 31, 2020 2,622 Losses from changes in fair value 55 Settlement upon IPO (2,677 ) Ending balance as of June 30, 2021 $ – The following table summarizes the change in the fair value of the convertible not e Beginning balance as of December 31, 2020 $ – Issuance of convertible notes 7,500 Interest 54 Losses from changes in fair value 839 Conversion upon IPO (8,393 ) Ending balance as of June 30, 2021 $ – Fair values of the Company’s redeemable convertible preferred stock warrant liabilities and convertible notes are based on significant inputs not observed in the market, and thus represent a Level 3 measurement. Refer to Note 6 and Note 7 for the valuation techniques and assumptions used in estimating the fair value of the convertible notes and warrants, respectively.	3. Fair Value Measurements The following table summarizes the fair value of the Company’s financial liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): December 31, 2019 Level 1 Level 2 Level 3 Total Liabilities: Redeemable convertible preferred stock warrant liabilities $ – $ – $ 1,366 $ 1,366 Total financial liabilities $ – $ – $ 1,366 $ 1,366 December 31, 2020 Level 1 Level 2 Level 3 Total Liabilities: Redeemable convertible preferred stock warrant liabilities $ – $ – $ 2,622 $ 2,622 Total financial liabilities $ – $ – $ 2,622 $ 2,622 The following table summarizes the change in the fair value of the redeemable convertible preferred stock warrant liabilities for the years ended December 31, 2019 and 2020 (in thousands): December 31, 2019 2020 Beginning balance $ 724 $ 1,366 Losses from changes in fair value 642 153 Exercise of warrants – (395 ) Issuance of warrants – 1,498 Ending balance $ 1,366 $ 2,622 Fair values of the Company’s redeemable convertible preferred stock warrant liabilities are based on significant inputs not observed in the market, and thus represent a Level 3 measurement. Refer to Note 7 for the valuation techniques and assumptions used in estimating the fair value of the warrants.

Balance Sheet Components

Balance Sheet Components	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	4. Balance Sheet Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): June 30, December 31, Refundable clinical deposits $ 337 $ 672 Tax refund receivable 25 229 Prepaid insurance 3,050 47 Other prepaids and current assets 1,207 129 Total prepaid expenses and other current assets $ 4,619 $ 1,077 Accrued Liabilities Accrued liabilities consisted of the following (in thousands): June 30, December 31, Accrued professional services $ 1,340 $ 192 Accrued compensation 1,986 2,393 Accrued other liabilities 214 333 Accrued construction in progress 6 255 Total accrued liabilities $ 3,546 $ 3,173	4. Balance Sheet Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2019 2020 Refundable clinical deposits $ 1,891 $ 672 Tax refund receivable 201 229 Refundable security deposit 187 – Prepaid insurance 61 47 Other prepaids and current assets 184 129 Total prepaid expenses and other current assets $ 2,524 $ 1,077 Property and Equipment, Net The cost and accumulated depreciation and amortization of property and equipment were as follows (in thousands): December 31, 2019 2020 Laboratory and platform equipment $ 3,500 $ 4,613 Furniture and office equipment 100 100 Leasehold improvements 198 198 Construction in progress 683 1,607 Total property and equipment, gross 4,481 6,518 Less: accumulated depreciation and amortization (1,741 ) (2,818 ) Total property and equipment, net $ 2,740 $ 3,700 Depreciation and amortization expense totaled $722,000 and $1.1 million for the years ended December 31, 2019 and 2020, respectively. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): December 31, 2019 2020 Accrued professional services $ 2,187 $ 192 Accrued compensation 1,864 2,393 Accrued other liabilities 180 333 Accrued construction in progress – 255 Total accrued liabilities $ 4,231 $ 3,173

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	5. Commitments and Contingencies Operating Leases The Company leases office and laboratory space in Seattle, Washington. In September 2017, the Company entered into a non-cancelable Rent expense for the three months and six months ended June 30, 2021 was $175,000 and $349,000, respectively and for the three and six months ended June 30, 2020 was $188,000 and $344,000 respectively. Legal Proceedings From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made and that such expenditures can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount. Indemnifications In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company intends to enter into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance coverage that reduces its exposure and enables the Company to recover a portion of any future amounts paid. The Company believes the estimated fair value of these indemnification agreements in excess of applicable insurance coverage is minimal. COVID-19 In March 2020, the COVID-19 COVID-19	5. Commitments and Contingencies Operating Leases The Company leases office and laboratory space in Seattle, Washington. In September 2017, the Company entered into a non-cancelable Rent expense for the years ended December 31, 2019 and 2020 was $601,000 and $632,000, respectively. Legal Proceedings From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made and that such expenditures can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount. On November 19, 2019, a lawsuit was filed in the King County Superior Court for the State of Washington against the Company. The plaintiff, a former investment advisor, alleged that he was entitled to payment in connection with the Company’s December 2016 financing round. The lawsuit asserted, among other things, causes of action against the Company for breach of implied/quasi contract. Plaintiff sought monetary damages, attorneys’ fees, and equitable relief. On November 5, 2020, the Company and Plaintiff entered into a confidential settlement agreement that was not material. Indemnifications In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company intends to enter into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance coverage that reduces its exposure and enables the Company to recover a portion of any future amounts paid. The Company believes the estimated fair value of these indemnification agreements in excess of applicable insurance coverage is minimal. COVID-19 In March 2020, the COVID-19 COVID-19

Debt

Debt	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	6. Debt Term Loan On November 5, 2020 the Company entered into a debt and equity financing agreement with Avenue Venture Opportunities Fund, L.P., (“Avenue”). The agreement provides for a 36-month Payments for the term loan were initially interest only for the initial 12 months, extended to 24 months upon closing of our IPO, and can be extended to 36 months upon FDA approval of TRUDHESA. The term loan will amortize in equal payments of principal from the end of the interest only period to the expiration of the 36-month The Company’s obligations are secured by a security interest in substantially all of the Company’s assets, excluding the. Company’s intellectual property. The agreement contains customary representations, warranties and covenants, including covenants by the Company limiting additional indebtedness, liens, including on intellectual property, guaranties, mergers and consolidations, substantial asset sales, investments and loans, certain corporate changes, transactions with affiliates and fundamental changes. The agreement provides for events of default customary for term loans of this type, including but not limited to non-payment, The net proceeds from the issuance of the term loan were initially allocated to the warrants at an amount equal to their fair value of $1.5 million and the remainder to the term loan. The Company incurred financing costs of $299,000 which, together with the fair value of the warrants and the final payment, are recorded as a debt discount and are being amortized over the contractual term using the effective interest method. During the three and six months ended June 30, 2021, the Company incurred interest expense of $509,000 and $999,000, respectively and is classified as other (expense) income. The estimated fair value of the Avenue term loan, as of June 30, 2021 was $11.0 million, compared to the principal amount outstanding of $10.45 million. The estimated fair value was based on borrowing rates available to the Company for loans with similar terms and consideration of the Company’s credit risk, as such, the Company’s long-term debt was classified within Level 3 of the fair value hierarchy. The term loan consists of the following (in thousands): June 30, December 31, Face value of term loan $ 10,000 $ 10,000 Final payment 450 450 Unamortized debt discount associated with final payment, (1,593 ) (2,039 ) Total debt, net $ 8,857 $ 8,411 Less: short-term debt – 417 Long-term debt $ 8,857 $ 7,994 As described in Notes 1 and 14 of these financial statements, on July 2, 2021, the Company entered into a loan and security agreement (the “Agreement”) with Oxford and SVB (together with Oxford, the “Lenders”), to borrow up to an aggregate principal amount of $50.0 million in a series of term loans. Upon entering into the Agreement, the Company borrowed $20.0 million from the Lenders with approximately $10.8 million of such amount applied to the repayment of outstanding principal, interest and final payment fees owed under the debt and equity financing agreement with Avenue. As a result, the total debt, net has been classified on our balance sheet as Long-term debt – non-current Convertible Promissory Notes In March 2021, the Company issued unsecured convertible promissory notes to various investors for an aggregate amount of $7.5 million which were accounted for at fair value. The notes bore interest at a rate of 5.0% per annum and mature on the earlier of (a) December 31, 2021 and (b) a change of control. The notes were automatically converted into shares of the Company’s common stock upon the closing of the IPO. The agreement contained customary representations, warranties and covenants, including covenants by the Company limiting additional indebtedness, liens, including on intellectual property, guaranties, mergers and consolidations, substantial asset sales, investments and loans, certain corporate changes, transactions with affiliates and fundamental changes. The agreement provided for events of default customary for term loans of this type, including but not limited to non-payment, On March 31, 2021, the notes were remeasured to their settlement amount at the IPO date excluding accrued interest due to the proximity of the settlement date to the end of the reporting period. The loss on the increase in fair value on the convertible notes totaled $839,000 from their issuance through June 30, 2021 and is classified as other (expense) income, net in the accompanying condensed consolidated statements of operations. For the three and six months ended June 30, 2021, interest expense incurred in connection with the convertible promissory notes was $27,000 and $54,000, respectively and is classified as other (expense) income. The carrying value of the convertible notes of $8.4 million immediately prior to the Company’s IPO subsequently converted into 559,585 shares of common stock upon completion of the IPO.	6. Debt Payroll Protection Program In April 2020, the Company borrowed $1.1 million from the U.S. Small Business Administration Payroll Protection Program, or PPP, as provided by the Coronavirus Aid, Relief, and Economic Security Act. The PPP loans are intended to assist companies impacted by the COVID-19 Term Loan On November 5, 2020 the Company entered into a debt and equity financing agreement with Avenue Venture Opportunities Fund, L.P., or Avenue. The agreement provides for a 36-month Under the agreement, Avenue also has the right to invest up to $10.0 million in a private placement concurrent with an IPO (at the IPO price) or special purpose acquisition company, or SPAC, transaction (at the effective price per share), in each case, subject to mutual agreement and Avenue investment committee approval. Payments for the term loan are interest only for the initial 12 months and can be extended to (i) 24 months upon achieving a qualified IPO with gross proceeds of at least $75.0 million or (ii) 36 months upon achieving the first interest only period extension and FDA approval of TRUDHESA. The term loan will amortize in equal payments of principal from the end of the interest only period to the expiration of the 36-month the purchase of shares of 1,762,810 shares of Series D redeemable convertible preferred stock, as disclosed in Note 7. Avenue is eligible to receive additional warrants upon the draw down of the remaining $10.0 million under the agreement. The Company’s obligations are secured by a security interest in substantially all of the Company’s assets. The agreement contains customary representations, warranties and covenants, including covenants by the Company limiting additional indebtedness, liens, including on intellectual property, guaranties, mergers and consolidations, substantial asset sales, investments and loans, certain corporate changes, transactions with affiliates and fundamental changes. The agreement provides for events of default customary for term loans of this type, including but not limited to non-payment, The net proceeds from the issuance of the term loan were initially allocated to the warrants at an amount equal to their fair value of $1.5 million and the remainder to the term loan. The Company incurred financing costs of $299,000 which, together with the fair value of the warrants and the final payment, are recorded as a debt discount and are being amortized over the contractual term using the effective interest method. During the year ended December 31, 2020, the Company recorded interest expense of $303,000. The term loan consists of the following (in thousands): December 31, Face value of term loan $ 10,000 Final payment 450 Unamortized debt discount associated with final payment, issuance date warrant fair value, and financing costs (2,039 ) Total debt, net 8,411 Less: short-term debt 417 Long-term debt $ 7,994

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock Warrant Liabilities	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Warrants and Rights Note Disclosure [Abstract]
Redeemable Convertible Preferred Stock Warrant Liabilities	7. Redeemable Convertible Preferred Stock Warrant Liabilities The key terms of the redeemable convertible preferred stock warrant liabilities as of December 31, 2020 are summarized in the following table: Number of shares as of Exercise Expiration Exercisable into: June 30, December 31, Series A-2 – 862,471 $ 0.4996 September 30, 2021 Series C-1 – 1,124,877 0.5289 November 16, 2021 Series D redeemable convertible preferred stock – 1,762,810 0.7091 October 31, 2021 Total – 3,750,158 The fair value of the warrants was determined using an option pricing model. Under this model, the estimated equity value of the Company as of the measurement date was allocated to various classes of financial instruments (such as common and redeemable convertible preferred stock and warrants to purchase redeemable convertible preferred stock) based on their rights and preferences in an assumed liquidity scenario, which was estimated to occur in two years. Other assumptions used prior to the IPO included stock volatility ranging from 46.4% to 103.0% and risk-free interest rates ranging from 0.04% to 0.24% during the three months ended March 31, 2021. In April 2021, upon completion of the IPO, the Series A-2 C-1	7. Redeemable Convertible Preferred Stock Warrant Liabilities The key terms of the outstanding redeemable convertible preferred stock warrant liabilities as of December 31, 2019 are summarized in the following table: Number of shares Exercise Expiration Exercisable into: 2019 2020 Series A-2 1,248,551 862,471 $ 0.4996 March 31, 2021 Series B redeemable convertible preferred stock 378,111 – 0.8737 September 3, 2020 Series C-1 1,124,877 1,124,877 0.5289 November 16, 2021 Series D redeemable convertible preferred stock – 1,762,810 0.7091 October 31, 2030 Total 2,751,539 3,750,158 During 2020, warrants for the purchase of 296,008 shares of Series A-2 A-2 September 30, 2021 The fair value of the warrants was determined using an option pricing model. Under this model, the estimated equity value of the Company as of the measurement date is allocated to various classes of financial instruments (such as common and redeemable convertible preferred stock and warrants to purchase redeemable convertible preferred stock) based on their rights and preferences in an assumed liquidity scenario, which was estimated

Redeemable Convertible Prefer_2

Redeemable Convertible Preferred Stock	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Temporary Equity Disclosure [Abstract]
Redeemable Convertible Preferred Stock	8. Redeemable Convertible Preferred Stock Redeemable convertible preferred stock consisted of the following (in thousands, except share amounts) as of December 31, 2020: Redeemable Convertible Preferred Stock Shares Shares Issued Carrying Aggregate Series A-1 746,426 746,426 $ 238 $ 305 Series A-2 9,869,218 8,805,587 4,147 4,399 Series B 3,968,775 3,968,775 3,980 4,421 Series C-1 43,278,699 42,153,822 20,975 22,297 Series C-2 26,537,826 26,537,826 15,390 15,000 Series C-3 24,605,790 24,605,790 14,973 15,000 Series D 95,191,755 95,191,755 67,336 67,500 Total 204,198,489 202,009,981 $ 127,039 $ 128,922 Classification The Company classified its redeemable convertible preferred stock as mezzanine equity on the condensed consolidated balance sheets as the shares were contingently redeemable with passage of time or upon deemed liquidation events, such as a change in control. As only the passage of time is required for Series B, C-1, C-2, C-3, A-1 A-2, paid-in In April 2021, immediately prior to the completion of the IPO (see Note 1), all outstanding shares of redeemable convertible preferred stock were automatically converted into 12,605,800 shares of common stock. Upon conversion into common stock, the carrying value of the redeemable convertible preferred stock of $127.2 million was reclassified to equity.	8. Redeemable Convertible Preferred Stock Redeemable convertible preferred stock as of December 31, 2019 consisted of the following (in thousands, except share amounts): Redeemable Convertible Preferred Stock Shares Shares Issued Carrying Aggregate Series A-1 746,426 746,426 $ 238 $ 305 Series A-2 9,869,218 8,509,579 3,876 4,251 Series B 3,968,775 3,590,664 3,234 4,000 Series C-1 43,278,699 42,153,822 20,648 22,297 Series C-2 26,537,826 26,537,826 15,390 15,000 Series C-3 24,605,790 24,605,790 14,965 15,000 Series D 95,191,755 95,191,755 67,296 67,500 Total 204,198,489 201,335,862 $ 125,647 $ 128,353 Redeemable convertible preferred stock as of December 31, 2020 consisted of the following (in thousands, except share amounts): Redeemable Convertible Preferred Stock Shares Shares Issued Carrying Aggregate Series A-1 746,426 746,426 $ 238 $ 305 Series A-2 9,869,218 8,805,587 4,147 4,399 Series B 3,968,775 3,968,775 3,980 4,421 Series C-1 43,278,699 42,153,822 20,975 22,297 Series C-2 26,537,826 26,537,826 15,390 15,000 Series C-3 24,605,790 24,605,790 14,973 15,000 Series D 95,191,755 95,191,755 67,336 67,500 Total 204,198,489 202,009,981 $ 127,039 $ 128,922 The holders of redeemable convertible preferred stock have various rights and preferences as follows: Conversion Rights Each share of redeemable convertible preferred stock is convertible into such number of fully paid shares of common stock as is determined by dividing the original issue price by the conversion price in effect at the time of conversion. As of December 31, 2019 and 2020, each share of Series A-1, A-2, C-1, C-2, C-3, Conversion can occur at any time at the option of each holder. In addition, all shares of preferred stock will convert automatically upon (1) the closing of a firm-commitment underwritten public offering, at a per share price of at least $1.0636, resulting in at least $50.0 million in net proceeds, or a Qualified Public Offering, or (2) by vote or written consent of the holders of a majority of the then outstanding shares of Series B, C-1, C-2, C-3 Dividends The holders of shares of Series A-1, A-2, C-1, C-2, C-3 non-cumulative, as-converted Liquidation In the event of any voluntary or involuntary liquidation, dissolution, or winding up of the Company, the holders of Series C-1, C-2, C-3 C-1, C-2, C-3 A-1 A-2 A-1 A-2) and similar events. Upon completion of the payment of the full liquidation preference of preferred stock, the remaining assets of the Company, if any, will be distributed among the holders of preferred stock and common stock, pro rata on an as-converted Redemption Series B, C-1, C-2 C-3 as-converted C-1, C-2 C-3 Voting Rights Each share of preferred stock has a number of votes equal to the number of shares of common stock into which it is convertible. The holders of Series A-1 A-2 C-1, C-2 C-3 as-converted Classification The Company has classified its redeemable convertible preferred stock as mezzanine equity on the consolidated balance sheets as the shares are contingently redeemable with passage of time or upon deemed liquidation events, such as a change in control. As only the passage of time is required for Series B, C-1, C-2, C-3, A-1 A-2, paid-in

Common Stock

Common Stock	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Equity [Abstract]
Common Stock	9. Common Stock Each share of common stock has the right to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. No cash dividends have been declared by the board of directors from inception. The Company has reserved the following shares of common stock for issuance, on an as-converted June 30, December 31, Stock incentive plans 5,219,804 2,786,345 Redeemable convertible preferred stock – 12,605,800 Convertible notes – – Redeemable convertible preferred stock warrants – 229,034 Total 5,219,804 15,621,179	9. Common Stock Each share of common stock has the right to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. No cash dividends have been declared by the board of directors from inception. The Company has reserved the following shares of common stock for issuance, on an as-converted December 31, 2019 2020 Stock incentive plans 2,585,294 2,786,345 Redeemable convertible preferred stock 12,539,109 12,605,800 Redeemable convertible preferred stock warrants 193,583 229,034 Total 15,317,986 15,621,179

Stock Incentive Plan

Stock Incentive Plan	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Incentive Plan	10. Stock Incentive Plan 2021 Equity Incentive Plan The Company adopted its 2021 Stock Incentive Plan, or the 2021 Plan, and the Employee Stock Purchase Plan, or the ESPP, which became effective on the date immediately prior to the date of effectiveness of the IPO. The 2021 Plan serves as the successor to its 2018 Equity Incentive Plan (the “2018 Plan”). The 2021 Plan authorizes the award of stock options, RSUs, restricted stock awards, stock bonus awards, stock appreciation rights, performance awards, and cash awards. The Company initially reserved 2,205,000 shares of its common stock for the 2021 Plan, plus any reserved shares not issued or subject to outstanding grants under the 2018 Plan on the effective date of the 2021 Plan, for issuance pursuant to awards granted under its 2021 Plan. The total number of shares reserved for issuance under the 2021 Plan upon its effective date is 2,272,613 shares The number of Shares available for issuance under the 2021 Plan will increase automatically on January 1 of each of 2022 through 2031 by the lesser of (a) 5% of the total number of outstanding shares of all classes of its common stock on each December 31 st 2008 Plan In September 2008, the Company’s board of directors adopted the 2008 Stock Incentive Plan, or the 2008 Plan, which provides for the granting of incentive stock options, nonqualified stock options, and restricted stock awards to its employees, directors and consultants. Options granted or shares issued under the 2008 Plan that were outstanding on the date the 2018 Equity Incentive Plan, or the 2018 Plan, became effective will remain subject to the terms of the 2008 Plan. The 2008 Plan terminated in 2018 as it reached its ten-year 2018 Plan In November 2018, the Company’s board of directors adopted the 2018 Equity Incentive Plan. The 2018 Plan provides for the granting of incentive stock options, nonqualified stock options, restricted stock units, and other forms of stock awards to its employees, directors and consultants. Under the 2018 Plan, the Company initially reserved 753,645 shares of common stock for issuance. In addition, any authorized shares not issued or subject to outstanding grants under the 2008 Plan and any shares subject to outstanding stock options that are cancelled without being exercised or expire under the 2008 Plan were added to the shares authorized and reserved for issuance under the 2018 Plan. In connection with the Board of Directors approval of the 2021 Plan, all remaining shares available for future award under the 2018 Plan were transferred to the 2021 Plan. At June 30, 2021 and December 31, 2020, options to purchase 2,034,734 and 1,807,101 shares, respectively, under 2018 Plan remained outstanding. Stock Option Activity A summary of the Company’s stock option activity under its stock option plans was as follows (in thousands, except share and per share data and years): Options Outstanding Shares Number of Weighted Remaining Aggregate Balance—December 31, 2020 344,456 2,441,889 $ 5.17 8.02 $ 14,844 Authorized 2,205,000 – Granted (408,464 ) 408,464 12.39 Exercised – (47,539 ) 4.61 Cancelled 32,029 (32,059 ) 4.86 Balance—June 30, 2021 2,173,021 2,770,785 $ 6.25 7.87 $ 8,660 Exercisable—June 30, 2021 – 1,316,271 $ 4.00 6.88 $ 6,388 In May 2020, the Company’s board of directors increased the pool of stock options available for future grant by 596,414 shares and appointed an existing member of the board of directors as the Company’s Chief Executive Officer. In connection with this change, the Company granted 715,358 stock options to its Chief Executive Officer at an exercise price of $7.86 per share that will vest ratably over 48 months. Vesting of the Chief Executive Officer’s options accelerate upon a termination without cause. In the second quarter of 2020, the Company recognized $2.1 million of expense related to a modification upon the acceleration of the former Chief Executive Officer’s outstanding options upon his departure from the Company. The total intrinsic value of options exercised was $202,000 and $26,000 during the six months ended June 30, 2021 and 2020, respectively. The intrinsic value is the difference between the estimated fair value of the Company’s common stock at the time of exercise, as determined by the board of directors, and the exercise price of the stock option. The total fair value of options that vested during the six months ended June 30, 2021 and 2020 was $1.3 million and $0.9 million, respectively. The grant date fair value of options granted during the six months ended June 30, 2021 and 2020 was $2.9 million and $3.8 million, respectively. The weighted-average grant date fair value of employee options granted during the six months ended June 30, 2021 and 2020 was $7.22 and $4.42 per share, respectively. Stock-Based Compensation Expense Stock-based compensation expense recognized was as follows (in thousands): Three Months Six Months Ended 2021 2020 2021 2020 General and administrative $ 437 $ 2,360 $ 811 $ 2,539 Research and development 119 125 238 244 Total stock-based compensation expense $ 556 $ 2,485 $ 1,049 $ 2,783 As of June 30, 2021, there was $5.0 million of total unrecognized compensation cost related to unvested options that are expected to vest. The cost is expected to be recognized over a weighted-average period of 2.8 years. In determining the fair value of the stock options granted, the Company uses the Black-Scholes-Merton option-pricing model and assumptions discussed below. Each of these inputs is subjective. Fair Value of Common Stock— Expected Term mid-point Expected Volatility Risk-Free Interest Rate Expected Dividend The fair value of stock option awards granted to employees was estimated at the date of grant using a Black-Scholes-Merton option pricing model with the following assumptions: Three Months Ended Six Months Ended 2021 2020 2021 2020 Expected term (in years) 6.1 6.1 6.1 6.1 Expected volatility 59.2-85.5% 56.4-59.7% 59.2-85.5% 56.4-59.7% Risk-free interest rate 0.79-0.86% 0.36-0.41% 0.42-0.92% 0.36-1.55% Expected dividends – – – –	10. Stock Incentive Plan 2008 Plan In September 2008, the Company’s board of directors adopted the 2008 Stock Incentive Plan, or the 2008 Plan, which provides for the granting of incentive stock options, nonqualified stock options, and restricted stock awards to its employees, directors and consultants. Options granted or shares issued under the 2008 Plan that were outstanding on the date the 2018 Equity Incentive Plan, or the 2018 Plan, became effective will remain subject to the terms of the 2008 Plan. The 2008 Plan terminated in 2018 as it reached its ten-year 2018 Plan In November 2018, the Company’s board of directors adopted the 2018 Equity Incentive Plan. The 2018 Plan provides for the granting of incentive stock options, nonqualified stock options, restricted stock units, and other forms of stock awards to its employees, directors and consultants. The 2018 Plan is administered by the board of directors or a committee appointed by the board of directors, which determines the types of awards to be granted, including the number of shares subject to the awards, the exercise price and the vesting schedule. The exercise price of incentive stock options and nonqualified stock options will be no less than 100% of the fair value per share of the Company’s common stock on the date of grant. If an individual owns capital stock representing more than 10% of the voting shares and the grant is an incentive stock option, the price of each share will be at least 110% of the fair value on the date of grant. Options expire after 10 years (five years for incentive stock options granted to stockholders owning greater than 10% of the voting stock). The term and vesting periods for options granted under the 2018 Plan are determined by the Company’s board of directors or a committee appointed by the board of directors. Options granted generally vest over four years. Options must be exercised within a 10-year Stock Option Activity A summary of the Company’s stock option activity under its stock option plans was as follows (in thousands, except share and per share data and y e Options Outstanding Shares Number of Weighted- Remaining Aggregate Balance—December 31, 2019 250,464 2,334,830 $ 3.29 8.37 $ 11,441 Authorized 596,414 – – Granted (902,544 ) 902,544 $ 7.94 Exercised – (395,363 ) $ 2.23 Cancelled 400,122 (400,122 ) $ 3.35 Balance—December 31, 2020 344,456 2,441,889 $ 5.17 8.02 $ 14,844 Exercisable—December 31, 2020 958,319 $ 3.01 9.76 $ 8,101 In May 2020, the Company’s board of directors increased the pool of stock options available for future grant by 596,414 shares and appointed an existing member of the board of directors as the Company’s Chief Executive Officer. In connection with this change, the Company granted 715,358 stock options to its Chief Executive Officer at an exercise price of $7.86 per share that will vest ratably over 48 months. Vesting of the Chief Executive Officer’s options accelerate upon a termination without cause. The Company recognized $2.1 million of expense related to a modification upon the acceleration of the former Chief Executive Officer’s outstanding options upon his departure from the Company. The Company granted 276,843 stock options in total subsequent to the period end with an exercise price range of $11.47 to $13.76 per share. The total intrinsic value of options exercised was $94,000 and $3.7 million during the years ended December 31, 2019 and 2020, respectively. The intrinsic value is the difference between the estimated fair value of the Company’s common stock at the time of exercise, as determined by the board of directors, and the exercise price of the stock option. The total fair value of options that vested during the years ended December 31, 2019 and 2020 was $451,000 and $1.1 million, respectively. The grant date fair value of options granted during the years ended December 31, 2019 and 2020 was $3.1 million and $3.9 million, respectively. The weighted-average grant date fair value of employee options granted during the years ended December 31, 2019 and 2020 was $2.34 and $4.24 per share, respectively. Stock-Based Compensation Expense Stock-based compensation expense recognized was as follows (in thousands): Year Ended 2019 2020 Research and development $ 341 $ 488 General and administrative 453 3,153 Total stock-based compensation expense $ 794 $ 3,641 As of December 31, 2020, there was $5.3 million of total unrecognized compensation cost related to unvested options that are expected to vest. The cost is expected to be recognized over a weighted-average period of 3.0 years In determining the fair value of the stock options granted, the Company uses the Black-Scholes-Merton option-pricing model and assumptions discussed below. Each of these inputs is subjective. Fair Value of Common Stock— Expected Term mid-point Expected Volatility Risk-Free Interest Rate Expected Dividend The fair value of stock option awards granted to employees was estimated at the date of grant using a Black-Scholes-Merton option pricing model with the following assumptions: Year Ended December 31, 2019 2020 Expected term (in years) 6.1 6.1 Expected volatility 54.3% – 57.7% 56.4% – 60.9% Risk-free interest rate 1.62% – 2.44% 0.27% – 1.55% Expected dividends – –

Income Taxes

Income Taxes	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes To calculate the interim tax provision, at the end of each interim period the Company estimates the annual effective tax rate and applies that to its quarterly earnings from continuing operations. The effect of changes in the enacted tax laws or rates is recognized in the interim period in which the change occurs. The computation of the annual estimated effective tax rate at each interim period requires certain estimates and judgments including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in foreign jurisdictions, permanent differences between book and tax amounts, and the likelihood of recovering deferred tax assets generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, additional information is obtained, or the tax environment changes. The Company’s effective tax rate for the six months ended June 30, 2021 and 2020 differs from the U.S. statutory rate due to the U.S. valuation allowance and foreign income taxed at local statutory rates. During the three and six months ended June 30, 2021, the Company reported U.S. pre-tax	11. Income Taxes The components of loss before taxes were as follows (in thousands): Year Ended 2019 2020 Domestic $ (42,039 ) $ (45,801 ) Foreign 210 4 Total loss before provision for income tax $ (41,829 ) $ (45,797 ) The provision for income taxes consisted of the following (in thousands): Year Ended 2019 2020 Current: Federal $ – $ – State 1 1 Foreign 29 – Total current tax expense $ 30 $ 1 Reconciliation of income tax computed at federal statutory rates to the reported provision for income taxes was as follows (in thousands): Year Ended 2019 2020 Tax provision at U.S. statutory rate $ (8,784 ) $ (9,617 ) Permanent differences 321 695 Change in valuation allowance 9,609 9,374 Research and development credits (985 ) (849 ) Other (131 ) 398 Provision for income taxes $ 30 $ 1 Significant components of the Company’s deferred income taxes at December 31, 2019 and 2020 are shown below (in thousands): December 31, 2019 2020 Deferred tax assets: Net operating losses $ 17,199 $ 25,239 Research and development and other tax credits 3,533 4,740 Other 1,120 1,244 Gross deferred tax assets 21,852 31,223 Less valuation allowance (21,849 ) (31,223 ) Total deferred tax assets 3 – Deferred tax liabilities: Fixed assets (3 ) – Gross deferred tax liabilities (3 ) – Net deferred tax asset $ – $ – In accordance with the authoritative guidance for income taxes under ASC 740, a deferred tax asset or liability is recognized for the expected future tax consequences of temporary differences between the financial statement carrying amounts and tax bases of assets and liabilities. At December 31, 2020, the Company had federal net operating loss, or NOL, and research and development credit carryforwards of approximately $21.4 million and $6.5 million, respectively. These carryforwards begin to expire in 2028 and 2029, respectively. In addition, the Company has $98.7 million of post 2017 federal NOL carryforwards that carry forward indefinitely. Utilization of the post 2017 federal NOL carryforwards is limited to eighty-percent of taxable income generated in a given tax year. Under Sections 382 and 383 of the Internal Revenue Code of 1986 as amended, or IRC, the Company’s NOL and research and development credit carryforwards and other deferred tax assets may be limited or lost if cumulative changes in ownership exceeds 50% within any rolling three-year period. The Company has not completed an IRC Section 382/383 analysis regarding the limitation of NOL and credit carryforwards. If a change in ownership were to have occurred, the annual limitation may result in the expiration of NOL carryforwards and credits before utilization. If eliminated, the related asset would be removed from the deferred tax asset schedule with a corresponding reduction in the valuation allowance. In evaluating its valuation allowance, the Company considers all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial performance. Due to uncertainty with respect to ultimate realizability of deferred tax assets, the Company has provided a valuation allowance against the U.S. deferred tax assets. The valuation allowance increased by $9.6 million and $9.4 million during the years ended December 31, 2019 and 2020, respectively, primarily due to NOLs incurred. The following table presents a reconciliation of the changes in the unrecognized tax benefit (in thousands): Balance as of December 31, 2018 $ 892 Increases related to prior year tax positions 94 Increases related to current year tax positions 619 Balance as of December 31, 2019 1,605 Increases related to prior year tax positions 9 Increases related to current year tax positions 534 Balance as of December 31, 2020 $ 2,148 The Company does not anticipate the amount of unrecognized tax benefits to significantly change within the next 12 months. Due to the valuation allowance recorded against the Company’s deferred tax assets, none of the total unrecognized tax benefits as of December 31, 2019 and 2020, would reduce the effective tax rate if recognized. As of December 31, 2019 and 2020, there are no penalties or accrued interest recorded in the consolidated financial statements. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. The Company files tax returns with the U.S. federal, California state, and Australian tax authorities. The Company currently has no years under examinations by any jurisdiction; however, the Company is subject to income tax examinations by Federal, California and Australian tax authorities for years beginning in 2016, 2017, and 2016, respectively. Further, to the extent allowed by law, the taxing authorities may have the right to examine prior originating periods when NOLs and tax credits are being utilized in the current year. The Company has made the accounting policy election to recognize the impact of Global Intangible Low-Tax

Defined Contribution Plan

Defined Contribution Plan	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Defined Contribution Plan	12. Defined Contribution Plan The Company has a defined contribution retirement savings plan under Section 401(k) of the IRC. This plan allows eligible employees to defer a portion of their annual compensation on a pre-tax after-tax	12. Defined Contribution Plan The Company has a defined contribution retirement savings plan under Section 401(k) of the IRC. This plan allows eligible employees to defer a portion of their annual compensation on a pre-tax after-tax

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	13. Net Loss Per Share Attributable to Common Stockholders The following outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share attributable to common stockholders for the periods presented because their effect would have been anti-dilutive: Six Months Ended June 30, 2021 2020 Redeemable convertible preferred stock on an as-converted – 12,541,340 Redeemable convertible preferred stock warrants on an as-converted basis – 185,889 Convertible notes on an as-converted – – Stock options to purchase common stock 2,770,785 3,033,480 Total 2,770,785 15,760,709	13. Net Loss Per Share Attributable to Common Stockholders The following outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share attributable to common stockholders for the periods presented because their effect would have been anti-dilutive: Year Ended 2019 2020 Redeemable convertible preferred stock on an as-converted 12,539,109 12,605,800 Redeemable convertible preferred stock warrants on an as-converted 193,583 229,034 Stock options to purchase common stock 2,334,830 2,441,889 Total 15,067,522 15,276,723

Subsequent Events

Subsequent Events	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events For the three and six month periods ended June 30, 2021, the Company evaluated subsequent events through August 16, 2021, the date the interim condensed consolidated financial statements were issued. On July 2, 2021, the Company entered into the Agreement with Oxford, as the collateral agent and a lender, and SVB, as a lender, pursuant to which the Lenders have agreed to lend the Company up to an aggregate of $ 50.0 10.8 Under the terms of the Agreement, the Company may, at its sole discretion, borrow from the Lenders up to an additional $10.0 Under the terms of the Agreement, the Company may, at its sole discretion, borrow from the Lenders up to an additional $20.0 million (the “Term C Loan”) upon the achievement by the Company of net revenue for a trailing six (6) month period of at least $15,000,000, as determined by Oxford in its sole and absolute discretion (the “Term C Milestone Event”). The Company may draw the Term C Loan during the period commencing on the date of the occurrence of the Term C Milestone Event and ending on the earliest of (i) December 31, 2022 (ii) the sixtieth (60th) day following the occurrence of the Term C Milestone Event, and (iii) the occurrence of an event of default. The proceeds from the Term Loans under the Agreement may be used to satisfy the Company’s future working capital needs and to fund its general business requirements. The Company’s obligations under the Agreement are secured by all assets of the Company, other than its intellectual property. The Company has also agreed not to encumber its intellectual property assets, except as permitted by the Agreement. All of the Term Loans mature on July 1, 2026 (the “Maturity Date”) and will be interest-only through September 1, 2023, provided however, that following Company’s achievement of the Term C Milestone Event by not later than December 31, 2022, the Term Loans will be interest-only through September 1, 2024, followed by 35 equal monthly payments of principal and interest, provided, however, that following Company’s achievement of the Term C Milestone Event by no later than December 31, 2022, such number of months shall be automatically reduced to 23 consecutive months. The Term Loans will bear interest at a floating per annum rate equal to the greater of (i) 7.95% or (ii) the sum of (a) the greater of (1) the thirty (30) day U.S. LIBOR rate reported in the Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue or (2) 0.11%, plus (b) 7.84%. The Company will be required to make a final payment of 6.5% of the original principal amount of the Term Loans drawn, payable on the earlier of (i) the Maturity Date, (ii) the acceleration of any Term Loans, or (iii) the prepayment of the Term Loans (the “Final Payment”). The Company may prepay all, but not less than all, of the Term Loans upon 30 days’ advance written notice to Oxford, provided that the Company will be obligated to pay a prepayment fee equal to (i) 3.0% of the principal amount of the applicable Term Loan prepaid on or before the first anniversary of the applicable funding date, (ii) 2.0% of the principal amount of the applicable Term Loan prepaid between the first and second anniversary of the applicable funding date, and (iii) 1.0% of the principal amount of the applicable Term Loan prepaid thereafter, and prior to the Maturity Date (each, a “Prepayment Fee”). In connection with entering into the Agreement and borrowing the Term A Loan, the Company issued to the Lenders warrants exercisable for an aggregate of 71,522 shares of the Company’s common stock (the “Warrants”). The Warrants are exercisable in whole or in part, immediately, and have a per share exercise price of $8.389, which is the 10-trading 10-trading	14. Subsequent Events For the year ended December 31, 2020, the Company evaluated its consolidated financial statements for subsequent events through March 23, 2021, the date the consolidated financial statements were issued, and April 19, 2021, the date the revised financial statements were issued. The Company has concluded that no events or transactions have occurred that require adjustment to or disclosure in the accompanying financial statements, other than the following: a) In March 2021, the Company issued convertible promissory notes to various investors for an aggregate amount of $7.5 million. The notes bear interest at a rate of 5.0% per annum and mature on the earlier of (a) December 31, 2021 and (b) a change of control. The notes are (i) automatically convertible into shares of the Company’s common stock upon a Qualified Public Offering or a SPAC transaction at 90% of the price per share in such transactions, (ii) convertible at the holder’s option or upon a change of control into shares of Series D redeemable convertible preferred stock at the Series D original issuance price, and (iii) convertible at the holder’s option upon a new redeemable convertible preferred stock financing into shares of redeemable preferred stock issued in such financing at 90 b) In the first quarter of 2021, the Company granted 276,843 stock options at exercise prices ranging from $ 11.47 to $ c) In April 2021, the Company’s board of directors and stockholders approved an amendment to the Company’s certificate of incorporation to effect a reverse split of shares of the Company’s common stock on an one-for-16.37332

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or U.S. GAAP. The condensed consolidated financial statements include the operations of Impel Neuropharma, Inc., and its wholly owned Australian subsidiary. All intercompany balances and transactions have been eliminated upon consolidation. The condensed consolidated balance sheet as of June 30, 2021, the condensed consolidated statements of operations and comprehensive loss, changes in redeemable convertible preferred stock and stockholders’ equity (deficit) and cash flows for the three and six months ended June 30, 2021 and 2020 are unaudited. These unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s consolidated financial position as of June 30, 2021 and its results of operations and cash flows for the three and six months ended June 30, 2021 and 2020. The financial data and the other financial information contained in these notes to the condensed consolidated financial statements related to the three and six month periods are also unaudited. The results of operations for the three months and six months ended June 30, 2021 are not necessarily indicative of the results to be expected for the year ending December 31, 2021 or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2020 included herein was derived from the audited financial statements as of that date. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements included in the prospectus dated April 23, 2021 that forms a part of the Company’s Registration Statement on Form S-1 No. 333-254999),	Basis of Presentation and Consolidation The accompanying consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or U.S. GAAP. The consolidated financial statements include the operations of Impel Neuropharma, Inc., and its wholly owned Australian subsidiary. All intercompany balances and transactions have been eliminated upon consolidation.
Reclassifications	Reclassifications We have reclassified prior period financial statements to conform to the current period presentation. During the six months ended 2021, we reclassified certain amounts previously recorded as general and administrative expense to research and development expense.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, management evaluates such estimates and assumptions for continued reasonableness. In particular, management makes estimates with respect to the fair values of common stock, redeemable convertible preferred stock warrant liabilities, stock-based compensation expense, convertible debt and income taxes. Appropriate adjustments, if any, to the estimates used are made prospectively based upon such periodic evaluation. Actual results could differ from those estimates.	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, management evaluates such estimates and assumptions for continued reasonableness. In particular, management makes estimates with respect to the fair values of common stock, redeemable convertible preferred stock warrant liabilities, stock-based compensation expense, and income taxes. Appropriate adjustments, if any, to the estimates used are made prospectively based upon such periodic evaluation. Actual results could differ from those estimates.
Segments	Segments The Company’s chief operating decision maker is its Chief Executive Officer. The Chief Executive Officer reviews financial information on an aggregate basis for the purposes of evaluating financial performance and allocating the Company’s resources. Accordingly, the Company has determined that it operates in one segment.	Segments The Company’s chief operating decision maker is its Chief Executive Officer. The Chief Executive Officer reviews financial information on an aggregate basis for the purposes of evaluating financial performance and allocating the Company’s resources. Accordingly, the Company has determined that it operates in one segment.
Cash	Cash The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. At June 30, 2021 and December 31, 2020, cash consisted of cash in bank deposits held at financial institutions.	Cash The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. At December 31, 2019 and 2020, cash consisted of cash in bank deposits held at financial institutions.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash. The Company’s cash is deposited with high credit quality financial institutions. At times such deposits may be in excess of the Federal Depository Insurance Corporation insured limits.	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash. The Company’s cash is deposited with high credit quality financial institutions. At times such deposits may be in excess of the Federal Depository Insurance Corporation insured limits.
Other Assets		Other Assets The Company generated $134,000 and $15,000 of fully refundable research and development credits in 2019 and 2020, respectively, based on 43.5% of qualified research and development expenditures of its Australian subsidiary. Amounts due are recorded as an offset to research and development expense in the accompanying consolidated statements of operations. The amount receivable of $39,000 as of December 31, 2019 and $57,000 as of December 31, 2020 is included in prepaid expenses and other current assets in the accompanying consolidated balance sheets.
Property and Equipment, Net		Property and Equipment, Net Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the depreciable assets, ranging from three to four years. Property and equipment are primarily comprised of laboratory and platform equipment used to support research and development activities. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is reflected in the statement of operations in the year of disposition. Additions and improvements that increase the value or extend the life of an asset are capitalized. Repairs and maintenance costs are expensed as incurred. Leasehold improvements are amortized over the remaining term of the lease or the asset’s useful life, whichever is shorter.
Impairment of Long-Lived Assets		Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. The recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset or asset group to the estimated undiscounted future cash flows expected to be generated by the asset or asset group. If the carrying amount of an asset or asset group exceeds its estimated undiscounted future cash flows, an impairment charge is recognized as the amount by which the carrying amount of the asset exceeds the estimated discounted future cash flows of the asset or asset group. There have been no such impairments of long-lived assets for any of the periods presented.
Fair Value Measurement	Fair Value Measurement Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; Level 3— Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the accompanying consolidated balance sheets for cash, other current assets, accounts payable, and accrued liabilities approximate their fair values, due to their short-term nature.	Fair Value Measurement Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; Level 3— Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the accompanying consolidated balance sheets for cash, other current assets, accounts payable, and accrued liabilities approximate their fair values, due to their short-term nature.
Convertible Notes	Convertible Notes In March 2021, the Company issued convertible promissory notes to various investors for an aggregate amount of $7.5 million. As permitted under Accounting Standards Codification (“ASC”) 825, Financial Instruments (“ASC 825”), the Company has elected the fair value option for recognition of the convertible notes. The Company elected the fair value option to allow the Company to eliminate the burden of complying with the requirements for derivative accounting. Under the fair value option, the convertible notes are remeasured at fair value in each reporting period until their conversion in April 2021, with changes in the fair value recognized in the Company’s condensed consolidated statement of operations as other (expense) income, net. Accrued interest on the convertible notes is recorded in other (expense), net.
Deferred Offering Costs	Deferred Offering Costs The Company incurred offering costs consisting of legal, accounting and other fees and costs directly attributable to the Company’s IPO. As of June 30, 2021, $2.4 million of deferred offering costs were charged to additional paid-in
Redeemable Convertible Preferred Stock Warrant Liabilities	Redeemable Convertible Preferred Stock Warrant Liabilities Freestanding warrants to purchase shares of the Company’s redeemable convertible preferred stock are accounted for as liabilities at fair value through the date of exercise, because the shares underlying the warrants contain contingent redemption features outside the control of the Company. Warrants classified as liabilities are recorded on the Company’s condensed consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value each subsequent reporting period, with the changes in fair value recognized as a component of other (expense) income, net in the accompanying condensed consolidated statements of operations. The Company adjusted the liability for the final change in the fair value of these warrants immediately preceding their automatic exercise in connection with the IPO. Upon exercise, the corresponding liability was reclassified to additional paid-in	Redeemable Convertible Preferred Stock Warrant Liabilities Freestanding warrants to purchase shares of the Company’s redeemable convertible preferred stock are accounted for as liabilities at fair value, because the shares underlying the warrants contain contingent redemption features outside the control of the Company. Warrants classified as liabilities are recorded on the Company’s consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value on each subsequent reporting period, with the changes in fair value recognized as a component of other expense, net in the accompanying consolidated statements of operations. The Company will continue to adjust the liability for changes in the fair value of these warrants until the earlier of the exercise of the warrants, the expiration of the warrants, or until such time as the warrants are no longer considered liability instruments.
Leases		Leases The Company leases office space and laboratory facilities under non-cancelable incentives or allowances, these terms are applied in the determination of straight-line rent expense over the lease period.
Research and Development	Research and Development Research and development costs are expensed as incurred and consist primarily of salaries, benefits and other staff-related costs, including associated stock-based compensation, laboratory supplies, nonclinical and clinical studies and trials and related clinical manufacturing costs, costs related to manufacturing preparation, fees paid to other entities that conduct certain research and development activities on the Company’s behalf. Non-refundable	Research and Development Research and development costs are expensed as incurred and consist primarily of salaries, benefits and other staff-related costs, including associated stock-based compensation, laboratory supplies, nonclinical and clinical studies and trials and related clinical manufacturing costs, costs related to manufacturing preparation, fees paid to other entities that conduct certain research and development activities on the Company’s behalf. Non-refundable
Advance Payments for Research and Development Services and Accruals	Advance Payments for Research and Development Services and Accruals As part of the process of preparing its condensed consolidated financial statements, the Company is required to estimate its expenses resulting from its obligation under contracts with vendors and consultants and clinical site agreements in connection with its research and development efforts. The financial terms of these contracts are subject to negotiations which vary contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate research and development expenses in its condensed consolidated financial statements by matching those expenses with the period in which services and efforts are expended. The Company accounts for these expenses according to the progress of its research and development efforts. The Company determines advance payments for research and development services and accrual estimates through discussion with applicable personnel and outside service providers as to the progress of clinical trials, or other services completed. The Company adjusts its rate of research and development expense recognition if actual results differ from its estimates. The Company makes estimates of its advance payments and accrued expenses as of each balance sheet date in its condensed consolidated financial statements based on facts and circumstances known at that time. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of status and timing of services performed relative to the actual status and timing of services performed may vary and may result in the Company reporting amounts that are too high or too low for any particular period. Through June 30, 2021, there had been no material adjustments to the Company’s prior period estimates of advance payments and accruals for research and development expenses. The Company’s research and development advance payments and accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors.	Advance Payments for Research and Development Services and Accruals As part of the process of preparing its consolidated financial statements, the Company is required to estimate its expenses resulting from its obligation under contracts with vendors and consultants and clinical site agreements in connection with its research and development efforts. The financial terms of these contracts are subject to negotiations which vary contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company’s objective is to reflect the appropriate research and development expenses in its consolidated financial statements by matching those expenses with the period in which services and efforts are expended. The Company accounts for these expenses according to the progress of its research and development efforts. The Company determines advance payments for research and development services and accrual estimates through discussion with applicable personnel and outside service providers as to the progress of clinical trials, or other services completed. The Company adjusts its rate of research and development expense recognition if actual results differ from its estimates. The Company makes estimates of its advance payments and accrued expenses as of each balance sheet date in its consolidated financial statements based on facts and circumstances known at that time. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of status and timing of services performed relative to the actual status and timing of services performed may vary and may result in the Company reporting amounts that are too high or too low for any particular period. Through December 31, 2020, there had been no material adjustments to the Company’s prior period estimates of advance payments and accruals for research and development expenses. The Company’s research and development advance payments and accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors.
General and Administrative Costs		General and Administrative Costs General and administrative costs are expensed as incurred and include employee-related expenses including salaries, benefits, travel and non-cash
Stock-Based Compensation	Stock-Based Compensation The Company recognizes stock-based compensation expense for stock options and restricted stock unit awards on a straight-line basis over the requisite service period. The Company’s stock-based compensation costs are based upon the grant date fair value of options estimated using the Black-Scholes-Merton option pricing model. This model utilizes as inputs the estimated fair value of the underlying common stock at the measurement date, the estimated term of the stock options (weighted-average period of time that the options granted are expected to be outstanding), risk-free interest rates, expected dividends, and the expected volatility of the Company’s common stock. The Company has elected to recognize forfeitures of share-based payment awards as they occur. The Company recognizes stock-based compensation expense for stock options granted to non-employees	Stock-Based Compensation The Company recognizes stock-based compensation expense for stock options and restricted stock unit awards on a straight-line basis over the requisite service period. The Company’s stock-based compensation costs are based upon the grant date fair value of options estimated using the Black-Scholes-Merton option pricing model. This model utilizes as inputs the estimated fair value of the underlying common stock at the measurement date, the estimated term of the stock options (weighted-average period of time that the options granted are expected to be outstanding), risk-free interest rates, expected dividends, and the expected volatility of the Company’s common stock. The Company has elected to recognize forfeitures of share-based payment awards as they occur. The Company recognizes stock-based compensation expense for stock options granted to nonemployees based on the estimated fair value of the award as it is more readily measurable than the fair value of the services received.
Income Taxes		Income Taxes Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts or existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period of enactment. The Company records a valuation allowance to reduce deferred tax assets to an amount for which realization is more likely than not. The Company recognizes the tax benefit from an uncertain tax position if it is more likely than not that the tax position will be sustained upon examination by the tax authorities, based on the merits of the position. The Company does not believe any uncertain tax positions currently pending will have a material adverse effect on its consolidated financial statements nor does the Company expect any material change in its position in the next 12 months. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits.
Net Loss Per Share Attributable to Common Stockholders	Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company.	Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration of potentially dilutive securities. Diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders since the effect of potentially dilutive securities is anti-dilutive given the net loss of the Company.
Comprehensive Loss	Comprehensive Loss Comprehensive loss represents the change in the Company’s stockholders’ equity (deficit) from all sources other than investments by or distributions to stockholders. The Company has no items of other comprehensive loss; as such, net loss equals comprehensive loss.	Comprehensive Loss Comprehensive loss represents the change in the Company’s stockholders’ deficit from all sources other than investments by or distributions to stockholders. The Company has no items of other comprehensive loss; as such, net loss equals comprehensive loss.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2016-02, Leases Leases right-of-use No. 2020-05, Revenue from Contracts with Customers (Topic 606) and Leases (Topic 842): Effective Dates for Certain Entities, non-public right-of-use Recently Adopted Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) 815-40): ASU 2020-06, ASU 2020-06 removes ASU 2020-06 is	Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases Leases right-of-use 2020-05, Revenue from Contracts with Customers (Topic 606) and Leases (Topic 842): Effective Dates for Certain Entities, non-public right-of-use Recently Adopted Pronouncements In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement 2018-13,

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Summary of Fair Value, Liabilities Measured on Recurring Basis	The following table summarizes the fair value of the Company’s financial liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): December 31, 2020 Level 1 Level 2 Level 3 Total Liabilities: Redeemable convertible preferred stock warrant liabilities $ – $ – $ 2,622 $ 2,622 Total financial liabilities $ – $ – $ 2,622 $ 2,622	The following table summarizes the fair value of the Company’s financial liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): December 31, 2019 Level 1 Level 2 Level 3 Total Liabilities: Redeemable convertible preferred stock warrant liabilities $ – $ – $ 1,366 $ 1,366 Total financial liabilities $ – $ – $ 1,366 $ 1,366 December 31, 2020 Level 1 Level 2 Level 3 Total Liabilities: Redeemable convertible preferred stock warrant liabilities $ – $ – $ 2,622 $ 2,622 Total financial liabilities $ – $ – $ 2,622 $ 2,622
Summary of Change in Fair Value of Redeemable Convertible Preferred Stock Warrant Liabilities and Convertible notes	The following table summarizes the change in the fair value of the redeemable convertible preferred stock warrant liabilities for the six months ended June 30, 2021 (in thousands): Beginning balance as of December 31, 2020 2,622 Losses from changes in fair value 55 Settlement upon IPO (2,677 ) Ending balance as of June 30, 2021 $ – The following table summarizes the change in the fair value of the convertible not e Beginning balance as of December 31, 2020 $ – Issuance of convertible notes 7,500 Interest 54 Losses from changes in fair value 839 Conversion upon IPO (8,393 ) Ending balance as of June 30, 2021 $ –	The following table summarizes the change in the fair value of the redeemable convertible preferred stock warrant liabilities for the years ended December 31, 2019 and 2020 (in thousands): December 31, 2019 2020 Beginning balance $ 724 $ 1,366 Losses from changes in fair value 642 153 Exercise of warrants – (395 ) Issuance of warrants – 1,498 Ending balance $ 1,366 $ 2,622

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Schedule of prepaid expenses and other current assets	Prepaid expenses and other current assets consisted of the following (in thousands): June 30, December 31, Refundable clinical deposits $ 337 $ 672 Tax refund receivable 25 229 Prepaid insurance 3,050 47 Other prepaids and current assets 1,207 129 Total prepaid expenses and other current assets $ 4,619 $ 1,077	Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2019 2020 Refundable clinical deposits $ 1,891 $ 672 Tax refund receivable 201 229 Refundable security deposit 187 – Prepaid insurance 61 47 Other prepaids and current assets 184 129 Total prepaid expenses and other current assets $ 2,524 $ 1,077
Summary of cost and accumulated depreciation and amortization of property and equipment		The cost and accumulated depreciation and amortization of property and equipment were as follows (in thousands): December 31, 2019 2020 Laboratory and platform equipment $ 3,500 $ 4,613 Furniture and office equipment 100 100 Leasehold improvements 198 198 Construction in progress 683 1,607 Total property and equipment, gross 4,481 6,518 Less: accumulated depreciation and amortization (1,741 ) (2,818 ) Total property and equipment, net $ 2,740 $ 3,700
Schedule of accrued liabilities	Accrued liabilities consisted of the following (in thousands): June 30, December 31, Accrued professional services $ 1,340 $ 192 Accrued compensation 1,986 2,393 Accrued other liabilities 214 333 Accrued construction in progress 6 255 Total accrued liabilities $ 3,546 $ 3,173	Accrued liabilities consisted of the following (in thousands): December 31, 2019 2020 Accrued professional services $ 2,187 $ 192 Accrued compensation 1,864 2,393 Accrued other liabilities 180 333 Accrued construction in progress – 255 Total accrued liabilities $ 4,231 $ 3,173

Debt (Tables)

Debt (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Term Loan	The term loan consists of the following (in thousands): June 30, December 31, Face value of term loan $ 10,000 $ 10,000 Final payment 450 450 Unamortized debt discount associated with final payment, (1,593 ) (2,039 ) Total debt, net $ 8,857 $ 8,411 Less: short-term debt – 417 Long-term debt $ 8,857 $ 7,994	The term loan consists of the following (in thousands): December 31, Face value of term loan $ 10,000 Final payment 450 Unamortized debt discount associated with final payment, issuance date warrant fair value, and financing costs (2,039 ) Total debt, net 8,411 Less: short-term debt 417 Long-term debt $ 7,994

Redeemable Convertible Prefer_3

Redeemable Convertible Preferred Stock Warrant Liabilities (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Warrants and Rights Note Disclosure [Abstract]
Schedule of Outstanding Redeemable Convertible Preferred Stock Warrant Liabilities	The key terms of the redeemable convertible preferred stock warrant liabilities as of December 31, 2020 are summarized in the following table: Number of shares as of Exercise Expiration Exercisable into: June 30, December 31, Series A-2 – 862,471 $ 0.4996 September 30, 2021 Series C-1 – 1,124,877 0.5289 November 16, 2021 Series D redeemable convertible preferred stock – 1,762,810 0.7091 October 31, 2021 Total – 3,750,158	The key terms of the outstanding redeemable convertible preferred stock warrant liabilities as of December 31, 2019 are summarized in the following table: Number of shares Exercise Expiration Exercisable into: 2019 2020 Series A-2 1,248,551 862,471 $ 0.4996 March 31, 2021 Series B redeemable convertible preferred stock 378,111 – 0.8737 September 3, 2020 Series C-1 1,124,877 1,124,877 0.5289 November 16, 2021 Series D redeemable convertible preferred stock – 1,762,810 0.7091 October 31, 2030 Total 2,751,539 3,750,158

Redeemable Convertible Prefer_4

Redeemable Convertible Preferred Stock (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Summary of Redeemable Convertible Preferred Stock	Redeemable convertible preferred stock consisted of the following (in thousands, except share amounts) as of December 31, 2020: Redeemable Convertible Preferred Stock Shares Shares Issued Carrying Aggregate Series A-1 746,426 746,426 $ 238 $ 305 Series A-2 9,869,218 8,805,587 4,147 4,399 Series B 3,968,775 3,968,775 3,980 4,421 Series C-1 43,278,699 42,153,822 20,975 22,297 Series C-2 26,537,826 26,537,826 15,390 15,000 Series C-3 24,605,790 24,605,790 14,973 15,000 Series D 95,191,755 95,191,755 67,336 67,500 Total 204,198,489 202,009,981 $ 127,039 $ 128,922	Redeemable convertible preferred stock as of December 31, 2019 consisted of the following (in thousands, except share amounts): Redeemable Convertible Preferred Stock Shares Shares Issued Carrying Aggregate Series A-1 746,426 746,426 $ 238 $ 305 Series A-2 9,869,218 8,509,579 3,876 4,251 Series B 3,968,775 3,590,664 3,234 4,000 Series C-1 43,278,699 42,153,822 20,648 22,297 Series C-2 26,537,826 26,537,826 15,390 15,000 Series C-3 24,605,790 24,605,790 14,965 15,000 Series D 95,191,755 95,191,755 67,296 67,500 Total 204,198,489 201,335,862 $ 125,647 $ 128,353 Redeemable convertible preferred stock as of December 31, 2020 consisted of the following (in thousands, except share amounts): Redeemable Convertible Preferred Stock Shares Shares Issued Carrying Aggregate Series A-1 746,426 746,426 $ 238 $ 305 Series A-2 9,869,218 8,805,587 4,147 4,399 Series B 3,968,775 3,968,775 3,980 4,421 Series C-1 43,278,699 42,153,822 20,975 22,297 Series C-2 26,537,826 26,537,826 15,390 15,000 Series C-3 24,605,790 24,605,790 14,973 15,000 Series D 95,191,755 95,191,755 67,336 67,500 Total 204,198,489 202,009,981 $ 127,039 $ 128,922

Common Stock (Tables)

Common Stock (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Issuance, on an as-Converted Basis	The Company has reserved the following shares of common stock for issuance, on an as-converted June 30, December 31, Stock incentive plans 5,219,804 2,786,345 Redeemable convertible preferred stock – 12,605,800 Convertible notes – – Redeemable convertible preferred stock warrants – 229,034 Total 5,219,804 15,621,179	The Company has reserved the following shares of common stock for issuance, on an as-converted December 31, 2019 2020 Stock incentive plans 2,585,294 2,786,345 Redeemable convertible preferred stock 12,539,109 12,605,800 Redeemable convertible preferred stock warrants 193,583 229,034 Total 15,317,986 15,621,179

Stock Incentive Plan (Tables)

Stock Incentive Plan (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Summary of the Company's Stock Option Activity under its Stock Option Plans	A summary of the Company’s stock option activity under its stock option plans was as follows (in thousands, except share and per share data and years): Options Outstanding Shares Number of Weighted Remaining Aggregate Balance—December 31, 2020 344,456 2,441,889 $ 5.17 8.02 $ 14,844 Authorized 2,205,000 – Granted (408,464 ) 408,464 12.39 Exercised – (47,539 ) 4.61 Cancelled 32,029 (32,059 ) 4.86 Balance—June 30, 2021 2,173,021 2,770,785 $ 6.25 7.87 $ 8,660 Exercisable—June 30, 2021 – 1,316,271 $ 4.00 6.88 $ 6,388	A summary of the Company’s stock option activity under its stock option plans was as follows (in thousands, except share and per share data and y e Options Outstanding Shares Number of Weighted- Remaining Aggregate Balance—December 31, 2019 250,464 2,334,830 $ 3.29 8.37 $ 11,441 Authorized 596,414 – – Granted (902,544 ) 902,544 $ 7.94 Exercised – (395,363 ) $ 2.23 Cancelled 400,122 (400,122 ) $ 3.35 Balance—December 31, 2020 344,456 2,441,889 $ 5.17 8.02 $ 14,844 Exercisable—December 31, 2020 958,319 $ 3.01 9.76 $ 8,101
Schedule of Stock-Based Compensation Expense Recognized	Stock-based compensation expense recognized was as follows (in thousands): Three Months Six Months Ended 2021 2020 2021 2020 General and administrative $ 437 $ 2,360 $ 811 $ 2,539 Research and development 119 125 238 244 Total stock-based compensation expense $ 556 $ 2,485 $ 1,049 $ 2,783	Stock-based compensation expense recognized was as follows (in thousands): Year Ended 2019 2020 Research and development $ 341 $ 488 General and administrative 453 3,153 Total stock-based compensation expense $ 794 $ 3,641
Schedule of Fair Value of Stock Option Awards Granted to Employees	The fair value of stock option awards granted to employees was estimated at the date of grant using a Black-Scholes-Merton option pricing model with the following assumptions: Three Months Ended Six Months Ended 2021 2020 2021 2020 Expected term (in years) 6.1 6.1 6.1 6.1 Expected volatility 59.2-85.5% 56.4-59.7% 59.2-85.5% 56.4-59.7% Risk-free interest rate 0.79-0.86% 0.36-0.41% 0.42-0.92% 0.36-1.55% Expected dividends – – – –	The fair value of stock option awards granted to employees was estimated at the date of grant using a Black-Scholes-Merton option pricing model with the following assumptions: Year Ended December 31, 2019 2020 Expected term (in years) 6.1 6.1 Expected volatility 54.3% – 57.7% 56.4% – 60.9% Risk-free interest rate 1.62% – 2.44% 0.27% – 1.55% Expected dividends – –

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Summary of Components of Loss	The components of loss before taxes were as follows (in thousands): Year Ended 2019 2020 Domestic $ (42,039 ) $ (45,801 ) Foreign 210 4 Total loss before provision for income tax $ (41,829 ) $ (45,797 )
Summary of Provision for Income Taxes	The provision for income taxes consisted of the following (in thousands): Year Ended 2019 2020 Current: Federal $ – $ – State 1 1 Foreign 29 – Total current tax expense $ 30 $ 1
Summary of Reconciliation of Income Tax Computed at Federal Statutory Rates	Reconciliation of income tax computed at federal statutory rates to the reported provision for income taxes was as follows (in thousands): Year Ended 2019 2020 Tax provision at U.S. statutory rate $ (8,784 ) $ (9,617 ) Permanent differences 321 695 Change in valuation allowance 9,609 9,374 Research and development credits (985 ) (849 ) Other (131 ) 398 Provision for income taxes $ 30 $ 1
Summary of Components of the Company's Deferred Income Taxes	Significant components of the Company’s deferred income taxes at December 31, 2019 and 2020 are shown below (in thousands): December 31, 2019 2020 Deferred tax assets: Net operating losses $ 17,199 $ 25,239 Research and development and other tax credits 3,533 4,740 Other 1,120 1,244 Gross deferred tax assets 21,852 31,223 Less valuation allowance (21,849 ) (31,223 ) Total deferred tax assets 3 – Deferred tax liabilities: Fixed assets (3 ) – Gross deferred tax liabilities (3 ) – Net deferred tax asset $ – $ –
Summary of Reconciliation of the Changes in the Unrecognized Tax Benefit	The following table presents a reconciliation of the changes in the unrecognized tax benefit (in thousands): Balance as of December 31, 2018 $ 892 Increases related to prior year tax positions 94 Increases related to current year tax positions 619 Balance as of December 31, 2019 1,605 Increases related to prior year tax positions 9 Increases related to current year tax positions 534 Balance as of December 31, 2020 $ 2,148

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Outstanding Shares of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders	The following outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share attributable to common stockholders for the periods presented because their effect would have been anti-dilutive: Six Months Ended June 30, 2021 2020 Redeemable convertible preferred stock on an as-converted – 12,541,340 Redeemable convertible preferred stock warrants on an as-converted basis – 185,889 Convertible notes on an as-converted – – Stock options to purchase common stock 2,770,785 3,033,480 Total 2,770,785 15,760,709	The following outstanding shares of potentially dilutive securities were excluded from the computation of the diluted net loss per share attributable to common stockholders for the periods presented because their effect would have been anti-dilutive: Year Ended 2019 2020 Redeemable convertible preferred stock on an as-converted 12,539,109 12,605,800 Redeemable convertible preferred stock warrants on an as-converted 193,583 229,034 Stock options to purchase common stock 2,334,830 2,441,889 Total 15,067,522 15,276,723

Organization and Description _2

Organization and Description of Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 23, 2021	Apr. 30, 2021	Mar. 31, 2021	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Date of incorporation					Jul. 24, 2008	Jul. 24, 2008
Proceeds from initial public offering, net of issuance costs					$ 71,997
Proceeds from issuance of common stock, net of underwriters discount and commissions					$ 71,997
Reverse stock split, description					effect a reverse split of shares of the Company’s common stock on an one-for-16.37332 basis, which was effected on April 16, 2021 (the “Reverse Stock Split”). The number of authorized shares and the par values of the common stock and redeemable convertible preferred stock were not adjusted as a result of the Reverse Stock Split. In connection with the Reverse Stock Split, the conversion ratio for the Company’s outstanding redeemable convertible preferred stock was proportionately adjusted such that the common stock issuable upon conversion of such preferred stock was decreased in proportion to the Reverse Stock Split.
Proceeds from issuance or sale of equity, debt and warrants					$ 214,500
Cash				$ 60,948	60,948	$ 7,095	$ 37,001
Retained Earnings (Accumulated Deficit)				(165,035)	(165,035)	(138,262)	$ (92,464)
Cash						7,100
Cash used in operations						$ 39,200
Common Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Conversion of redeemable convertible preferred stock to common stock upon initial public offering, Shares	12,605,800
Common shares exercised	61,515
Common Stock | Avenue Venture Opportunities Fund L P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Conversion of warrant, shares converted	107,663
Warrant to Purchase Common Stock [Member] | Avenue Venture Opportunities Fund L P
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Conversion of warrant, shares converted	1,987,348
Convertible Notes [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Conversion of redeemable convertible preferred stock to common stock upon initial public offering, Shares			559,585
Conversion of convertible notes, amout converted			$ 7,500
Discount of initial public offering price			10.00%
Initial public offering
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Proceeds from initial public offering, net of underwriters' discounts and commissions, Shares	5,333,334
Shares price per share	$ 15
Proceeds from initial public offering, net of issuance costs	$ 72,000	$ 72,000
Payments of stock issuance offering costs	2,400
Payment of underwriting discounts, commissions	5,600
Proceeds from issuance of common stock, net of underwriters discount and commissions	$ 72,000	$ 72,000
Conversion of convertible notes, amout converted				127,168
Remaining borrowing capacity				$ 50,000	$ 50,000

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2021USD ($)segment	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Number of operating segments | segment	1	1
Deferred offering costs	$ 2,400,000	$ 0
Percentage of research and development expenditures of its Australian subsidiary		43.50%
Unrecognized tax benefits, income tax penalties and interest accrued		$ 0
Prepaid Expenses and Other Current Assets
Debt Instrument [Line Items]
Accounts receivable, related parties		57,000	$ 39,000
Research Tax Credit Carryforward
Debt Instrument [Line Items]
Tax Credit Carryforward, Amount		$ 15,000	$ 134,000

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value, Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities		$ 2,622	$ 1,366
Redeemable Convertible Preferred Stock Warrant Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities	$ 0	2,622	1,366	$ 724
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities		0	0
Level 1 [Member] | Redeemable Convertible Preferred Stock Warrant Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities		0	0
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities		0	0
Level 2 [Member] | Redeemable Convertible Preferred Stock Warrant Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities		0	0
Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities		2,622	1,366
Level 3 [Member] | Redeemable Convertible Preferred Stock Warrant Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities		$ 2,622	$ 1,366

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Change in Fair Value of Redeemable Convertible Preferred Stock Warrant Liabilities and Convertible notes (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Beginning balance	$ 2,622	$ 1,366
Exercise of warrants			$ 0
Issuance of warrants		10,000	0
Ending balance		2,622	1,366
Redeemable Convertible Preferred Stock Warrant Liability [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Beginning balance	2,622	1,366	724
Losses from changes in fair value	55	153	642
Exercise of warrants		(395)
Issuance of warrants		1,498
Liabilities fair value settlement upon IPO	(2,677)
Ending balance	0	2,622	$ 1,366
Convertible Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Beginning balance	0
Issuance of convertible notes	7,500
Liabilities fair value interest	54
Losses from changes in fair value	839
Liabilities fair value conversion upon IPO	(8,393)
Ending balance	$ 0	$ 0

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Refundable clinical deposits	$ 337	$ 672	$ 1,891
Tax refund receivable	25	229	201
Refundable security deposit		0	187
Prepaid insurance	3,050	47	61
Other prepaids and current assets	1,207	129	184
Total prepaid expenses and other current assets	$ 4,619	$ 1,077	$ 2,524

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Cost and Accumulated Depreciation and Amortization of Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		$ 6,518	$ 4,481
Less: accumulated depreciation and amortization		(2,818)	(1,741)
Total property and equipment, net	$ 3,408	3,700	2,740
Laboratory and platform equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		4,613	3,500
Furniture and office equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		100	100
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		198	198
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		$ 1,607	$ 683

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Accrued professional services	$ 1,340	$ 192	$ 2,187
Accrued compensation	1,986	2,393	1,864
Accrued other liabilities	214	333	180
Accrued construction in progress	6	255	0
Total accrued liabilities	$ 3,546	$ 3,173	$ 4,231

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation, Depletion and Amortization	$ 1,100,000	$ 722,000

Commitments and Contingencies (

Commitments and Contingencies (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2017ft²
Commitments And Contingencies Disclosure [Abstract]
Non cancelable operating lease area | ft²							11,256
Remaining future minimum lease payments	$ 800,000		$ 800,000		$ 1,200,000
Percentage increase in rent payable monthly			3.00%		3.00%
Operating lease expiration date			Aug. 31, 2022		Aug. 31, 2022
Rent expenses	$ 175,000	$ 188,000	$ 349,000	$ 344,000	$ 632,000	$ 601,000

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)	Mar. 31, 2021	Nov. 05, 2020	Mar. 31, 2021	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Jul. 02, 2021	Apr. 01, 2020
Debt Instrument [Line Items]
Term of loan		36 months
Net proceeds from issuance of term loan					$ 1,500,000	$ 1,500,000
Financing cost				$ 299,000	299,000	299,000
Interest expense				509,000	999,000	303,000
Face value of term loan				10,000,000	10,000,000	10,000,000
Carrying amount of term loan				450,000	450,000	450,000
Class of warrants and rights issued during the period						$ 10,000,000	$ 0
Avenue Venture Opportunities Fund, L.P [Member]
Debt Instrument [Line Items]
Equity method investment aggregate cost		$ 10,000,000
Payroll Protection Program Loan [Member]
Debt Instrument [Line Items]
Maximum credit commitment									$ 1,100,000
Avenue Term Loan [Member]
Debt Instrument [Line Items]
Face value of term loan				10,450,000	10,450,000
Debt instrument, fair value				11,000,000	11,000,000
Convertible Notes On Conversion Basis [Member]
Debt Instrument [Line Items]
Conversion of convertible notes to common shares at IPO			559,585
I P O [Member]
Debt Instrument [Line Items]
Remaining borrowing capacity				50,000,000	50,000,000
Carrying value of convertible notes	$ 8,400,000		$ 8,400,000
Term Loan [Member]
Debt Instrument [Line Items]
Term of loan		36 months
Maximum credit commitment								$ 50,000,000
Current borrowing capacity		$ 10,000,000						20,000,000
Remaining borrowing capacity		$ 10,000,000						$ 10,800,000
Debt instrument interest rate stated percentage		11.00%
Final principal payment		$ 450,000
Term Loan [Member] | Series D Preferred Stock [Member]
Debt Instrument [Line Items]
Granted warrants for the purchase of shares		1,762,810
Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Maximum credit commitment		$ 20,000,000
Term Loan [Member] | Minimum [Member] | I P O [Member]
Debt Instrument [Line Items]
Gross proceeds		$ 75,000,000
Convertible Promissory Notes [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	5.00%		5.00%
Face value of term loan	$ 7,500,000		$ 7,500,000
Debt instrument, maturity date			Dec. 31, 2021
Interest expense, borrowings				$ 27,000	$ 54,000
Debt instrument, increase (decrease)	$ 839,000

Debt - Schedule of Term Loan (D

Debt - Schedule of Term Loan (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Face value of term loan	$ 10,000,000	$ 10,000,000
Final payment	450,000	450,000
Unamortized debt discount associated with final payment, issuance date warrant fair value, and financing costs	(1,593,000)	(2,039,000)
Total debt, net	8,857,000	8,411,000
Less: short-term debt	0	417,000
Long-term debt	$ 8,857,000	$ 7,994,000

Redeemable Convertible Prefer_5

Redeemable Convertible Preferred Stock Warrant Liabilities - Schedule of Outstanding Redeemable Convertible Preferred Stock Warrant Liabilities (Details) - $ / shares	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Class Of Warrant Or Right [Line Items]
Redeemable convertible preferred stock warrant liabilities, Number of shares outstanding	0	3,750,158	2,751,539
Series A-2 Redeemable Convertible Preferred Stock [Member]
Class Of Warrant Or Right [Line Items]
Redeemable convertible preferred stock warrant liabilities, Number of shares outstanding	0	862,471	1,248,551
Redeemable convertible preferred stock warrant liabilities, Exercise Price	$ 0.4996	$ 0.4996
Redeemable convertible preferred stock warrant liabilities, Expiration	Sep. 30, 2021	Mar. 31, 2021
Series B Redeemable Convertible Preferred Stock [Member]
Class Of Warrant Or Right [Line Items]
Redeemable convertible preferred stock warrant liabilities, Number of shares outstanding		0	378,111
Redeemable convertible preferred stock warrant liabilities, Exercise Price		$ 0.8737
Redeemable convertible preferred stock warrant liabilities, Expiration		Sep. 3, 2020
Series C-1 Redeemable Convertible Preferred Stock [Member]
Class Of Warrant Or Right [Line Items]
Redeemable convertible preferred stock warrant liabilities, Number of shares outstanding	0	1,124,877	1,124,877
Redeemable convertible preferred stock warrant liabilities, Exercise Price	$ 0.5289	$ 0.5289
Redeemable convertible preferred stock warrant liabilities, Expiration	Nov. 16, 2021	Nov. 16, 2021
Series D Redeemable Convertible Preferred Stock [Member]
Class Of Warrant Or Right [Line Items]
Redeemable convertible preferred stock warrant liabilities, Number of shares outstanding	0	1,762,810	0
Redeemable convertible preferred stock warrant liabilities, Exercise Price	$ 0.7091	$ 0.7091
Redeemable convertible preferred stock warrant liabilities, Expiration	Oct. 31, 2021	Oct. 31, 2030

Redeemable Convertible Prefer_6

Redeemable Convertible Preferred Stock Warrant Liabilities - Additional Information (Details) - shares	Sep. 30, 2021	Apr. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Class Of Warrant Or Right [Line Items]
Expected volatility rate, minimum			46.40%	46.00%	46.00%
Expected volatility rate, maximum			103.00%	116.00%	58.00%
Risk-free interest rate, minimum			0.04%	0.10%	1.60%
Risk-free interest rate, maximum			0.24%	2.80%	2.50%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period				90,072
Series A-2 Redeemable Convertible Preferred Stock [Member]
Class Of Warrant Or Right [Line Items]
Warrant exercised		61,515
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	862,471			296,008
Series B Redeemable Convertible Preferred Stock [Member]
Class Of Warrant Or Right [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period				378,111
Series D Preferred Stock [Member]
Class Of Warrant Or Right [Line Items]
Warrant exercised		107,663

Redeemable Convertible Prefer_7

Redeemable Convertible Preferred Stock - Summary of Redeemable Convertible Preferred Stock (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized	0	204,198,489	204,198,489
Shares Issued and Outstanding		202,009,981	201,335,862
Carrying Value		$ 127,039	$ 125,647
Redeemable convertible preferred stock, liquidation preference value		$ 128,922	$ 128,353
Series A-1 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized		746,426	746,426
Shares Issued and Outstanding		746,426	746,426
Carrying Value		$ 238	$ 238
Redeemable convertible preferred stock, liquidation preference value		$ 305	$ 305
Series A-2 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized		9,869,218	9,869,218
Shares Issued and Outstanding		8,805,587	8,509,579
Carrying Value		$ 4,147	$ 3,876
Redeemable convertible preferred stock, liquidation preference value		$ 4,399	$ 4,251
Series B Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized		3,968,775	3,968,775
Shares Issued and Outstanding		3,968,775	3,590,664
Carrying Value		$ 3,980	$ 3,234
Redeemable convertible preferred stock, liquidation preference value		$ 4,421	$ 4,000
Series C-1 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized		43,278,699	43,278,699
Shares Issued and Outstanding		42,153,822	42,153,822
Carrying Value		$ 20,975	$ 20,648
Redeemable convertible preferred stock, liquidation preference value		$ 22,297	$ 22,297
Series C-2 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized		26,537,826	26,537,826
Shares Issued and Outstanding		26,537,826	26,537,826
Carrying Value		$ 15,390	$ 15,390
Redeemable convertible preferred stock, liquidation preference value		$ 15,000	$ 15,000
Series C-3 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized		24,605,790	24,605,790
Shares Issued and Outstanding		24,605,790	24,605,790
Carrying Value		$ 14,973	$ 14,965
Redeemable convertible preferred stock, liquidation preference value		$ 15,000	$ 15,000
Series D Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized		95,191,755	95,191,755
Shares Issued and Outstanding		95,191,755	95,191,755
Carrying Value		$ 67,336	$ 67,296
Redeemable convertible preferred stock, liquidation preference value		$ 67,500	$ 67,500

Redeemable Convertible Prefer_8

Redeemable Convertible Preferred Stock - Additional Information (Details)	Apr. 30, 2021USD ($)shares	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)$ / shares	Dec. 31, 2019USD ($)
Temporary Equity [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio				0.12863
Preferred Stock, Conversion Price, Increase				$ 1.0636
Proceeds from Issuance of Private Placement | $				$ 50,000,000
Preferred Stock, Dividend Rate, Percentage				8.00%
Series A-1 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Temporary equity, accretion to redemption value | $		$ 0	$ 0	$ 0	$ 0
Preferred Stock, Liquidation Preference Per Share				$ 0.4091
Series A-2 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Temporary equity, accretion to redemption value | $		0	0	$ 0	0
Preferred Stock, Liquidation Preference Per Share				$ 0.4996
Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Temporary equity, accretion to redemption value | $		0	0	$ 0	0
Temporary equity, accretion of dividends | $		$ 129,000	$ 256,000	$ 518,000	$ 505,000
Number of common stock shares issued upon conversion | shares	12,605,800
Carrying value reclassified to equity | $	$ 127,200,000
Series C1 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock, Liquidation Preference Per Share				$ 0.5289
Series C2 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock, Liquidation Preference Per Share				0.5652
Series C3 Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock, Liquidation Preference Per Share				0.6096
Series D Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock, Liquidation Preference Per Share				0.7091
Series B Preferred Stock [Member]
Temporary Equity [Line Items]
Preferred Stock, Liquidation Preference Per Share				$ 1.1140

Common Stock - Additional Infor

Common Stock - Additional Information (Details) - Common Stock [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Common stock, voting rights	Each share of common stock has the right to one vote.	Each share of common stock has the right to one vote.
Cash dividends declared	$ 0	$ 0

Common Stock - Schedule of Rese

Common Stock - Schedule of Reserved Shares of Common Stock for Issuance, on an as-Converted Basis (Details) - shares	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Common stock, reserved for future issuance	5,219,804	15,621,179	15,317,986
Stock Incentive Plans [Member]
Common stock, reserved for future issuance	5,219,804	2,786,345	2,585,294
Redeemable Convertible Preferred Stock [Member]
Common stock, reserved for future issuance	0	12,605,800	12,539,109
Convertible Notes [Member]
Common stock, reserved for future issuance		0
Redeemable Convertible Preferred Stock Warrant [Member]
Common stock, reserved for future issuance	0	229,034	193,583
Redeemable Convertible Preferred Stock Warrant [Member] | Convertible Notes [Member]
Common stock, reserved for future issuance	0

Stock Incentive Plan - Addition

Stock Incentive Plan - Additional Information (Details) - USD ($)	Nov. 01, 2018	May 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options outstanding			2,770,785		2,770,785		2,441,889	2,334,830
Common stock, reserved for future issuance			5,219,804		5,219,804		15,621,179	15,317,986
Number of shares available for grant			2,173,021		2,173,021		344,456	250,464
Increase in number of shares available for future grant		596,414
Number of share options granted during the period		276,843			408,464		902,544
Stock options, grants in period, weighted-average exercise price					$ 12.39		$ 7.94
Accelerated cost					$ 2,100,000		$ 2,100,000
Stock options, exercises in period, total intrinsic value					202,000,000	$ 26,000,000	3,700,000	$ 94,000,000
Stock options, vested in period, fair value					1,300,000	900,000	1,100,000	451,000
Stock options. grants in period, grant date fair value					$ 2,900,000	$ 3,800,000	$ 3,900,000	$ 3,100,000
Stock options, grants in period, weighted-average grant date fair value					$ 7.22	$ 4.42	$ 4.24	$ 2.34
Unvested stock options, cost not yet recognized, amount			$ 5,000,000		$ 5,000,000		$ 5,300,000
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock Option, Exercise Price, Increase		$ 11.47
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock Option, Exercise Price, Increase		$ 13.76
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested award, cost not yet recognized, period for recognition					2 years 9 months 18 days		3 years
Expected dividend yield			0.00%	0.00%	0.00%	0.00%	0.00%
Stock Options [Member] | Chief Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period		48 months
Number of share options granted during the period		715,358
Stock options, grants in period, weighted-average exercise price		$ 7.86
2008 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Plan term					10 years		10 years
Stock options outstanding			604,267		604,267		634,788	1,032,840
2018 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options outstanding			2,034,734		2,034,734		1,807,101	1,301,989
Award expiration period	10 years
Common stock, reserved for future issuance			753,645		753,645		753,645
Number of shares available for grant							344,456	250,464
Percentage of fair value per share of the Company's common stock on the date of grant	100.00%
Percentage of Voting Interests Acquired	10.00%
Percentage of Outstanding Stock Maximum on the date of Grants	110.00%
2021 Equity Incentive Plan Policies [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options outstanding			131,621		131,621
Common stock, reserved for future issuance			2,205,000		2,205,000
Number of shares reserved for issuance.					2,272,613
Percentage of total number of outstanding shares of common stock					5.00%
2021 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, reserved for future issuance			276,000		276,000

Stock Incentive Plan - Summary

Stock Incentive Plan - Summary of the Company's Stock Option Activity under its Stock Option Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	6 Months Ended	12 Months Ended
	May 31, 2020	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Shares Available for Grant, Beginning Balance		344,456	250,464
Shares Available for Grant, Authorized		2,205,000	596,414
Shares Available for Grant, Granted		(408,464)	(902,544)
Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Exercised During Period			0
Shares Available for Grant, Cancelled		32,029	400,122
Shares Available for Grant, Ending Balance		2,173,021	344,456	250,464
Number of Options, Beginning Balance		2,441,889	2,334,830
Number of Options, Granted	276,843	408,464	902,544
Issuance of common stock upon the exercise of stock options, Shares		(47,539)	(395,363)
Number of Options, Cancelled		(32,059)	(400,122)
Number of Options, Ending Balance		2,770,785	2,441,889	2,334,830
Number of Options, Exercisable		1,316,271	958,319
Weighted-Average Exercise Price, Beginning Balance		$ 5.17	$ 3.29
Weighted-Average Exercise Price, Granted		12.39	7.94
Weighted-Average Exercise Price, Exercised		4.61	2.23
Weighted-Average Exercise Price, Cancelled		4.86	3.35
Weighted-Average Exercise Price, Ending Balance		6.25	5.17	$ 3.29
Weighted-Average Exercise Price, Exercisable		$ 4	$ 3.01
Remaining Contractual Term (Years), Balance		7 years 10 months 13 days	8 years 7 days	8 years 4 months 13 days
Remaining Contractual Term (Years), Exercisable		6 years 10 months 17 days	9 years 9 months 3 days
Aggregate Intrinsic Value, Beginning Balance		$ 14,844	$ 11,441
Aggregate Intrinsic Value, Ending Balance		8,660	14,844	$ 11,441
Aggregate Intrinsic Value, Exercisable		$ 6,388	$ 8,101

Stock Incentive Plan - Schedule

Stock Incentive Plan - Schedule of Stock-Based Compensation Expense Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 556	$ 2,485	$ 1,049	$ 2,783	$ 3,641	$ 794
Research and Development [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	119	125	238	244	488	341
General and Administrative [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 437	$ 2,360	$ 811	$ 2,539	$ 3,153	$ 453

Stock Incentive Plan - Schedu_2

Stock Incentive Plan - Schedule of Fair Value of Stock Option Awards Granted to Employees (Details) - Stock Options [Member]	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 months 3 days	6 months 3 days	6 months 3 days	6 months 3 days	6 years 1 month 6 days	6 years 1 month 6 days
Expected dividends	0.00%	0.00%	0.00%	0.00%	0.00%
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	59.20%	56.40%	59.20%	56.40%	56.40%	54.30%
Risk-free interest rate	0.79%	0.36%	0.42%	0.36%	0.27%	1.62%
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility	85.50%	59.70%	85.50%	59.70%	60.90%	57.70%
Risk-free interest rate	0.86%	0.41%	0.92%	1.55%	1.55%	2.44%

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Loss Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Provision for income taxes	$ (15,482)	$ (12,923)	$ (26,773)	$ (22,681)	$ (45,797)	$ (41,829)
Domestic [Member]
Provision for income taxes					(45,801)	(42,039)
Foreign [Member]
Provision for income taxes					$ 4	$ 210

Income Taxes - Summary of Provi

Income Taxes - Summary of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	$ 0
State	1	$ 1
Foreign		29
Total current tax expense	$ 1	$ 30

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Income Tax Computed at Federal Statutory Rates (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax provision at U.S. statutory rate					$ (9,617)	$ (8,784)
Permanent differences					695	321
Change in valuation allowance					9,374	9,609
Research and development credits					(849)	(985)
Other					398	(131)
Provision for income taxes	$ 0	$ 1	$ 0	$ 0	$ 1	$ 30

Income Taxes - Summary of Com_2

Income Taxes - Summary of Components of the Company's Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating losses	$ 25,239	$ 17,199
Research and development and other tax credits	4,740	3,533
Other	1,244	1,120
Gross deferred tax assets	31,223	21,852
Less valuation allowance	(31,223)	(21,849)
Total deferred tax assets		3
Deferred tax liabilities:
Fixed Assets		(3)
Gross deferred tax liabilities		$ (3)
Net deferred tax asset	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Percentage of increase the ownership of certain shareholders over the three year period
Percentage Of Increase The Ownership Of Certain Shareholders Over The Three Year Period		50.00%
Increase (decrease) in the valuation allowance		$ 9,400,000	$ 9,600,000
Research Tax Credit Carryforward
Percentage of increase the ownership of certain shareholders over the three year period
Tax Credit Carryforward, Amount	$ 15,000	15,000	$ 134,000
Federal Tax Authority [Member]
Percentage of increase the ownership of certain shareholders over the three year period
Operating Loss Carryforwards	21,400,000	21,400,000
Federal Tax Authority [Member] | Indefinitely [Member]
Percentage of increase the ownership of certain shareholders over the three year period
Operating Loss Carryforwards	98,700,000	98,700,000
Federal Tax Authority [Member] | Research Tax Credit Carryforward
Percentage of increase the ownership of certain shareholders over the three year period
Tax Credit Carryforward, Amount	$ 6,500,000	$ 6,500,000
Federal Tax Authority [Member] | Minimum [Member]
Percentage of increase the ownership of certain shareholders over the three year period
Operating Loss Carry forwards Expiration Year	2028 years
Federal Tax Authority [Member] | Maximum [Member]
Percentage of increase the ownership of certain shareholders over the three year period
Operating Loss Carry forwards Expiration Year	2029 years

Income Taxes - Summary of Reco

Income Taxes - Summary of Reconciliation of the Changes in the Unrecognized Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Uncertainties [Abstract]
Beginning balance	$ 1,605	$ 892
Increases related to prior year tax positions	9	94
Increases related to current year tax positions	534	619
Ending balance	$ 2,148	$ 1,605

Defined Contribution Plan - Add

Defined Contribution Plan - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Maximum Employee's Contribution, Percent			4.00%		4.00%
Expense, Defined Contribution Plan	$ 70,000	$ 62,000	$ 181,000	$ 157,000	$ 277,000	$ 197,000

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Schedule of Outstanding Shares of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	2,770,785	15,760,709	15,276,723	15,067,522
Redeemable Convertible Preferred Stock on an as-Converted Basis [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	12,541,340	12,605,800	12,539,109
Redeemable Convertible Preferred Stock Warrants on an as Converted Basis [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	185,889	229,034	193,583
Convertible Notes On Conversion Basis [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	0
Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	2,770,785	3,033,480	2,441,889	2,334,830

Subsequent Event (Additional In

Subsequent Event (Additional Information) (Details) - USD ($)	Nov. 05, 2020	Apr. 30, 2021	Mar. 31, 2021	May 31, 2020	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2020	Jul. 02, 2021	Dec. 31, 2019
Subsequent Event [Line Items]
Term of loan	36 months
Final Payment Percentage of Principal Amount Term Loan							6.50%
Term Loan Final Payment Description							The Company will be required to make a final payment of 6.5% of the original principal amount of the Term Loans drawn, payable on the earlier of (i) the Maturity Date, (ii) the acceleration of any Term Loans, or (iii) the prepayment of the Term Loans (the “Final Payment”). The Company may prepay all, but not less than all, of the Term Loans upon 30 days’ advance written notice to Oxford, provided that the Company will be obligated to pay a prepayment fee equal to (i) 3.0% of the principal amount of the applicable Term Loan prepaid on or before the first anniversary of the applicable funding date, (ii) 2.0% of the principal amount of the applicable Term Loan prepaid between the first and second anniversary of the applicable funding date, and (iii) 1.0% of the principal amount of the applicable Term Loan prepaid thereafter, and prior to the Maturity Date (each, a “Prepayment Fee”).
Common Stock Issued As Warrant Exercisable					19,470,914		19,470,914	755,478		360,115
Debt instrument, face amount					$ 10,000,000		$ 10,000,000	$ 10,000,000
Number of share options granted during the period				276,843			408,464	902,544
Reverse stock split, description							effect a reverse split of shares of the Company’s common stock on an one-for-16.37332 basis, which was effected on April 16, 2021 (the “Reverse Stock Split”). The number of authorized shares and the par values of the common stock and redeemable convertible preferred stock were not adjusted as a result of the Reverse Stock Split. In connection with the Reverse Stock Split, the conversion ratio for the Company’s outstanding redeemable convertible preferred stock was proportionately adjusted such that the common stock issuable upon conversion of such preferred stock was decreased in proportion to the Reverse Stock Split.
Term Loan [Member]
Subsequent Event [Line Items]
Current borrowing capacity	$ 10,000,000								$ 20,000,000
Term of loan	36 months
Debt instrument interest rate stated percentage	11.00%
Remaining borrowing capacity	$ 10,000,000								10,800,000
Term A Loan [Member] | Warrant [Member]
Subsequent Event [Line Items]
Common Stock Issued As Warrant Exercisable					71,522		71,522
Warrant Exercise Price Per Share					$ 8.389		$ 8.389
Warrant Expiration Date					Jul. 2, 2031		Jul. 2, 2031
Term C Loan [Member]
Subsequent Event [Line Items]
Net revenue							$ 15,000,000
Long-term Debt, Maturity Date					Jul. 1, 2026		Jul. 1, 2026
Term of loan							35 months
Subsequent Event [Member]
Subsequent Event [Line Items]
Number of share options granted during the period						276,843
Share-based compensation arrangement by share-based payment award, award vesting period						48 months
Reverse stock split, description		one-for-16
Subsequent Event [Member] | Minimum [Member]
Subsequent Event [Line Items]
Stock option, exercise price					$ 11.47
Subsequent Event [Member] | Maximum [Member]
Subsequent Event [Line Items]
Stock option, exercise price						$ 13.76
Subsequent Event [Member] | Promissory Note [Member]
Subsequent Event [Line Items]
Debt instrument, face amount			$ 7,500,000			$ 7,500,000
Debt instrument interest rate stated percentage			5.00%			5.00%
Debt instrument, maturity date			Dec. 31, 2021
Percentage of shares of the common stock upon a qualified public offering			90.00%			90.00%
Subsequent Event [Member] | Term Loan [Member]
Subsequent Event [Line Items]
Current borrowing capacity									20,000,000
Remaining borrowing capacity									10,800,000
Subsequent Event [Member] | Term B Loan [Member]
Subsequent Event [Line Items]
Line Of Credit Facility Additional Borrowing Loan Amount									10,000,000
Subsequent Event [Member] | Term C Loan [Member]
Subsequent Event [Line Items]
Line Of Credit Facility Additional Borrowing Loan Amount									$ 20,000,000